BULLETIN of the M~LOUR~MOF 9 NATURAL HISTORY STUDIES ON PAKISTAN REPTILES PT. 1. THE GENUS ECHIS (VIPERIDAE) Walter Auffenberg and Hafeezur Rehman Biological Sciences, Volume 35, Number 5, pp. 263-314 1991 ..7 , 16 11* If 76 -- » . ..- „5& 3* -f . I / b *S 6 :- I s I. S f . 2 * 5.0 1 . a = 4 UNIVERSITY OF FLORIDA GAINESVILLE Numbers of the BULLETIN OF THE FLORIDA MUSEUM OF NATURAL HISTORY, BIOLOGICAL SCIENCES, are published at irregular intervals. Volumes contain about 300 pages and are not necessarily completed in any one calendar year. F. WAYNE KING, EDITOR RHODA J . BRYANT, MANAGING EDHOR Communications concerning purchase or exchange of the publications and all manuscripts should be addressed to: Managing Editor, Bulletin; Florida Museum of Natural History; University of Florida; Gainesville FL 32611-2035; U.S.A. This public document was promulgated at an annual cost of $2980.40 OR $2.98 per copy. It makes available to libraries, scholars, and all interested persons the results of researches in the natural sciences, emphasizing the circum-Caribbean region. ISSN: 0071-6154 CODEN: BF 5BAS Publication date: March 20,1991 Price: $3.00 STUDIES ON PAKISTAN REPTILES PT. 1. THE GENUS ECHIS (VIPERIDAE) Walter Auffenberg and Hafeezur Rehman* ABSTRACT This is the first of a series of studies intended to analyze the geographic patterns in the meristic characters of Pakistan reptiles. This part concerns the saw-scated vipers, Echis carinams. The scales analyzed are numbers of ventrals, subcaudals, dorsal rows, rows of oblique dorsals, gulars, suboculars and supraoculars; color patterns include number of dorsal spots, ventral pattern, infralabials, lateral body and head. Maps of geographic variation in the means of each of these characters are provided and the patterns of variation within Pakistan are discussed. Each of the characters studied tends to have a different geographic distribution of mean values. However, one recurrent pattern is a rapid change in character state between Iranian Plateau populations (Chagai area, Pakistan) and those of the Quetta highland area. Coastal populations are also rather distinctive, but are generally similar to those in the Indus River Plain. Himalayan foothill populations are often similar to those of coastal areas, suggesting that these geographical peripheral populations are also peripheral in regard to genetic adaptation. In the Indus River Delta, populations can be subdivided into several distinct subgroups. The resulting mosaic of character states is attributed to historic factors concerned with changing positions of the deltaic distributaries during geologic time. Finally, the population in the Cholistan-Thar Desert at the Indo-Pakistan border is distinctive in both color and scalation. These differences are probably adaptive responses to local arid conditions. Several character states of this population and that in the Chagai Desert of northwest Pakistan are convergent. Of those climatic factors believed important within the adaptive mileau of this species, mean daily maximum and minimum temperatures during June and July (when they are most active) are considered most important. Some of the population differences probably reflect adaptations to water and heat loss. Contrary to recently published opinion, we conclude there is only one species of saw-scaled viper in Pakistan; its scientific name is Echis carinams. Within Pakistan we recognize three distinct geographic races-Ec. multisquamatus Cherlin, E. c. sochureki Stemmler and E c. astolae Mertens. The geographic distribution of characters analyzed shows that the major barrier to gene flow between E. c. sochureki and E. c. multisquamatus is the central north-south massif (Sulaiman Range, et al.). For E. c. sochureki and E. c. astolae it is the Arabian Sea, and for E. c. sochureki and E. c. carinatus (Indian Peninsula ) it is largely a matter of overall distance. In general , the race E. c. sochureki is intermediate between E. c. multisquamatus and E. c. carinatus. • Dr. Walter Auffenberg is Distinguished Service Curator, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA. Mr. Hafeezur Rehman is Biologist, Herpetology Section, Zoological Survey Department, Bl. 61, Pakistan Secretariat, Karachi 1, Pakistan Auffenberg, W., and H. Rehman. 1991. Studies on Pakistan Reptiles. Pt. 1. The Genus Echis (Viperidae). Bull. Florida Mui Nat. Hist., Biol. Sci. 35(5):263-314. 264 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) RESUMEN Este es el primero de una serie de estudios que pretenden analizar los patrones geogdficos en los caractees merfsticos de los reptiles de Pakistdn. Esta parte concierne a las vfboras de escamas aserradas (saw-scaled) Echis ca,inatus. Se analiza el numero de escamas ventrates, subcaudales, filas de escamas dorsales, filas de oblicuas dorsales, gulares, suboculares y supraoculares; los patrones de color incluyen numero de manchas dorsales, patr6n ventral, infralabiales, lados.del cuerpo y cabeza. Mapas de variaci6n geosrafica en los promedios de cada uno de estos caracteres son provistos y se discuten los patrones de variaci6n dentro de Pakistdn. Cada uno de los caracteres estudiados tiende a mostrar una distinta distribuci6n geogdfica de sus valores promedio. Sin embargo, un patr6n recurrente es un cambio rhpido en la condici6n de un caracter entre las poblaciones de la placa irani (Chagai, Pakistdn) y aquellas de la regi6n alta de Quetta. Las poblaciones de la costa son tambidn distintas pero fjeneralmente similares a las que se encuentran en la planicie del rio Indo (Indus River). Las povlaciones que ocupan el pie de montafia de los Himalaya son a menudo similares a las costeras, 10 cual sugiere que estas poblaciones geogrdficas perifdricas son tambi6n perif6ricas en cuanto a sus adaptaciones gen6ticas. En el delta del rio Indo, las poblaciones pueden subdividirse en varios subgrupos. El mosaico de condiciones de caracteres resultante es atribufdo a factores hist6rfcos relacionados al cambio de posci6n de los distributarios del delta en el tiempo geoldgico. Finalmente, la poblaci6n del desierto de Cholistan-Tar en el limite indo-pakistani es distinta en color y escamaci6n. Estas diferencias son probablemente respuestas adaptativas a condici6nes dridas locales. Varias de estas condiciones de caracter de esta poblaci6n y la del desierto Chagai en el Noroeste de Pakistdn son convergentes. Entre los factores climaticos que se creen importantes dentro el medio ambiente de esta especie, la temperaturas medias mdxima y minima durante Junio y Julio (cuando la especie es mas activa) se consideran los inds importantes. Algunas de las diferencias entre poblaciones probablemente reflejen adaptaciones a ta p6rdida de agua y calor. En contraste con opiniones recientemente publicadas, nosotros concluimos que sdio hay una especie de vfbora de escamas aserradas en Pakistdn; su nombre cientffico es Echis carinams. Dentro Pakistdn reconocemos tms razas geogrdficas-E. c. multisquamatus Cherlin, E. c. sochureki Stemmler y E. c. astolae Mertens. La distribuci6n geogrdfica de los caracteres analizados muestra que la mayor barrera para el flujo gen6tico entre E. c. sochureki y E. c. multisquanzatus es el macizo central Norte-Sur (Sulaiman Rat]~e, et al.). Para E. c. sochureki y E. c. astolae es el Mar Arhbigo, y par, E. c. sochureki and t. c. carinams (Penfnsula de la India) es por demds una cuesti6n de distancia. En general, la raza E. c. sochureki es intermedia entre E. c. multisquamatus y E. c. carinatus. TABLE OF CONTENTS Introduction 265 Material 266 Sources 266 Localities Charprt,1. Characters used previously Characters used hprp Sampls Areas Vart~tinn Geographic variation Sexual variation Summary and Discussinn Svstematics Zoogeographical implications Possible selective forces Literature Cited *%~*SEE~*~~~**STphie< Api)e.,liv AUFFENBERG & REHMAN: THE GENUS ECHIS 265 INTRODUCTION For many years all Pakistan Echis populations were considered a single species (i.e., E. cannams (Schneider) 1801; type loc. nr. Madras, India). Constable (1949) suggested that the Pakistan (and other) populations should be referred to E. cannams pyramidium (Geoffroy 1827; type loc. Egypt). Stemmler (1969) modified this arrangement by placing all Pakistan (and some other) populations in E can,lams sochureki (Stemmler 1969, type loc. Ban Kushdil Khan, nr. Pishin, Baluchistan, Pakistan). He aIso demonstrated that within the geographic confines of his new race, the populations from southern Russia were larger and possessed a distinctive scalation when compared to those from more southern parts of the range, but he did not describe them as a separate subspecies. In 1969, Mertens described E carinatus astolae from the Mekkran Coast of Pakistan (type loc. Astola Island, Baluchistan). In 1981, Cherlin described E multisquamatus from Russian Turkistan (type loc. Bayram Ali, Turkmen SSR). He referred some of his material from Chagai District, northern Baluchistan to his new species, and stated that in this same area it was sympatric with populations of E. can'nams. Following additional analysis, Cherlin (1983a) raised Stemmler's sochureki to a full species and restricted E can),ams to peninsular India. All mainland Pakistan populations (except those in northwestern Chagai) were to be called E. sochureki sochureki Stemmler; the insular form was now E. sochureki astolae Mertens. Echis carinams was divided into two races, E. c. cadnams on the Indian peninsular mainland, and E. c. sinhalensis Deraniyagala (1951) on Sri Lanka. Being committed to produce a book-length compendium of the reptiles and amphibians of Pakistan, we were anxious to determine the range and character limits of these two species in Pakistan. To do this we examined all available Echis material from Pakistan and neighboring areas. This was particularly important because no geographic sympatry of the two species believed to exist in Pakistan (Cherlin 1981) had actually been clearly demonstrated. We initially presumed that the available material (in museums and the several hundred specimens we had collected during field work for the larger project on the herpetology of Pakistan) would establish such areas of overlap. As shown below, we soon learned that such sympatry could not be demonstrated and that the current taxonomic arrangement as it applies to Pakistan is probably incorrect. The results of our studies are presented below. Mr. Colin McCarthy, British Museum of Natural History, is presently completing his broader analysis of all Echis 'can'nams" material from southern Asia and northern Africa. This important study will allow our own geographically restricted one to be placed in proper perspective. We believe our data demonstrate a pattern of variation in scalation and color character states that is significant in zoogeographic interpretations 266 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) regarding Pakistan. This study is the first of several we have planned, each covering one or more reptile taxa, through which we hope to develop a zoogeographical overview of Pakistan reptiles based on analyses of more specimens than has been available to earlier workers. MATERIAL Sources This study is based on 658 specimens from the twenty one institutions listed below. The museum source of those specimens specifically referred to are identified by the abbreviations given. The numbers in parentheses indicate the number of individuals examined in each institution. American Museum of Natural History, New York (AMNH 9). Natural History Museum, London (BMNH 11). Bombay Natural History Society (BNHS 51). California Academy of Sciences, San Fransisco (CAS 5). Field Museum of Natural History, Chicago (FMNH 21). University of Humboldt Museum, Berlin (ZMB 1). Naturhistoriches Museum, Basel (NMBA 8). Museum of Comparative Zoology, Harvard University, Cambridge (MCZ 9). Natural History Museum of Vienna (NMW 2). Pakistan Museum of Natural History, Islamabad (PMNH 2). Royal Scottish Museum, Edinburgh (RSM 17). Senckenberg Museum, Frankfurt (SMF 88). University of Florida/Florida Museum of Natural History, Gainesville (UF 28). University of Michigan Museum of Zoology, Ann Arbor (UMMZ 4). National Museum of Natural History, Washington, D.C. (USNM 11). Zoological Survey Department of Pakistan, Karachi (ZSD 328). Zoological Survey of India, Calcutta (ZSI 55). National Institute of Zoology, Academy of Science5, Leningrad (ZIN 18), and Alexander Koenig Museum, Bonn (ZFMK 5). All drawings were done by the senior author. Localities Figure 1 shows the localities from which specimens were examined. Appendix 1 provides data on museum holdings of specimens examined from different geographic locations. No specimens with general, questionable, or erroneous locality data have been included; nor have we included any literature records. AUFFENBERG & REHMAN: THE GENUS ECHIS 267 L~ ~ ~ 04 B, . 1 r 9\ .-> 1 lt. ~ 1- •• -~0~•a,(VC. 2 -t *0 t~%~' C '/b .4~,2. 00 V-* . .1. .3- Figure 1 . Map showing the localities from which specimens of Echis were examined during this study. 268 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) ACKNOWLEDGEMENTS We particularly thank the United States Fish and Wildlife Service (Washington), the Deutscher Akademischer Austauschdienst (Bonn, Germany), and the Office of Sponsored Research (University of Florida) for making funds available for us to conduct this study. To all the curators and collection managers of the institutions listed above, we extend our sincere thanks for helping us locate material, putting specimens at our disposal for study, and for the many other ways in which they have contributed to the success of this project. Finally we wish to acknowledge the support offered by our respective institutions. CHARACTERS Characters Used Previously Cherlin (1981) separated Echis multisquamatits from Echis Catinatus sochureki on the basis that the former possesses a higher number of ventral scales (mean 188.1, vs. 173.4), a greater number of dorsal scale rows (mean 37.1, vs. 32.7), lateral serrated scales (both sides added together, mean 10.3, vs. 8.8), supraocular absent (vs. present), the light-colored lateral crescent markings are connected to form a zigzag (vs. separated crescents), and a light- colored, narrow, cross-like dorsal head marking (vs. a spear or broad "cross," see Cherlin 1983a, fig. 2). In his studies of Indo-Pakistan Echis populations, Stemmler (1969) separated his Echis can-nams sochureki from congeners on the bases of being viviparous (vs. oviparous), dorsal color pattern (white spots, vs. other colors), wide head with a short snout, relatively small eyes, short tail, higher dorsal scale rows, enlarged supraoculars, head color pattern and lower number of ventral and subcaudal scales. Of these, the most important characters from the standpoint of the Pakistan material have also been studied by Cherlin. Characters Used in This Study The following characters were tabulated for all the specimens listed above: (1) number of ventral scales, (2) number of subcaudals, (3) number of dorsal scale rows, (4) number of serrated oblique dorsal scale rows, (5) number of gular scale rows, (6) number of subocular scales, (7) presence of supraoculars, (8) number of dorsal spots, (9) ventral color pattern, (10), color of infralabials and chin, (11) lateral color pattern, (12) dorsal color pattern, (13) head and nape pattern. Several of these have been used in previous studies of Echis, others are used here for the first time. When AUFFENBERG & REHMAN: THE GENUS ECHIS 269 A B Figure 2. Variation in number of gular rows. (A) two rows between the enlarged chin shields and the first ventral shield; (B) four rows. pertinent, sex was determined by dissection. Definitions for characters analyzed follow. Number of ventrals.-- The first scale immediately posterior to the last chin shield to (but not including) the anal scute. Partial scutes were counted if they were larger than one third the width of a normal scute. Number of subcaudals.-- Counts were made from the first normal-sized subcaudal behind the cloaca to, but not including the terminal spine. Specimens with a truncated tail were not included in the analyses. Number of dorsal and oblique scale rows.-- In all specimens of Echis examined, a number of lateral rows were reduced in size, inclined in orientation (oblique), and distinctly serrated. This reduction in size and the attendant close packing of these scales sometimes makes counting dorsal scale rows difficult. If the change in orientation is not followed and the person making the count continues the standard manner along the diagonal set by the first pair of dorsals bordering the ventrals, the counts may regularly be two to four scales too low. In this paper all scale row counts were made at midbody. An acceptable degree of reproducibility is attained by starting the counts caudad and reversing in the standard manner at the vertebral ridge. The number of oblique scale rows were counted on only one side and always at midbody. The oblique, smaller, serrated scales begin on scale rows three or four and continue caudo-dorsally for from two to six scale rows. The remaining dorsal scales are 270 BULLEnN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) normal in both size and position. Neonates from the same geographic area have the same number of oblique scales as adults and they seem to be serrated to the same degree. Number of gulars.-- The gular rows are those scales extending from immediately between the posterior pair of enlarged chin shields and the most anterior ventral scale (Fig. 2). They are more or less arranged in pairs, one following the other, each pair straddling the midline. Subocular development.-- In the populations examined, a series of scales always surrounds the orbit (circumorbital ring); those in the lower part of the ring are termed suboculars. The subocular count was tabulated as the least number of scales vertically in the ring below the eye and between it and the supralabials below. This least number was usually above supralabial number five, rarely four (Figs. 3,4). Supraocular shield.-- Within the circumorbital ring, the most dorsally located scale above the eye is sometimes larger (longer and often wider) than the remaining adjacent dorsal head scales. This condition was interpreted as one in which the supraocular was well developed ("yes"). In other individuals none of the scales in the dorsal section of the circumorbital series was larger than the remaining dorsal head scales; this condition was interpreted as lacking a supraocular ("no") (Fig. 4). Dorsal body color pattern.-- Figure 5 is a diagrammatic view of the dorsal scale area of Echis carinams at mid-body. Both mid-dorsal and lateral color pattern elements are indicated. The dorsal portion is comprised of a median longitudinal series of darker dorsal blotches, separated by inter-blotch patches, both of which are located on a ground color of intermediate density. Dorsal blotches vary in the density of melanin, number of blotches, and their size. Melanin density was subjectively noted. Some of the notes taken also indicated whether the scales were completely or partially darkened and whether the blotch was lighter in the center or not. Blotch size was approximated by counting the scales in both the longitudinal and transverse directions. The number of dark dorsal blotches was counted from the first one immediately after the light-colored marking on the head and nape, continuing to the last one over the cloaca (or immediately anterior to it if no spot above it). Due to considerable bilateral asymmetry in the markings, counts were always made on the right side of the vertebral ridge. If the blotches were dim their light interspaces (always evident) were used as a guide. The lateral color pattern is constructed around two longitudinal rows of smaller spots, each spot usually covering only a few scales. The lower row of smaller, usually dimmer spots is designated as I, the upper row of larger, often AUFFENBERG & REHMAN: THE GENUS ECHIS 271 20**m¥*95*ER~4, 3*5 R -J Y-\:'*i'V- T-.2 \3-·t k:,-~.L-5.I . ray#/5!LIX)~ \ES-_* 3\. ' -4 C D Figure 4. Above, lateral views of head. (A) supraocular shield differentiated from remaining head scales (BNHS 2359, Chabar, Persian Gulf); (B) supraocular not differentiated (SMF 57356, Astola Island, Baluchistan; holotype E. c. asto/ae). Below, top view of left side of head. (C) supraocular not differentiated (SMF 57356, same data as above); (D) supraocular differentiated (BN}IS 2441, Mand, Baluchistan, Pakistan). Head shape differences due to age and size. 272 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) darker spots is designated as II. I or II may be absent and this fact was noted. Spot size was estimated by counting the total number of scales covered. Finally the relative darkness of the spots in both rows was noted. A longitudinal series of lighter (usually white) marks is associated with row II (Fig. 5, see remarks below). The dorsal body color pattern was placed into an additional one of two categories: individuals with reduced melanin in the dorsal spots, the spots usually with light centers (Fig. 6A) and those with dark, clearly marked blotches (though these may vary in size) (Fig. 6C). Ventral color pattern.-- In the populations studied this character ranges from uniformly clear (no markings), to heavily spotted. The markings of each specimen were subjectively placed in one of four categories; 0 = uniform white, cream, etc., without traces of any spots; 1 = very dim spots; 2 = medium intensity spots; 3 = deeply pigmented spots (Fig. 7). Additionally, the color of the ventral markings varied from greyish brown to nearly black, and in size from small to large dots. The last two variables were not tabulated. Infralabial pattern.-- Many individuals have three dark blotches on the infralabials. Others grade from this condition to uniform white or cream. We use 0 for clear, 1 for dim, 2 for medium, and 3 for dense melanin (Fig. 8). Lateral body color pattern.-- A series of white crescentic marks usually occur on the lateral body surface in association with pattern cycle II (Fig. 6). In some parts of Pakistan the crescent tips join to form a zig-zag line ( = zig- zag "yes"), and in other areas they fail to touch ( = zig-zag "no") (Fig. 5). Additionally, the number of rows of smalllateral dark spots was tabulated for a random sample of specimens (see above and Fig. 5). Head color pattern.-- The top of the head and nape is always marked with a distinct pattern. These markings vary from an arrow- to a cross-shaped mark (Fig. 9), in which the figure may be broad or narrow. For analytic purposes, we tabulated the trident mark (Fig. 9A) as 4, and the arrow mark (Fig. 9B) as 3, the broad cross (Fig. 9C) as 2, the narrow cross as 1. Intermediate conditions are indicated by a decimal (i.e., 3.5,2.5). SAMPLE AREAS Figure 10 shows the locations and general size of sample areas chosen for this study. The geographic limits of the samples were selected primarily on the basis of sample size (museum material available), but in some cases partly on AUFFENBERG & REHMAN: THE GENUS ECHIS 273 .... 1 ZIG-ZAG :::S::E:i:i:i~c >.X'XeI·I·".~·I· ·"I".YI "YI:I:61:iILE·EI:I:~:'~ INTERBLOTCH DORSAL BLOTCH I I I. ••.a..••.d•..••.....••............................m GROUND CRESCENTS .... H Figure 5. Color pattern elements on dorsal and lateral body surfaces of Echis. i b I ~ tl K1~- 1 1 ~ fi- 11~11)11:11-lf,I,1~P~211i 1 1111.. , 4\ 1 111 1 , " 17 d'11 / 9 11- i A B C Figure 6. Major variational types of dorsal body color patterns. (A) BMNH 86-9-2-2342, Chilez ( = Chilas), Baluchistan; (B) UF 61232, Makli Hill, Sindh, showing an abnormal vertebral dark zig-zag in an otherwise typical pattern; (C) SMF 57356, Astola Island, Baluchistan, holotype E. c. astolae. 274 BULLImN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) k® 1 45 1.*3 1 ·. 4,1 * 1 *1 1 1 1 I j .-f: S 1 1 ··f« , ....4 1 1 1: 1 6-? 1 , * i ** * ./ + .' . ~,~e.j -~ ,*. 4 4:' A B f -/ ' f '71/ 'F" 1/"Fr- 'me=®r T«'«1'4*1 1 , I. 1 «eli " * *1 0 -101* *1*10 '}'i'" 9=1 1 = 1 ./ *1*10 - 1 . *5 1 *1 * 1:L-11-3) 1 6 1 C D ~~5,1 /,*lplf#*W<- tq#t»f- 2-~ .Af. 1 11: 11 I .1 ® 41 4 * - -:'* *4* 0 0 0 * E Figure 7. Ventral pattern categories used in this study. (A) uniform, or nearly so, no obvious pattern = 0, MCZ 5405A, 100 mi. S Amballa, U.P., India; (B) markings dim, small, = 1, BNHS 2437, Gosht, Baluchistan, Iran; (C) medium intensity, larger markings, = 2, MCZ 1839, Mednapur, West Bengal, India; (D) darker, larger markings, = 3, MCZ 2247, 100 mi. S Amballa, U. P., India; (IE) dark, smaller, = 4, SMF 57356, holotype, E. c. astolae, Astola Island, Baluchistan. AUFFENBERG & REHMAN: THE GENUS ECHIS 275 4/1"/2/ki/~I~/1>'18&*vfilmimMR/#late-FL FBAL/281 V.L.ym"/EFE XS#<-4/- *F-T--1 -»---:'-42; A B C D Figure 8. Infralabial pattern categories used in this study. (A) uniform, no pattern = 0, SMF 57356, holotype, Astola Island, Baluchistan; (B) dim markings = 1, SMF 63137, Nushki, Baluchistan; (C) medium intensity = 2, SMF 63136, Hingol, Baluchistan; (D) intensely pigmented = 3, SMF 55015, Turkmen SSR A B X&£Fl-0m==KF•~am<~,=am, . C D Figure 9. Head pattern categories used in this study. (A) broad cross, = 2, BNHS 2441, Mand, Baluchistan, Pakistan; (B) arrow, = 2, SMF 63136, Killi Mangal (Hingol), Baluchistan; (CD narrow cross, = 1, BMNH 86-9-21-124, Chilez, Baluchistan; (D) a rare trident pattern form (not tabulated separately, but placed with "arrow" category), SMF 57256 , holotype , E. c astdae, Astola Island, Baluchistan. 276 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) NWFP A pay ...00.. .............. L <%z '·:SS:65: ........... .... M P............1®s NWR R:R:sx««. q ·: s::·5::s::S::S:XQ:' ..:555~" T p .e.... Raj R ' SB ~rr.A NP :#BAM6::<:<.2 G u Figure 10. Location (and general size) of sample areas used in this study. Abbreviations used are as follows: A, Afghanistan; CS, Central Sindh; GT, Gosht; Gu, Gujarat; I, Islamabad; K Karachi; Ki, Kirthar Range; L, Lahore; IS, Lal Suharna National Park; M, Multan; MC, Mekkran Coast; NP, Nagar Parkar;; N, Nushki; NWFP, Northwest Frontier Province; NWR, Northwest Rajasthan. P, Panjgur; Q, Quetta; Raj, Rajasthan; 4 Rattankot; S, Shadadkot; SB, Shah Bundar; TP, Thar Parkar; Th, Thatta; Z, Zabol. AUFFENBERG & REHMAN: THE GENUS ECHIS 277 environmental differences between closely approximated geographic areas (i.e., elevation, major environment). Each of these sample areas served as the basis for all calculations and evaluations, so that all specimens available from each area were considered as constituting the same sample for computational purposes. VARIATION Geographic Variation Ventrals.-- Within Pakistan the number of ventrals vary from 145 to 189 and sample means from 155 to 189 (Islamabad and Nushki samples). The general geographic pattern produced by the sample means is shown in Figure 11. The geographic pattern is characterized by an area of high ventral counts in both northwest Baluchistan (mean 181-183) and the northern Thai Desert (mean 181) areas; and areas of low counts in both the northern mountains (154-158) and the southern part of the Thal Desert (158). The means of geographically intermediate sample areas are numerically intermediate. The means of the two areas with high mean values are significantly different from those with low means (t-test, at at least the 2 % level, see Table 1). Along the Mekkran Coast the mean number of ventrals decreases steadily from west to east and the trend is continued into adjacent coastal India (172 Gosht, Iran, to 162 in Gujarat, India). Separately, these coastal populations are significantly different in mean ventral counts from inland populations in Baluchistan and Sindh (Table 1), though the zone of high ventral counts in the coastal areas of the latter is quite narrow (Fig. 11). The trend is reversed along the frontal ranges of the Himalayas (154 NWFP to 162 Lahore), but without statistical evidence for any significant differences in the means of mountain and plains populations. There is no significant difference in mean ventrals of northern Pakistan and northern India (Ganges Plain, 157) from that in southern Pakistan and adjacent Gujarat. However, both coastal and mountain samples from India southeast of Gujarat have mean ventral counts significantly lower than those of southern Pakistan (Bombay 146, Poona 146) (Table 1). On the Indian peninsula the trend to decrease ventrals southeastward is continued, with the lowest values of all observed in the Goa sample (143; a significant difference in means occurs between the adjacent Goa-Bombay samples, p < 0.05 % level, though not between any other population pair members in the rest of the peninsula). 278 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 170 160 1 154 160 158 181 162 181 160 165 165 170 183 181168 r. -160172 172 170 172 171 158 166 158 158 170 68 16 18 162 3560 ' 158 158 Jil 162 156 160 146 147147146 155 150 148143 145 149 147 145-- ~ Figure 11. Mean number of ventral scales in Echis carinatus populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECHIS 279 In the Chagai area (Nushki sample) the high mean value (183) cannot be statistically separated from that of the ZaboI, Iran (181), and Afghanistan samples. However, the Nushki mean is very significantly different from the adjacent Quetta one (165, p < 0.001). In the same way, the high mean value of the northern NW Rajasthan sample is very significantly separated from all surrounding samples (p's all < 0.05). Several neonate samples were available for study (UF, SMF, ZSI). These samples demonstrate something of the level of variation occurring in the ventral and subcaudal scales among the siblings of single broods (Table 2). These broods were available from mothers originating in Shadatkot, Karachi, Thar Parkar, Quetta, Goa and Kerala. No significant difference between the mean number of either ventrals or subcaudals of the siblings and the means of these variables in the home area of the female was shown in t-test analyses. Subcaudals.-- Analysis of the subcaudal counts results in a geographic pattern similar to, but less pronounced than that for the ventrals (Fig. 12). The highest mean values of subcaudals are found in the non-coastal areas of Baluchistan, adjacent Iran and Afghanistan. The most significant difference in means of these populations and adjacent ones occurs between the Nushki- Quetta pair populations (means 34-29, t-test = 7.2, df 22, p < 0.001). The seaboard populations demonstrate generally low, but not significantly different values from those of the remainder of Baluchistan. Nor are any of the other values significantly different for adjacent pair members through the remainder of the country. The general trend is for values to be reduced into and through peninsular India, but with the Goa and Kerala coastal populations again showing a significantly different mean value. NW Rajasthan (and Lahore) have high mean values (33-34), but they are not significantly different by t-test analysis. Dorsal Scale Rows.-- Figure 13 shows the geographic pattern of the mean number of dorsal scale rows in Pakistan. The pattern is simple, with no demonstrable significant differences between the means of any adjacent samples. However, the general aspect is similar to that for the subcaudals. Thus the Nushki sample is statistically indiscriminate from the Afghan sample. The Indus River Valley means tend to be low, continuing into India, where peninsular samples have lower means than northern ones. However, the means of the west coast peninsular samples are not significantly different from those of the remaining ones. The NWFP and Islamabad samples are low when compared to the Indus Plains samples (but not significantly different). There is no demonstrable difference between the mean of the NW Rajasthan sample and those of surrounding areas. 280 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 30 30 30 33 34 34 29 31 34 33 29 r. 'b 33 30 29 32 3 32 31 26 29' 32 31 31 27 30 29 31 fJ A29 32 26 /5~ 30 26 28 (( 32 11 30 28 26 27 8 26 28 Figure 12. Mean numbers of Subcaudal scales in Echis carinatus populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECHIS 281 28 29 00 31 32 33 32 32 32 33 31 ri31 /-1 +J J32 33 30 30 31 28 30 28 31 28 30 30 j 28 -~ --x<~ - 30 r.. 27 29 28 27 28 27 29 25 25 25 27 Figure 13. Mean numbers of dorsal scale rows in Echis carinams populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. 282 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) Oblique Scale Rows.-- The general pattern for this character (Fig. 14) is similar to the previous one for dorsal scale rows. The two, are in fact, correlated (R = 0.88). There is no demonstrable statistical difference in means between any adjacent Pakistan population. The means of samples from eastern Iran (7), western Baluchistan (7) and Afghanistan (8) are very clearly higher than the means for any other part of the country (3-6), with the exception of NW Rajasthan (7). The lowest value (3) occurs in Nagar Parkar. In general, the Indus Valley has rather low values. Gular Scale Rows.-- In spite of the fact that the range in gular scale row variation is rather narrow, means of adjacent samples are often significantly different. The geographic pattern is shown in Figure 15. Means range from 5.0 (northwestern Baluchistan and Karachi) to 3.0 (Shah Bundar). The entire Thar Desert and Ganges areas are higher than surrounding samples, but the means are not significantly different. However, the Nushki sample mean (5.0) is significantly different from that of the Quetta sample mean (3.9; t = 9.4, df 19, p < 0.001). The Shah Bundar and adjacent Gujarat mean values (3.0,3.3) are significantly different from all the surrounding ones (p < 0.025-- < 0.001). While none of the peninsular Indian samples differ significantly from one another, that from Gujarat is clearly separable from that from Bombay (t = 6.7, df 24,p < 0.001). South along the west coast of India there are additional significantly different mean values in adjacent populations, especially that separating the Goa sample from it's neighbors (t = 5.5, df 42,p < 0.001). The Sri Lanka and Tamil Nadu mean values are also significantly different (t = 8.6, df 11,p < 0.001). Number of Subocullars.-- The lowest mean values for subocular scale rows are found in southern peninsular India and Shri Lanka and the highest ones in the northwestern parts of the range, such as Afghanistan and the border area surrounding it. Typical examples of geographic variation in subocular scalation is shown in Figure 3; the pattern of geographic variation is shown in Figure 16. Supraocular development.-- In some individuals, an enlarged supraocular scale may be present on one side and not on the other (to 25% of those with developed supraoculars). However, the majority are symmetrical. The geographic variation in the presence of enlarged supraocular scales is shown in Figure 17. Here, the pattern is one in which there are significant changes between the southern Afghanistan population (identical to Transcaspian material) and all border samples in adjacent Iran and Pakistan. The Cholistan- Thar Desert and Nagar Parkar samples are also distinctive in all individuals having a well-developed supraocular. However, the Shah Bundar sample, AUFFENBERG& REHMAN: THE GENUS ECHIS 283 876 3 4 5 5 67 4 6 4 5 7 e 7 6, 7 4 e 5 6 5 5 7 4 5 5 6 6 4 e 6 4 68 55 6 44 4 4 4 4 Figure 14 . Mean numbers of oblique scale rows in Echis carinatus populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. 284 BULLEnN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 4.5 4.0 3.5 3.2 5.0 3.0 5.0 3.9 3.6 5.0 4.0 3.8 rir. 1 4.6 4.04.0 3.9 4.3 4.0 5.04.1 4.0 4.0 4.1 3.0 4.0 4.0 3.3 4.0 \ --- 3.0 2.6 3.0 3.0__/2.6 2.2 2.7 2.6 2.7 Figure 15. Mean numbers of gular scale rows in Echis carinatur populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECHIS 285 63 2.1 -/ , / ~ /\-1 ~ 2.0 2.0 r -2.12.1. \ 46 6- <-2.0202.5 2,)2.1 2.0 71 ... - 1.3 Ji- 1.9 1.51.9 2.0 1.02.0 1.2 2.0 1.5 1.0 1.0 1.0 ---- Figure 16 . Mean minimum numbers of subocular scale rows in Echis cannatus populations studied in Pakistan (left) and in India (right), with estimated positions of isophenes of identical values. 286 BULLEI'IN FLORIDA MUSEUM NATURAL HISFORY VOL. 35(5) 33 40 ~100 ~ 50 50 \-/ 35 100 33 33 8729 35 83 76 80 75 10075 2 40 60 75 Figure 17. Mean percent of sample areas with developed supraoculars in Echis carinams populations studied in Pakistan and India, with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECmS 287 having a low proportion of individuals with well developed supraoculars, is surrounded by samples in which significantly few individuals have supraoculars. Dorsal body color pattern.-- Figure 6 shows the extremes of dorsal color pattern found in Pakistan samples. The dorsal color pattern of Pakistan saw- scaled vipers is characterized by having a series of short, light, transverse ovals across the the paravertebral area (Figs. 5,6) from just behind the head to at least above the cloaca, often onto the tail. These ovals are often broken into two paravertebral spots that are sometimes connected with a diagonal dark zone that in some individuals produces a dark vertebral zig-zag, part or all the way down the back (Fig. 6); in the Astola Island population (E. c. astolae) these markings become distinct narrow transverse bars (Fig. 6). Specimens from the adjacent Mekkran Coast population are sometimes similar, but less distinctly barred. Table 4 summarizes the most common color pattern types in each sample area. A single individual out of over 350 examined by the junior author from Makli, Sindh, was provided with three vivid longitudinal stripes, without any evidence of spot rows I and II. In Pakistan, the mean number of dorsal body spots varies from 31 (Lahore and Rattankot) to 40-41 (Cholistan-Thar Desert area). Baluchistan populations have more dorsal spots than those in the Indus Valley (Fig. 18). In spite of the low level of variation over the entire area studied, there are many statistically significant differences between adjacent population means, suggesting that this is a sensitive character, useful in differentiating Echis cannatits populations. These differences are shown in Table 3. In general, the Pakistan pattern is part of the general trend within the Indian Subcontinent, i.e., higher values northwestward and lower values southeastward. The trend into peninsular India is an extension of the Pakistan pattern, except that Goa and Kerala have a significantly lower mean number of spots of all of the remaining Indian samples. It differs most from the Tamil Nadu sample (p < 0.001). The Sri Lanka and Tamil Nadu samples are not significantly different from one another. The density and distribution of melanin in the dorsal blotches varies geographically in Pakistan, though exhibits a fair degree of variation within single populations. Character state A (Fig. 6A), in which the melanin distribution may be dense, though found on only parts of the scales making up the blotch (mean number of scales involved 13, only a few of which are completely covered), is more or less restricted to arid environments (soil types camborthids and torri- and ustipsamments, fide Atlas of Pakistan, Govt. Pakistan: Islamabad, 1986). It is most common in individuals from extreme western Punjab and the Irano-Pakistan borderlands. The most common and widespread category in Pakistan is represented as B in Figure 6. It is one in which the melanin is dense and tends to cover most scales entirely. However, the spots tend to be rather small (total 18 scales in 288 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 34 32 37 31 36 35 34 35 39 41 r# 33 \ 37 33 32 37 38 33 40 33 37 33 JA A-4 %/ 33 32 -'» '+- 33 A 30 2928 27 27 7 5 27 25 28 31 29 Figure 18. Mean numbers of dorsal body spots in Echis cannams populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECmS 289 mid-body blotches). It is found throughout most of the country, occurring on a variety of soil types (ustorthents to ustipsamments). The largest blotches are found in the population of Astola Island, Baluchistan (Fig. 6C; blotches include a mean of 22 scales at mid-body). In this population the center of the blotches are usually dark brown and the outer scales black. As expected, there is significant variation in ground color. In general, it is lightest in populations living on light-colored soils, though not necessarily darkest on the darkest soils. Within Pakistan the darkest individuals are apparently found at Parachinar, NWFP, in which the ground color is grayish brown. In most other localities it is a shade of grey, sometimes locally with tinges of greyish-yellow or pinkish-yellow in life (locally). Ventral Color Pattern.-- In general, the geographic variation in this character is the same as that exhibited by other variables described above, except that the values tend to be reversed (high means in the other patterns tend to be low means in this one). The highest mean values (darkest spots) are found in inland localities of eastern Iran (Zabol, Gosht, etc.), extreme northern Pakistan (NWFP) and western coastal India (Goa, Kerala). The lowest means (lightest ventral color) are found in central Sindh, NW Rajasthan, and the Dekkan Plateau of peninsular India. Figure 19 shows the geographic pattern of variation in this character. Table 4 gives the values and significance levels for sample pair comparisons. The density of the color of the ventral markings, or whether they even occur at all, is often rather variable within a single sample. Thus, along the Persian Gulf and Mekkran Coast (N = 38) individuals with class 0 belly pattern (clear) occur in 8 percent, class 1 in 50 percent, class 2 in 21 percent, and class 3 in 21 percent. The same level of variation can be demonstrated in the Gujarat and Rajasthan samples. On the other hand, some populations are very homogeneous in this regard, particularly those in desert areas (Nushki, Cholistan-Thar Desert, etc.), where the spots are consistently light in intensity. Of all the variables examined, the most significant interpopulational differences occur in this character. Table 4 provides pertinent data for those population pairs in which the means of the degree of ventral spotting are significantly different. Figure 19 shows that the trends established through Pakistan are continued into the adjacent parts of India. Prominent features are the slightly darker venters of those populations from both the northern Gangetic and Indus Plain in both countries, extending east to the delta of the Ganges River in West Bengal. The lightest venters are found in a somewhat diagonal strip running from the northwest to the southeast. The Goa area stands out as having significantly darker bellies than surrounding populations (Goa-Bombay, t-test, df 32, p < 0.001; Goa-Kerala, df 16,p < 0.005). 290 BULLEI'IN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 2.0 1.6 2 2.0 1.3 1.5 7 0.9 1.0 1.51.4 0.3 r.0.7 \ 1.5 1.3 2.0 1.8 1.6 1.0 6 20 1.9 1.6 20 1 6 2.4 2.6 1.8 2.0 1.8 1.9 2.0 11.8 2.5 2.5 1.0 1.0 1.0 2.0 1.7 1.9 1.5 Figure 19. Mean intensities of belly spotting in Echis cannams populations studied in Pakistan (left) and in Indian peninsula (right), with estimated positions of isophenes of identical values. AUFFENBERG & REHMAN: THE GENUS ECHIS 291 The size of the ventral spots also varies geographically. In general the spots are largest in those Pakistan populations from both coastal and northern mountain areas, and smallest in individuals from interior desertic environments. The character was not easily divisible into clearly recognizable categories and so was not treated statistically. Infralabial and genial scale color.-- While the infralabials of some Pakistan populations are more or less uniform white to light grey, others possess up to three (usually two) dark spots on the infralabial scale series. Figure 8 shows the extent of variation in the distributi6n and density of melanophores on the infralabials and genial scales. In general, those populations with the least melanin are found from northwest India west through most of central Pakistan, thence into adjoining Iran and Afghanistan. Regions in which dark infralabial spots are found are the west coast of India, coastal Pakistan, and the front ranges of the Himalayas in both these countries. Most Pakistan Echis have no melanin on the genial series on the throat; some do. When present, a dusky mark is seen on each of the scales. This character is statistically correlated with the presence of dark infralabial marks (R = 0.72) and has the same general distributional pattern, but less easy to categorize. We have not analyzed this character in detail. Darkness of the infralabials and chin is positively correlated with darkness of ventral spotting (R = 0.78). Lateral Body Color Pattern.-- The Pakistan populations can be separated into two major groups on the basis of lateral body patterns, those with light lateral zig-zag markings and those with light-colored lateral crescents (Figs. 7, 2OA, C). In the material we examined, the zig-zag condition occurs in all individuals in Chagai and adjacent Afghanistan (Fig. 21). It remains common through all of western Pakistan, being present in from 50 to 64 percent of the population. Samples from the entire Indus Valley eastward, except Lahore and Shah Bundar, lack the zig-zags entirely. Instead, the marks are represented by light inverted crescents. In the Himalayan foothills from NWFP east and into the Ganges Plain in India, the zig-zag lateral pattern is found in from 25 to 50 percent of each of the samples. The populations are thus intermediate between the two extreme character states, if not in geographic location. The coastal populations of both Iran and Pakistan are similar. Those from NWFP south along the foothills of the Sulaiman Range are intermediate in both condition and location. Along coastal Iran lateral light markings of any kind are often entirely absent, as they nearly are in insular populations in western Pakistan (i.e., Astola Island). In the eastern half of Pakistan the crescent type pattern predominates (Fig. 21). Between the two extremes (zig-zag and crescent) every gradation of intermediate condition, including bright, evident crescents connected by faint zig-zags. In some populations both zig-zag, 292 BULLETIN FLORIDA MUSEUM NATURAL HISrORY VOL. 35(5) *S: Mifi~yi-= 6- -Mil4 A B AL21*Erfuf~*,23% 9 -fin_> 5- 14 re b-1;3 f 847-f*tjiftts~12,_.1.r -r"r -r _r'zz. r,=rL.Iz-*-~ill r-Meff#,2 *-tr;*«--r- 12=352s=Z*z:tIIX/Arlrf<3(32*hAr4i9& C D Figure 20. Typical lateral body patterns. (A) dark ground color, bright narrow zig-zag, no evidence of spot row I, faint traces of spots on II, no light crescents, BNHS 2448, Dera Ishmael Khan, Punjab, Pakistan; (B) medium ground color, very dim, wide zig-zag, spot rows I and II both evident, SMF 57356, holotype E. c. astolae, Astola Island, Baluchistan; (CD light ground color, crescents present, spot row I absent, II evident, AMNH 81980, Las Beta, Baluchistan; (D) light ground color, zig-zag present, no evidence of spot rows I and II, SMF 63136, Killi Mangal (Hingol), Baluchistan. crescent and intermediates are equally common; a few individuals have both pattern cycles on their body, the zig-zag usually being found anteriorly and the crescents posteriorly. Lateral spot rows I and II also vary geographically. Over much of Pakistan, row I is completely missing or very faint, while the spots of row II may be very dark (Fig. 2OD). In western Punjab row II may also be absent or only faintly indicated (Fig. 20A). On Astola Island, both rows, with spots of medium density, are present (Fig. 2OB). AUFFENBERG & REHMAN: THE GENUS ECHIS 293 100 100 75 .7 33 125 M100 \- 12 5 17 60 64 -/ 00 00 03 0 3\ C - 0 60 50 00 200 25 0 0 O 0 0 Figure 21. Percent of sample populations with evident light lateral zig-zag. 294 BULLEnN FLORIDA MUSEUM NATURAL HISrORY VOL. 35(5) Head and Nape Color Pattern.-- Figure 9 illustrates major pattern categories seen on the head and neck of Pakistan Echis. The trident pattern (Fig. 9D) has only been seen in the Astola Island population. It is undoubtedly a modification of the wide arrow type. The most common types in Pakistan are "arrow" (Fig. 9B) and"cross" (Fig. 9A, C). In general, the narrow cross pattern is mainly found in Baluchistan and adjacent parts of Iran and Afghanistan to as far north as Turkmen SSR. In Chagai District, Baluchistan, it is found in almost all individuals. It occurs in a few individuals of all samples as far east as Andra Pradesh, India. The arrow type is most common in Sri Lanka and southern peninsular India. The wide cross type is most common in the geographically intermediate areas. It is rarely dominant in any of the Pakistan samples studied, the narrow cross type being the most prevalent. Sexual Variation An analysis of the entire sample demonstrates that there is no significant difference in the number of males and females, the sex ratio being essentially 1:1. However, Rehman (MS) shows that this sample ratio varies seasonally, depending primarily on the activity level of the males and females during different months of the year. He shows that such differences as exist are correlated primarily with different phases of the reproductive cycle in both the males and the females. A sample of 64 adult males and an equal number of adult females was randomly drawn from the largest sample available (Thatta, N = 387). On these specimens, the ventrals, subcaudals, dorsal scale rows and the number of dorsal spots were counted, keeping individuals of the two sexes separated. In addition, 66 neonates from several Pakistan and Indian localities (see Table 2 for sample sizes and localities) were similarly examined. No statistically significant differences could be demonstrated between sex and the mean of any of the variables analyzed, except the mean number of ventral scales. For this variable, the mean number in females was significantly higher at a level of about one percent (t = 2.84, df 62 ,p < 0.01), though the differences between them are slight (males 164.9 * 6.6, mean deviation 4.6 ventrals; females 169.6 t 7.7, mean deviation 8.2 ventrals. The females not only have a slightly higher mean number of ventral scales, but they are more variable (CV = 4.5 percent, as opposed to 4.0 in the males). AUFFENBERG & REHMAN: THE GENUS ECHIS 295 SUMMARY AND DISCUSSION Systematics There is no evidence to suggest that more than one species of Echis occurs within the boundaries of Pakistan. We base this on three major points. First, all the characters studied showed complete blending between them. All gradations of intermediacy were observed, although many of the intermediate conditions were restricted geographically (see below). If two species are represented in the Pakistan populations, one would expect evidence of bimodality in at least some of the characters studied. There is no such evidence in any of the characters. As an example, one of the most geographically sensitive characters we analyzed is the mean number of ventral scales in different populations. Figure 22 compares the frequency curves for ventral scales in individuals taken from Pakistan, where two species of Echis were believed to occur, and the same for central to southern Indian peninsula populations, where all workers agree that only one species is found. Neither curve shows any visual evidence of bimodality; nor is there any statistical evidence of bimodality; (moment coefficients of skewness 4.06 for the Pakistan populations and 3.92 for those from the Indian peninsula). However, both are highly kurtotic (moment coefficient of kurtosis 21.52 for the Pakistan sample and 20.90 for the extra-Pakistan samples). This flattening of the frequency distribution is caused by the demonstrated geographic variation in ventral scales in both geographic areas. Second, at least two forms previously called species (Echis carinatus and E. sochureki) have bred in captivity and produced young with completely intermediate characters (preserved hybrid HUB 18565). Third, there is no hiatus in the saw-scaled viper populations of the Indian Subcontinent from at southern Afghanistan and eastern Iran through Pakistan to the furthest reaches of Peninsular India and Sri Lanka. Nor is there any morphological evidence to support the contention that two or more species exist throughout this area. All of the characters we have studied blend completely from west to east through a series of variously intermediate steps. We see no evidence of sympatry in northern Pakistan and/or southern Afghanistan populations of Echis c. multisquan:ams and E c. sochureki (as presumed by Cherlin 1981). The name available for this species is Echis ca,inatus. However, within the Indo-Pakistan area we recognize four distinct geographic races. On the basis of priority rule, the nominate form is Echis carinatus carinatus (Schneider), found in southern peninsular India and Sri Lanka. It's northern limit is not clear to us because the geographic variation in all the characters examined in peninsular India represent broad morphoclines in which narrow zones of intergradation are not easily defined. An exception is the coastal plain 296 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 20 - - 10 - ......... .......... FR EQ UE NC Y 20 - - 10 - VENTRALS Figure 22. Frequency distribution of ventral scales. Above, Pakistan specimens only; below, peninsular India specimens only. of Goa and Kerala (India). Here each of a suite of several important characters can be shown to be distinctly different from all surrounding populations. Since the taxonomy of Indian populations is beyond the scope of this paper, we leave clarification of the nomenclatorial status of these populations to others in the future. Within Pakistan three races of Echis cannams are easily distinguished. These are to carry the names already given them by other workers in the past. One of these is to be called Echis cannatus multisquamams (Cherlin). In Pakistan it occurs in relatively "pure" form in the Chagai area of northwestern Baluchistan (Fig. 23). From here its range extends generally northwest to the type locality in Turkistan, USSR. Southward in western Baluchistan it is replaced by variously intermediate populations. It extends to the Mekkran Coast. The second race is Echis cannams sochureki Stemmler. It is found primarily in the Indo-Gangetic Plain, including most of eastern Pakistan and a large part of northern India (Fig. 23). Intermediates between it and E. c. multisquamatus occur in sometimes apparently isolated populations in mountainous areas of eastern Baluchistan and western Sindh. Unfortunately, the type locality (Pishen, Baluchistan) borders on a zone of intergradation with E. c. multisquamams. Relatively pure forms of both races occur closest to one another in the Nushki-Quetta transect, between which there is a narrow band of intergradation. Variously intermediate populations occur in a large part of coastal Baluchistan. As pointed out above, intermediate populations between E. c. sochureki and E. c. carinams occur over a large part of central India. A AUFFENBERG & REHMAN: THE GENUS ECHIS 297 MULTISQUAMATUS SOCHUREKI ASTOLAE Figure 23. Taxonomic allocation of Pakistan Echis carinams populations as applied in the current study. The clear area represents the major zone of intergradation. 298 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) third subspecies, Echis c. astolae Mertens occurs only on Astola Island, Baluchistan. Presumed intermediates between it and Echis c. sochureki X E. c. multisquamams are known from several localities along the Mekkran Coast. In many ways this is the most distinct Echis population in Pakistan, probably because of its isolated, insular distribution. Diagnoses of the races occurring in Pakistan are as follows: Echis carinams multisquamams.-- A race characterized by generally more scales in almost all parts of the body and head when compared to conspecifics; i.e., more gulars (means of local populations usually > 4.5), ventrals (means of local populations > 180), subcaudals (means 30-34), serrated oblique lateral scales (means > 7), dorsal scale rows (means > 32), and suboculars (means 2.0-2.8). The supraoculars are almost always discernable. Mean number of dorsal body spots 36-39, distinct white blotch interspaces, and a lateral color pattern, while similar to that of the other races, is provided with a rather wide, vivid light zig-zag stripe. The belly is marked with scattered dark dots; there are usually three dark spots on the infralabials. Echis carinams astolae.- A race characterized by fewer scales of the types mentioned under Echis c. multisquamatus (population mean of ventral scales 170 subcaudals 31, dorsal scale rows 31 oblique scales 5.5 gulars 4.3; supraoculars variably distinct or not). It has a body pattern that is considerably darker than that of the other races, with larger dorsal blotches (mean number 38), almost no white blotch interspaces, and in which there are two distinct rows of alternating, rather large dark spots laterally. The belly is marked with scattered small but dark dots. Only about 25 percent of the individuals have a light lateral zig-zag. Echis can'nams sochitreki.-- A much more variable race in regard to almost all of the characters studied. In local populations the mean scalation is as follows: ventrals 154-181, subcaudals 27-34, dorsal scale rows 28-32, oblique serrated scale rows 3-7, gulars 3.2-5.0, subocular scale rows 2, discernable supraoculars in from 33 to 100 percent of local populations. The mean number of dorsal spots varies from 31 to 41; white blotched interspaces are always present; belly spotting varies from none to very intense and lateral zig-zag ranges from none to about half of the individuals in some local populations. Within the range of Echis c. sochureki there are several smaller areas that are important because they contain populations unlike those typical of the subspecies. One of these areas is NWFP and northwestern Punjab. Here a series of characters are statistically different from typical E. c. sochureki. With additional material, some future workers may prefer to segregate them as a AUFFENBERG & REHMAN: THE GENUS ECHIS 299 separate race. We feel that the nomenclature used here defines the biological situation with sufficient accuracy. A second area of interest lies in the Cholistan-Thar Desert, straddling the Indo-Pakistan border. Here populations of E. c. sochureki are distinctly different from surrounding populations in both color and scalation. We believe this population represents an incipient geographic subspecies of Echis cannams that is adapted for life in sandy deserts. However, we do not think it warrants nomenclatorial status. Zoogeographical Implications Pakistan (24-37° N lat., 61-77° E long.) is a rather large country (ca. 2000 km east-west and 2200 km north-south, or ca. 805,000 kn12). It serves as a northwest to southeast link between the highly distinct biotas of the steppe, deciduous forests and deserts of temperate Central Asia and the deciduous forests and deserts of Tropical South Asia on the one hand, and as an east to west, arid to mesic link along the northern mountain ranges. Climatic conditions of Pakistan are characterized by great areas of aridity in almost all parts of the country, including some of the high northern mountain ranges. Except for the Indus River and its tributaries, large rivers and hydric or even mesic riverine forests are few and then only of small extent. Mean annual precipitation varies from less than 100 mm/year in some regions (Chagai and Cholistan-Thar Deserts) to nearly 2000 mm in others (parts of Azad Kashmir); within the range of Echis carinams, it ranges only to about 500 mm. For the most part, abundant rainfall is only experienced in the southern ranges of the northern mountain areas. Within the distribution of the saw-scaled viper, mean warm season temperatures vary from 25-38°C. This viper inhabits southern temperate, subtropical and tropical climatic regions and the following major physiographic provinces: Northern Mountains, Iranian Plateau (much of western Baluchistan), Indus Valley, the Central Mountain Borderland (separating the last two provinces), and the Coastal Plain along the Arabian Sea. The only previous study of the zoogeography of the entire Pakistan reptile fauna is by Khan (1980), which is more a compilation than an analysis and provides little new information. Other than the current study on Echis carinatus, there is no single-species analysis of reptiles for Pakistan that provides details on the probable boundaries of geographically distinct population gene pools. We would have liked to be able to analyze such boundary effects in greater detail, especially from a statistical standpoint. Unfortunately, there are no satisfactory statistical tests of ordination for zoogeographical studies (Gauch 1982). As a result, our conclusions regarding such factors rest on a series of Student t-tests between adjacent sample populations. Concordance of statistically significant differences in the mean 300 BULLETIN FLORIDA MUSEUM NATURAL HISrORY VOL. 35(5) values between the same adjacent populations suggests significant differences between them in several characteristics. We take this level of concordance as a primary factor in determining the location of zones of least gene flow. We hope to analyze other species in the future and to examine the degree of concordance in gene barriers between species to obtain a more accurate picture of the factors important in the zoogeography of Pakistan reptiles. Analysis of geographic variation in 13 morphotogical characters of Echis can'nams makes obvious a small number of underlying geographic patterns in this species within Pakistan. Most of the statistically significant differences in mean character values can be shown to exist in a limited number of sample pairs. These sample pairs and the number of characters that are significantly different between them are shown in Figure 24. It illustrates that of all the potentially interacting sample pairs, the greatest number of differences is between the Nushki-Quetta pair (7). It also shows that there is a north-south line representing many differences between adjacent east-west sample pairs from Shadatkot through Central Sindh to Rattankot, separating the Indus Valley populations from those of central and western Baluchistan. There are few significant differences between the various mainland Mekkran Coast samples. Nor are there many significant differences between samples in the remainder of central and northern Pakistan. However, NW Rajasthan is significantly different in a number of characters from all surrounding samples. Lastly, the Indus delta area is represented by a character complex in which almost all samples are significantly different from neighboring ones in one or more characteristics. A similar mozaic pattern of deltaic populations has been described from the mouth of the Mississippi River (U. S. A.) (Wilson 1970). In Pakistan the Indus Delta is the site of some species endemism among both the lizards and the turtles (Minton 1966). We presume that this mozaic of character state distributions in the Indus Delta was produced through repeated isolation of populations caused by dramatic changes in deltaic water distribution channels. The appearance, disappearance, and changing courses of distributaries in the Indus Delta during the past several hundred years are well documented (De Terra and Hutchinson 1936, see Flam 1986 for a recent review) and much older changes during the Quaternary are known for several sites in eastern Pakistan and adjacent India (Oldham 1886, Marshall 1931, De Terra and Patterson 1939, Erikkson 1959). We believe the isolation and reconnection of populations of Echis carinams in this area by changing distributary patterns are directly responsible for the mosaic pattern of character states seen in the delta area. Thus the major part of the between- sample differentiation in this area is believed to have a historic basis. The north-south line of differentiated populations paralleling the Sulaiman Range and its outliers also seems to have a largely historic basis, for environmental conditions are largely identical on both sides of the dividing zone (Fig. 25). We conclude that the populations on either side of the AUFFENBERG & REHMAN: THE GENUS ECHIS 301 1 /1 6 1 1 1 5~--3 -312. SL./11 3 1/ . 34 ~0 3 3 3 Figure 24. Numbers of statistically different character states between adjacent populations in Pakistan. 302 BULLEnN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) 60 64| 68| 72| 76~ 8 36 .,6„ s. s. DISPUTED AREA 5. 32 2 28 j 3 24 I Figure 25. General distribution of natural vegetation types in Pakistan (simplified, but based on Map 52, The Atlas of Pakistan, 1985, Rawalpindi, Pakistan). (1) Desertic; (2), Tropical thorn forests; (3) Tropical deciduous forests; (4) Temperate pine-juniper forests; (5) Subtropical dry pine forests; (6) Temperate dry pine forests; (7) Temperate broad-leafed forests; (8) Temperate pine/steppe (usually interspersed between mountain ranges in north, variously mixed with juniper in south). AUFFENBERG & REHMAN: THE GENUS ECHIS 303 mountains arrived there from different directions. Those west of the mountains are clearly closely related to Transcaspian and Iranian Plateau populations and must have arrived from the west and/or northwest. Those east of the mountains have been associated with the Indus Plain for thousands of years. The two populations are more or less genetically isolated by the high Sulaiman Range, the mountains having few passes at low elevations. However, a natural avenue leading from lowland arid lands in the Indus Plain to the arid lands of the Iranian Plateau occurs from near Jacobabad (and the Shadadkot sample) to Quetta across the Bolan Pass (1650 m). This pass is unquestionably a major path for genetic interchange between the Trans-Sulaiman population in northwestern Baluchistan and those of the central Indus Plains. Through appropriate similar habitat (Fig. 25) and climate, the Quetta population is also genetically closely related to those of the NWFP. Thus the fact that the Quetta sample is more closely related to those from Shadadkot (Indus Plain) and from NWFP than to the geographically much closer Nushki sample (Iranian Plateau) seems to be largely a matter of more rapid gene flow through similar habitats than across the borders of dissimilar ones. Apparently a more southern lowland gene pool and/or an eastern subtropical one of Echis (sochureki) was brought into close juxtaposition with a temperate plateau pool (multisquamatus). There is no evidence that the two populations are genetically incompatible, or that they are sympatric, i.e., forming the northern ends of a Rassenkreis around the Sulaiman Mountains and through the Bolan Pass. Rather, the two forms seem to blend evenly and completely into one another over a narrow zone of intergradation. The fact that the E. c. multisquamatus character complex is approached by populations in similar desert environments along the eastern borderland of Pakistan (Thar-Cholistan Desert) suggests substantial similarity in certain selective pressures, in spite of the fact that the northwestern deserts are temperate, and the eastern ones are tropical. While populations from this area are distinct from surrounding ones in several characters, the number and kind of differences suggest they are most closely related to those of the Indo- Gangetic Plain. The differentiation witnessed is probably based on factors associated with the Pleistocene local desertification of the area (Karpov and Nebolsine 1964, and others). The character differences exhibited between the Nushki-Quetta and NW Rajasthan-Multan populations reflect points along two ecoclines (sensu Auffenberg 1955), rather than geoclines, for environmental conditions on either side of the intermediate zones are significantly different (desert versus non-desert). Other ecoclines may include the change in characters between the population of northern and southern India, and from Nushki to the Mekkran Coast. Probably most significant are the series of clines between the Himalayan foothills (more mesic) to the central Indus Plain (more arid). The differences in the latter are along a north to south, cooler to warmer 304 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) environmental gradient. Among others, Edgren (1961), Smith (1956), and Christman (1980) have demonstrated the common existence of important north-south clines in the mean scale values of snakes, so that this particular series of clines in Echis is perhaps expected. However, other important clines in Pakistan Echis cannams are clearly east-west. The several character clines along the Mekkran Coast Coast are examples. While the Himalaya-Indus Plain changes are clearly ecoclines of some sort, those of the Mekkran Coast are not, for environmental conditions from the Iran border to at least the Hab River are very similar, yet changes in mean character states occur in a regular pattern. Fox et al. (1961) have shown a positive correlation between developmental temperature and meristic counts in snakes. Thus the developmental temperatures of embryonic snakes may be the mechanism maintaining the clines witnessed, but if so, the adaptive significance remains to be discovered. Possible Selective Forces In Echis carinatus some of the most important characters showing significant geographic variation are scales. Some of the clines demonstrated in Echis meristic characters are clearly ecoclines (sensu Auffenberg 1955), maintained by adaptation to environmental conditions that also vary clinally. A true geocline occurs in northern peninsular India. Within Pakistan, the patterns of variation in such characters as ventral scales are ecoclines on the basis of the fact that they are repeated at the ecotones between desert and non- desert environments at opposite ends of the country. Cherlin (1983b) suggested there is an important positive relationship between the mean number of body scales (longitudinal ventral rows and transverse dorsal rows) of Echis species and climate (mean relative humidity X average annual temperature/average annual daily range of air temperature). However, his formula has never been tested by analysis of meristic characters within a single species. Scrutiny of the isophenic maps of geographic variation in the scalation of Echis in Pakistan suggest that these patterns may indeed be correlated with climatic condition. Thus, higher scale counts and lighter colors are often associated with arid environments (particularly the Cholistan-Thar Desert [= NW Rajasthan sample, in part] and Chagai Desert [ = Nushki sample, in part]; see Fig. 25 for major vegetation zones in Pakistan; Table 5 relates our sample areas to these vegetative zones). We thus turn our attention to an analysis of these characters in reference to climatic factors. Spearman Rank Correlation values ( = Rs) and corrected z values were calculated for the relationship between a number of the more distinctive geographic patterns of meristic characters and certain climatic factors. The meristic characters selected were the mean number of dorsal spots, ventrals, AUFFENBERG & REHMAN: THE GENUS ECHIS 305 and gulars; the climatic factors were mean annual temperature, and the mean daily maximum and mean daily minimum temperatures for April, May, June and July (separately). These are the months when saw-scaled vipers are most active in Pakistan (Rehman, MS). We also obtained correlation for these important meristic characters and the Cherlin climatic "equitability' formula. Our results show there is no significant correlation between the mean number of ventral scales and Cherlins climatic value for the same geographic points (Rs 0.10, z 0.36). However, we found a significant negative correlation (p 0.02) between mean ventrals and mean annual rainfall at each sample site (Rs 0.35, z 1.22, p 0.02). Samples with low rainfall areas are not only arid, but hot in summer, and we believe that temperature is, in this instance, more important than precipitation (many desert areas in Pakistan fail to get rain for several successive years). The correlation between ventrals and mean annual daily maximum temperature is not significant (Rs 0.06, z 0.21, p < 5%). Nor is there a significant correlation between mean daily maximum temperatures and mean ventral number in April (0.22, z 0.45 respectively). However, the same correlations for June (0.33, 1.15) and July (0.32, 1.12) are both barely significant at the five percent level. For May, the correlation shows a higher significant value (0.53,1.84, p < 4%). In general, the mean daily minimum temperatures shows a similar range of from poor to fair correlations with mean ventral number (May Rs 0.43, z 1.46, June Rs 0.18, z 0.64). July daily minimum temperatures shows the best correlation of all (Rs 0.63, z 2.18, p < 0.05). These minimum temperatures occur during the night, when most individuals forage (Rehman, MS). The number of dorsal blotches also show a geographic pattern significantly correlated with the mean number of ventral scales (Rs 0.79, z 3.96, p < 0.02), but a consistently low correlation with mean daily maxima or minima. Nor is there a good correlation between any climatic factor and the mean number of gulars. Thus of all the significant geographic patterns in meristic characters, ventral scales appear to show the best correlation with climatic factors. Figure 26 provides data on the distributional pattern of mean summer high temperatures. It shows that within the Pakistan area the highest mean summer highs are achieved in western Baluchistan and NW Rajasthan--exactly those areas in which most of the mean scale counts are highest. Within the range of Echis carinatus in Pakistan, the mean daily minimum summer temperatures occur in areas of deciduous and mixed, rather than thorn brush habitats (Table 5, Fig. 26). These areas also tend to have proportionately lower scale counts. The same pattern can be demonstrated in dorsal and ventral color density, for the colors are least intense in desert areas and most intense in forested areas (a typical, world-wide pattern). In the Indian peninsula, Echis carinatus from the relatively cooler (Fig. 26), more moist and 306 BULLEHN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) V 1 0 45 40 r- .j 0 46 45 o 35 40 Figure 26. Mean high summer temperatures in the Indian Subcontinent (modified from Atlas of Pakistan 1986 and Koteswarum 1974). AUFFENBERG & REHMAN: THE GENUS ECHIS 307 more heavily forested Goa-Kerala area are significantly darker and with fewer scales than those populations in the remainder of the peninsula. In his study of the effects of temperature on the scalation of Echis species, Cherlin (1983b) developed what he termed a "dorsal scale index." It is determined by multiplying the number of ventrals by the number of middorsal scale rows. This is a very useful statistic, for it provides a comparative statement of the relative number of scales covering the back. From a physiological standpoint it is useful in providing an index of the amount of skin between the scales, for this is where water loss occurs, and thus evaporation takes place. Snakes with more scales have proportionately more skin exposed per body surface. The more evaporation the greater potential for lowering high body temperatures during near-lethal limits at the high end. The physiological basis of the importance of Cherlin's index has not yet been unquestionably demonstrated. However, when we plot the values geographically we find that the geographic pattern of mean values follows the common one shown previously for ventral and dorsal scales; i.e., highest values in northwestern Baluchistan (Chagai Desert) and northwestern Rajasthan and adjacent Pakistan (Cholistan-Thar Desert), the lowest in NWFP and along the foothills of the Himalayas. Statistically significant differences in the means of adjacent populations occur between Nushki-Quetta, Karachi-Kirthar, Multan- NW Rajasthan, Lahore-NW Rajasthan, and Rajasthan-NW Rajasthan samples. There is no statistical correlation between Cherlin's scale index and mean daily maximum summer temperatures (R2 0.01), or the scale index and mean minimum summer temperatures (Rz 0.03). While critical thermal maximum value has not yet been determined for Echis carinatus, we presume it is close to 40°C, as such values are for most snakes (Lillywhite 1987), regardless of their environmental preferences (Spellerberg 1972). Thus, during the hottest seasons of the year it is only at night when temperatures are sufficiently reduced to allow active foraging on the surface (30-37°C Rehman, MS). It follows that the daytime highs are probably the most critical during the hot seasons, and though the snakes are then usually in abandoned rodent burrows (Rehman MS), daytime burrow temperatures sometime exceed 35°C in arid parts of Pakistan (Auffenberg MS). Brown (1957) defines centrifugal speciation as that process by which populations central to the point of speciation for that subspecies evolve much faster than peripheral populations. Thus the most distant populations receive adaptive genes more slowly, determined by the rate of gene flow in that direction. The more distant a population, the more time it will take for an evolutionary change to reach it . Populations completely isolated (such as Echis cannams astolae, on an island) may never acquire newer adaptations, and thus remain "primitive" with respect to those adaptations. We believe this 308 BULLEnN FLORIDA MUSEUM NATURAL HITI'ORY VOL. 35(5) hypothesis best explains most of the kind and degree of geographic variation witnessed in this study. Our studies on Echis populations in the Indo-Pakistani area suggest there are five recognizable major adaptive centers. These are Transcaspia, Iranian (out of our main area of study), Astola Island (minor), Indo-Gangetic Plain, Himalayan foothills, and Cholistan-Thar Desert. We believe that the gene flow from these four adaptive areas account for most of the geographic patterns seen in the characters we studied. The only other factor considered important is the pattern mosaic in the Indus Delta, which is believed due to distributory shifts during the PIeistocene and possibly Post-Pleistocene. LITERATURE CITED Auffenberg, Walter. MS. Behavioral Ecology of the Bengal Monitor. Beg, A. R. 1983. Wildlife habitats of Pakistan. Pakistan Forest Inst., Peshawar. 56 pp. Brown, W. L. 1957. Centrifugal speciation. Quart. Rev. Biol. 32:247-77. Cherlin, V. A. 1981. [The new saw-scaled viper Echis multisquamatus sp. nov. from southwestern and middle Asia]. Proc. 7001. Inst. Acad. Sci. USSR 101:92-5. (in Russian). . 1983a. [New data on taxonomy of snakes of the Echis genus]. Vesnik Zool. 1983:42-6. (in Russian). . 1983b. [Dependence of scale pattern in snakes of the genus Echis from climatic factors]. Zoologicheskii Zh. 62:252-8. (in Russian). Christman, S. P. 1980. Patterns of geographic variation in Florida snakes. Bull. Florida State Mus., Biol. Sci. 25(3):157-256. Constable, J. D. 1949. Reptiles from the Indian peninsula in the Museum of Comparative Zoology. Bull. Mus. Comp. Zoot. 103:59-160. De Tem, H., and G. E. Hutchinson. 1936. Data on Post-glacial climatic changes in northwestern India. Curr. Sci. 5:5-10. , and T. T. Patterson. 1939. Studies on the Ice Age in India and associated human cultures. Carnegie Inst. Publ (493):1-115. Edgren, R A. 1961. A simplified method for analysis of clines; geographic variation in the hognose snake, Heterodon plao,hinos Latreille. Copeia 1961 (2):125-32. Erikkson, K G. 1959. Studies of the dry bed of the River Ghaggar at Rang Mahal, Rajasthan, India. Acta Archeol. Lundensia, ser. 4 (3):1-63. Flam, L. 1986. The Indus River and the Arab Period in Sindh. Sindhological Stud. Inst. Sindhology, Univ. Sindh, Jamshoro Summer 1986:5-13. Geoffroy, Saint Hillaire, E. 1827. Description de VEgypte. Histoire naturene, Reptilia Paris. 344 P. Khan, M. S. 1980. Affinities and zoogeography of herptiles of Pakistan. Biologia 26(1/2):113- 171. Koteswarum, P. Research in the humid tropical Asia. 12th National Congress UNESCO. pp. 1- 30. Lillywhite, H. B. 1987. Temperature, energetics, and physiological ecology. Pp. 422-477 in k A. Seigel, J. T. Collins, and S. S. Novak (eds.). Snakes: Ecology and Evolutionary Biology. MacMillan Co., New York. 529 p. Marshall, J. 1931. Mohenjo-daro and the Indus Valley Civilization. MacMillan Co., London. 244 p. Mertens, R 1969. Die Amphibien und Reptilien West-Pakistans. Stuttgarter Beitr. z. Naturkunde (197):1-96. Oldham, R. D. 1886. On probable changes in the geography of the Punjab and its rivers. J. Asiat. Soc. Bengal (55):322-43. AUFFENBERG & REHMAN: THE GENUSECHIS 309 Schneider, J. G. 1801. In B. G. E. Lacepede, Naturgeschichte der Amphibien. Vol. 4,:156-256. J. M. Bechstein, Weimar. Smith, P. W. 1956. A blotch-count gradient in snakes. Herpetologica 12(3):156-60. Spellerberg, I. F. 1972. Temperature tolerances of southeast Australian reptiles examined in relation to reptile thermoregulatory behavior and distribution. Oecologia 9:23-46. Stemmler, 0. 1969. Die Sandrasselotter aus Pakistan: Echis carinatus sochureki subsp. nov. Aquaterra 6:118-24. Wilson, L. D. 1970. The racer Coluber constrictor (Serpentes: Colubridae) in Louisiana and eastern Texas. Texas J. Sci. 22(1):67-85. TABLES Table 1. Geographic variation in number of mean ventral scales in those adjacent populations (Pakistan and border sites) showing significant differences in their means. Sample Pairs Ventrals di. P. Afghanistan-Quetta 181-165 22 < 0.001 Quetta-Nushki 165-183 22 < 0.001 Thar Parkar-Gujarat 158-162 27 < 0.01 Thar Parkar-Nagar Parkar 158-168 25 < 0.01 Multan-NW Rajasthan 165-181 10 < 0.03 Lahore-NW Rajasthan 162-181 8 < 0.05 NW Rajasthan-Rajasthan 181-158 14 < 0.01 * df, degrees of freedom; p, probability on basis of Student's t-test. 310 BULLEITN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) Table 2. Variation in ventral and subcaudal scales among siblings in single broods of Pakistan and Indian Echis. Ventrals Subcaudals Locality (N) OR* Mean SD* OR* Mean SD* Goa, India (4) 140-143 142.2 1.7 24-26 25.3 1.0 Kerala, India (3) 149-152 150.3 1.3 29-30 29.7 0.6 Thar Parkar, Pakistan (7) 154-160 157.0 1.9 25-27 26.3 1.0 Thar Parkar, Pakistan (12) 154-162 158.6 2.6 23-30 26.4 2.5 Karachi, Pakistan (12) 159-173 164.8 4.7 27-35 29.1 2.1 Shadadkot, Pakistan GO) 162-177 169.6 5.0 26-36 29.4 2.4 Quetta, Pakistan (8)) 162-171 165.7 3.1 24-34 28.4 3.7 * OR, Overall range; SD, standard deviation. Table 3. Geographic variation in number of dorsal spots in those adjacent populations (Pakistan and border sites) showing significant differences in their means (p < 0.5) (abbreviations as in Table 1) Sample Means df p Nushki-Quetta 39-35 22 < 0.001 Quetta-Shadadkot 35-31 19 < 0.1 Karachi-Ratan kot 36-31 31 < 0.001 Karachi-Mekkran Coast 36-38 29 < 0.25 Shah Bundar-Thatta 37-33 302 < 0.01 Shah Bundar-Thar Parkar 37-40 33 < 0.1 Shah Bundar-Gujarat 37-33 27 < 0.1 Thar Parkar-Thatta 40-33 310 < 0.1 Thar Parkar-Gujarat 40-32 27 < 0.01 Thar Parkar-Central Sindh 40-32 22 < 0.1 Thar Parkar-Rajasthan 40-33 15 < 0.5 NW Rajasthan-Lahore 41-31 8 < 0.1 NW Rajasthan-Multan 41-34 11 < 0.1 AW Rajasthan-Central Sindh 41-32 12 < 0.1 AUFFENBERG & REHMAN: THE GENUSECHIS 311 Table 4. Geographic variation in degree of darkness of ventral spots in those adjacent populati6ns (Pakistan and border sites) showing significant differedces in their means (p < 0.5) (abbreviations as in Table 1). Sample Means df p Nushki-Quetta 1.4-0.9 22 < 0.001 Karachi-Mekkran Coast 2.6-1.5 28 < 0.001 Shadatkot-Cent. Sindh 0.7-2.0 15 < 0.010 Lahore-NW Rajasthan 2.0-0.3 8 < 0.050 NW Rajasthan-Cent. Sindh 0.3-2.0 11 < 0.050 Rajasthan-Thar Parkar 1.0-1.9 27 < 0.025 Thar Parkar-Nagar Parkar 1.9-1.0 23 < 0.025 Gujarat-Nagar Parkar 1.8-1.0 22 < 0.010 Karachi-Kirthar 2.6-1.3 32 < 0.010 Table 5. Echis sample areas and the general vegetative zones in which each is located. Sample Area Zone Sample Area Zone Multan Thorn Brush Islamabad Subtrop. Pine Cent. Sindh Thorn Brush Lahore Trop. Decid. Thar Parkar Thorn Brush NWFP Trop./Subtr. Pine Thatta Thorn Brush Quetta Temp. Jun./Pine Karachi Thorn Brush Nagar Pakar Trop. Decid. Ghost Thorn Brush Zabol Temp. Desert Mekkran Coast Thorn Brush* Afghanistan Temp. Desert Panjgur Thorn Brush Nushki Temp. Desert Rattankot Thorn Brush NW Rajasthan Trop. Desert Shah Bundar Thorn Brush Shadadkot Trop. Desert Rajasthan Thorn Brush Gujarat Thorn Brush Parachinar** Temp. Pine * Mekkran Coast thorn brush is rather different from that of the remaining Indus Valley types (see Beg 1983 for review). " Included in NWFP throughout this publication, but separated here because Echis carinams from Parachinar are very dark. 312 BULLEnN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) APPENDIX I Locality data and present museum location for specimens examined during this study. Locality Museum nr. Abadan, Iran SMF Ajmere, Rajasthan, India ZSI Allahabad, Gujarat, Iran ZSI Amballa (100 mi. S), India ZFMK, MCZ Aram, Fars, Iran FMNH Aschabad, Turkmen SSR SMF Astola Isl., Baluchistan, Pakistan SMF Badin, Sindh, Pakistan ZSD Balchany, Transcaspia SSR ZIN Bampur, Iran SMF Barnrud, Iran ZIN? Bangalore, Karnataka, India ZSI Bhavnagar, Gujarat, India BNHS Bhit Poochari, (Punjab ?), Pakistan RSM Bombay, Maharashtra, India BNHS Bushire, Iran ZSI nr. Cancona, Goa, India ZSI Cape Monze, Sindh, Pakistan RSM Chabar, Persian Gulf, Iran BNHS Chumbum, Tamil Nadu, India BNHS Colombo, Sri Lanka SMF Deesa, Gujarat. India BNHS Dem Ismail Khan, NWFP, Pakistan BNHS Dhabiji, Sindh, Pakistan ZSD Dir, NWFP, Pakistan PMNH Dureji, Baluchistan, Pakistan RSM Durun, Transcaspia SSR ZIN? Duschak, Transcaspia SSR SMF Fars, Iran CAS Fatehjang, Punjab, Pakistan PMNH Ft. Sandeman, Zhob, NWFP, Pakistan BNHS Goa, India UF Gondal. Gujarat, India BNHS Gosht, 42 mi. N Dizak, Seistan, Iran ZSI, BNHS Gumtur Dist., A. P., India ZSI Gurshir, Iran ZIN? Hab Chouki, Baluchistan, Pakistan AMNH, RSM Henjam Isl., Persian Gulf, Iran BNHS Hinadan crossing, Baluchistan, Pakistan AMNH Hingol Natl. Park, Baluchistan, Pakistan UF Hingolgadh, Gujarat, India BNHS Hungo, Kohat, NWFP, Pakistan UF, ZSD Hyderabad, Sindh, Pakistan AMNH Islamabad UMMZ, PMNH Jabalpur, Madha Pradesh, India ZSI AUFFENBERG & REHMAN: THE GENUS ECHIS 313 Locality Museum Jaisalmere, Rajasthan, India ZSI Jamsanda (nr. Bombay) Maharashtra, India USNM Jask, Persian Gult Iran BNHS Jati, Sindh, Pakistan RSM Jiwani, Baluchistan, Pakistan SMF Jhang, Punjab, Pakistan UMMZ Jungshai, Sindh, Pakistan RSM Kacha, Baluchistan, Pakistan BNHS Kalagan, Baluchistan, Pakistan ZSI Kalicut, Kerala, India BNHS Kanpur, U. P., India FMNH, USNM Karachi Dist., Sindh, Pakistan SMF, ZSD, NMW, UF between Karman amd Shiraz, Iran ZSI Kaur, Baluchistan, Pakistan BNHS, BMNH Kaweit, Iran BNHS Kerman, Iran ZIN? Kerula, Punjab, India FMNH, MCZ Khandahar, Afghanistan ZFMK 100 mi SW Khandahar, Afghanistan CAS Khandala, Afghanistan FMNH Khar Centre, Sindh, Pakistan UF Khokhrapur, Baluchistan, Pakistan SMF Khudsil Khan (nr. Quetta), Baluchistan, Pakistan ZSD Khuzistan, Iran NMBA Killi Mangal, Baluchistan, Pakistan SMF Killi Jamaldini, Baluchistan, Pakistan SMF Kirthar Nati. Park, Sindh, Pakistan ZSD Kojdar, Mekkran Coast, Iran BNHS Krasnowodki, Transcaspia SSR USNM Lai Suharna Natl. Park, Punjab, Pakistan UF Larkana, Sindh, Pakistan BNHS, UF Madras, Tamil Nadu, India BNHS, MCZ Makli, Sindh, Pakistan ZSD, UF Mand, Baluchistan, Pakistan BNHS nr. Manjhand, Sindh, Pakistan AMNH Mango Pir, Sindh, Pakistan ZSD Matiari (nr. Hyderabad), Sindh, Pakistan ZSD Mednapur, West Bengal, India FMNH, MCZ Megas, E Iran ZIN Mekkran Dist., Baluchistan, Pakistan BNHS Miranshah, NWFP, Pakistan BNHS Mithi, Sindh, Pakistan SMF Mohen-jo-daro, Sindh, Pakistan SMF Multan, Punjab, Pakistan ZSD, UF Munbhum Dist., Bihar, India ZSI Nabisar Nota, Sindh, Pakistan RSM Nagaur Dist., Rajasthan, Pakistan ZSI Nasrie, Iran ZIN Nazirabad, Iran BNHS Nellore Dist., Andra Pradesh, India BNHS Nushki, Baluchistan, Pakistan SMF, RSM Panjgur, Baluchistan, Pakistan SMF, ZSM Patho Pass (Pab Hills), Baluchistan, Pakistan RSM 314 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 35(5) Locality Museum Persepolis, Iran FMNH Peshawar, NWFP, Pakistan UF, ZSD Point Calimere, Tamil Nadu, India BNHS Pot-Absinch, Fars, Iran FMNH Poona, Maharashtra, India ZSI Pugal, Rajasthan, India ZSI Puttur (Chittor) Andra Pradesh, India USNM Quetta, Baluchistan, Pakistan SMF, ZSD, RSM Quilon, Kerala, India AMNH, UF Ratan Kot, Sindh, Pakistan SMF Saman (Dasht Dist.), Baluchistan, Pakistan ZSI Sehirabad, (nr. Buchara, Afghanistan ?) ZIN Schechradj, Baluchistan, Pakistan ZMFK Shah Bundar. Sindh, Pakistan CAS Shadadkot, Sindh, Pakistan SMF Soman Dist., Baluchistan, Pakistan ZSI Spinkaras, Baluchistan, Pakistan SMF Sirohi, Rajasthan, India ZSI nr. Stalinabad, Uzbekistan SSR NMBA Thar Parkar, Sindh, Pakistan SMF Thatta, Sindh, Pakistan UF, ZSD, AMNH, SMF, RSM Trivandrum, Kerala, India UF, UMMZ Turkmen SSR SMF, ZMFK nr. Urak, Baluchistan, Pakistan SMF Valpoi, Goa, India ZSI nr. Zabol, Iran SMF, FMNH Zhor, Sindh, Pakistan ZSD , nr. Zirkuch, E. Iran ZIN? Contributions to the BULLEI'IN OF THE FLORIDA MUSEUM OF NATURAL HISTORY, BIOLOGICAL SCIENCES, may be in any field of biology. Manuscripts dealing with natural history or systematic problems involving the southeastern United States or the New World tropics are solicited especially. Manuscripts should be·of medium length-circa 35 to 200 pages (10,500-60,000 words). Examination for suitability is made by an Editorial Board. 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