BULLETIN OF THE FLORIDA STATE MUSEUM BIOLOGICAL SCIENCES Volume 3 Number 4 STUDIES ON FISHES OF THE FAMILY CHARACIDAE NO. 16.-A NEW HYPHESSOBRYCON FROM COSTA RICA James E. Bahlke \/853 UNIVERSITY OF FLORIDA Gainesville 1958 The numbers of THE BULLETIN OF THE FLORIDA STATE MUSEUM, BIOLOGICAL SCIENCES, will be published at irregular intervals. Volumes will contain about 800 pages and will not necessarily be completed in any one calendar year. WILLIAM J. RIEMER, Editor ROLAND F. HUSSEY, Associate Editor All communications concerning purchase or exchange of the publication should be addressed to the Curator of Biological Sciences, Florida State Museum, Seagle Building, Gainesville, Florida. Manuscripts should be sent to the Editor of the BULLETIN, Flint Hall, Universityof Florida, Gainesville, Florida. Published 10 November 1958 Price for this issue $.14 STUDIES, ON FISHES OF THE FAMILY CHARACIDAE. NO . 16.-A NEW HYPHESSOBRYCON FROM COSTA RICA JAMES E. BOHLKE 1 SYNOPSIS: A new tetra of the genus Hyphessobrucon is described from the Tortuguero River in Costa Rica. While it is thought to be really close to none of the other known members of the genus, H!/Phessobr!/con comptessus (Meek) and H. milleri Durbin are probably its closest allies. The species is also compared with the rhoadsiine, Rhoadsia eigenmanni (Meek), from near the same geographic locality. The characid described as new in this paper is part of a collection of fishes recently made under the direction of A. F. Carr in Costa * Rica, while Carr, as Principal Investigator, was engaged on National Science Foundation Project G-1684 (The Ecology and Migrations of Sea Turtles). David K. Caldwell is studying the greater portion of the fishes collected, but the characids were sent t6 me for determina- tion. I wish to thank Caldwell for supplying me with the field data f6r the collection that included the new species. Tortuguero, the place where the. fish were collected, is located on the northeastern coast of C6sta Rica a short distance from the Nicaraguan border. The fbllowing abbreviations are used in the text: UF (Uniyersity of Florida Collections), ANSP (Academy of Natural Sciences of Phila- delphia), CNHM (Chicago Natural History Museum). Hyphessobrycon tortuguerae new species HoLoTypE.-UF 5741, an adult male, 89.0 mm. in standard length, collected by L. H. Ogren from the Tortuguero River (Lagoon) at Tor- tuguero, 2 miles from ocean inlet, Costa Rica; collected by cast net near a submerged brush pile and on an incoming tide; slight current, but collection from a sheltered area; depth of 842 feet, but dropping sharply to 20 or 25 feet; bottom of sandy muck; water brackish due to strong outflow of fresh water from river; water of light tea color; , vegetation of water hyacinths only; collected 3 September 1956. Orig- inal field number 157. i James B6hlke is Associate Curator of the Department of Ichthyology and Herpetology at the Academy of Natural Sciences of Philadelphia. This. study was carried out while the writer was serving as Collaborator on the staff of the Florida State Museum. Manuscript submitted 25 April 1958.-ED. 174 BULLETIN FLORIDA STATE MUSEUM Vol. 8 PARATypEs.-UF 5886, 8, 24.2 to 24.8 min., ANSP 80986, 2, 26.8 and 27.5 min., ANSP 80987, 1 stained specimen. 27.5 mm.; all col- lected with the holotype. DIAGNOSIS.-Maxillary teeth rather numerous, 9 or 10; lateral scales 85 or 86; two humeral spots, but no dorsal, caudal, or anal blotches; 6 teeth in the inner premaxillary series. DESCRIPTION.-Because of the great difference in size between the holotype and paratypes, the following description is of the holotype only. A statement of the obvious deviations from this description shown by the paratypes is presented later. Proportions and counts for the holotype and four paratypes are presented in table 1. Figure 1.-Holotype of Hyphessobrucon tortuguerae, UF 5741, 89.0 mm. Photograph by A. Delwin Warden. Hyphessobrucon tortuguerae (fig . 1 ) is one of the deep-bodied , greatly compressed species of the genus. The body is deepest at the origin of the dorsal; the depth at this point goes 2.7 times in the standard length. The caudal peduncle is slender and short, its length little greater than its least depth-least depth goes 9.5 times, and length goes 8.0 times, iii the standard length. Length of head goes 3.4 times into standard length. Eye diameter goes 2.7, snout length 4.1, bony interorbital width 3.9, and length of upper jaw 2.6 times into head length. The eye does not enter the dorsal profile; its diameter is much greater than the length of the snout. The snout is slightly, but constantly, shorter than the inter- orbital width. The maxillary extends back beyond the front margin of the eye, but not to a vertical with the fore margin of the pupil. The mouth is terminal; the lower jaw protrudes. 1958 BOHLKE: FAMILY CHARACIDAE 175 Fontanels are moderately developed and completely separate frontal end parietal bones except for a strong bridge between them. The lateral margins of both fontanels are straight lines; their widths taper evenly from the widest point at the base of the occipital process to the anterior ends of the frontal bones. The great suborbital does not nearly cover the cheek and leaves broad free areas both below and behind. Three postorbitals are present; all leave rather broad, naked areas free behind them. Gill rakers are long-the longest about equal to the pupil-slender, close-set; there are 9+17 on the first gill arch. Teeth are essentially tricuspid on all jaw bones. Some of the smaller ones on the premaxillary and the posterior parts of the maxillaries and mandibles lack lateral shoulders and are conical. ' Premaxillary teeth on one side (the other side is injured) are in two series, with three in' the outer row, six in the inner. There are 9 or 10 teeth along more than half the free edge of the maxillary. On the mandibles there are five large teeth in, front, followed by six abruptly smaller teeth along the sides. The maxillary ends postero- dorsally in a rounded point. The origin of the dofs al fin is equidistant from the tip of the snout and the base of the caudal; its distance from the tip of snout goes 1.9 times into standard lehgth. The dorsal origin is distinctly in advance of that of- the anal; a Vertical with the base of the first anal ray falls slightly behind the mid-point of the dorsal base. The dorsal Bn is pointed, its posterior margin nearly a straight line; the height of the fin goes 3.3 times in the standard length. The adipose dorsal fin is :well developed, its origin is above the nineteenth 61- twentieth branched anal ray. The pectoral and ventral Rns are pointed; the former overlaps the latter, the latter overlaps the anal fin. The length of the pectoral goes 5.0, the length of the ventral 5.3, the snout to pectoral distance 8.7, the snout to ventral distance 2.3, and the snout to anal distance 1.7 times into the standard length. The anal fin is lobed anteriorly; the margin of the fin just behind the lobe is concave. The final un- branched and first Bve branched anal rays have tiny hooks; this is a male secondary sexual characteristic. The caudal Bn is deeply forked; the lobes are slender and rounded. The scales are cycloid, with few concentric ridges, and rather many radii on their exposed portions (4 to 7 radii counted on each of a small sample of scales -from below the dorsal En above midbody). Lateral scales number 86, of which 8 or 9 are perforated. Transverse scales between dorsal and ventral fins number ?14 (the count is uncer- 176 BULLETIN FLORIDA STATE MUSEUM Vol. 8 tain because of missing scales), and, scales around the caudal peduncle number 14. The predorsal line is scaled. The caudal fin is scaleless, except at its base. COLORATION IN ALCOHOL.-The body, head, and fins are everywhere rather heavily sprinkled with melanophores. There ii no lateral band save for the usual, Bne, deep-lying line of intermuscular meland- phores. There is no caudal spot, nor are bands or spots present on dorsal, pectoral, ventral, or caudal fins. A broad dark band is present down the center of the anal fin, the Bn being lighter both proximally and distally. The top of the head and upper half of the postorbital part of the head are dark. There are two dark hurneral spots with a lighter area between them; the anterior is narrow, vertically elongate, and crosses the second to Rfth scales of the lateral line. The posterior humeral spot is more roundish, considerably more intense than the other, and is placed above the seventh to ninth scales of the lateral line. VARIATION IN 'THE PARATYPES,-GreateSt depth of body goes 8.1 to 8.5,-least depth of peduncle 9.8 to 10.7, length of peduncle 7.4 to 7.9, length of head 8,8 to 3,4, tip of snout to origin of dorsal fin 1.9 to 2.0, snout to pectoral 8.4, snout to ventral 2.2 to 2.3, snout to anal 1.7, height of dorsal, fin 8.1 to 8.2, length of ventral fin 4.8 to 5.1, and length of pectoral fin 5.0 to 5.6 times into the standard length. * Diameter of eye goes 2.5 to 2.6, length of snout 4.0 to 4.3, least width of bony interorbital 3.5 to 8.7, and length of upper jaw 2.5 to 2.7 times into length of head. Fin ray and gill raker counts are summarized in table 2. Lateral scales number 85 Or 36, of which 7 to 10 are perforated (I count 8 each of 7,8, and 9 scales, and 1 of 10 scales). Outer premaxillary teeth number 2 to 4 (2 counts of 2 teeth, 5 of 8 teeth, and 1 of 4 teeth). Inner premaxillary teeth number 6 or 7 (one uncertain count of 7). There ate 4 or 5 enlarged anterior mandibular teeth in front of the tiny lateral teeth. The stained 27.5 mm. specimen has 10 and 9 maxillary teeth, and three postofbitals on each side, Coloration of the small paratypes is in general similar to that of the holotype, but the anterior humeral spot is darker so that the two spots are of about equal intensity. The longitudinal dark stripe on the anal fin is variously developed but is always apparent on .the paratypes. RELATIONSHIPS.-The species may be distinguished from all other. known members of the genus by the combination of characters given in the diagnosis. It appears t6 be more closely related to Hyphes- 1958 BOHLKE: FAMILY CHARACIDAE 177 TABLE 1. HE/phessobrt/Con tortuguerae: PROPORTIONS (AS THOUSANDTHS OF STANDARD LENGTH) AND FIN RAY COUNTS OF THE HOLOTYPE AND FOUR PARATYPES ANSP UF 5886 80987 UF 5741 (lof 3) ANSP 80986 stained holotype Standard length (mm.) 24.2 26.8 27.5 27.5 89.0 Greatest depth 810 284 316 820 872 Shoot to dorsal 588 511 527 524 . 526 Snout to pectoral 298 295 291 291 278 Snout to ventral 455 440 444 444 481 Snout to anal 599 580 587 585 585 Depth of peduncle 101 098 102 102 105 Length of peduncle 126 184 129 127 - 124 Length of pectoral 186 179 198 200 200 Length of ventral 207 198 200 207 190 Height of dorsal 322 - 809 809 299 Length of head 298 800 295 296 291 Diameter of eye 116 119 116 116 108 Length of snout 074 075 078 069 071 Bony interorbital 085 082 082 085 074 Length upper jaw 120 112 120 120 110 Dorsal rays 49 ii,9 ii,9 ii,9 ii,9 Anal rays , v,25 v,25 v,24 v,24 v,26 Pectoral rays (left and right) i,12 i,18 i,12/i,18 i,18 i,12 Ventral rays (left and tight) i,7 j,8 i,8 i,7 i,8 Caudal rays i,17,i i,17,i i,17,i i,17,i i,17,i TABLE 2 Hyphessobrimon tortUgUerae: FIN RAY AND GILL RAKER COUNTS OF THE'SEVEN TYPE SPECIMENS Rays Frequ6ncy Rakers Frequency Dorsal ii,9 ' 7 Upper limb 9 Anal v,24 2 10 v,25 8 Lower limb 17 v,26 2 18 0110, 1% el 01 co 07 Pectorals i,12 7 Total count 26 i,18 7 27 Ventrals i,7 8 28 i,8 6 Caudal i,17,i 7 178 BULLETIN FLORIDA STATE MUSEUM Vol. 8 sobrycon compressus (Meek) of Mexico and H. milleri Durbin of Guatemala than to others in spite of its lower lateral scale count, different coloration, and different gill raker counts. H. tortuguerae seems to be really close to none of the opher species, Because of the changes in dentition that rhoadsiine characids un- dergo during ontogeny, the new species was also compared with mate- rial of Rhoadsia eigenmanni (Meek) from Costa Rica. Loren P. Woods kindly lent me the following material of that species: CNHM 43i50, 1, 56.7 mm. in standard length; La Junta, Costa Rica; collected by S. E. Meek; 8 April 1912; CNHM 7861, 8, 47.0 to 54.6 mm., same locality and collector, 17 April 1918. Rhoadsia eigenmanni is easily distinguished from the new Hyphessobrucon by its multicuspid premaxillary, man- dibillar, and upper maxillary teeth; the presence of only a single, poste- rior, humeral spot; the presence of a well-defined, horizontally elon- gate, caudal blotch; more numerous anal fin rays (iii or iv, 26 to 80 contrasted with v, 24 to 26); and more numerous scales (87 to 41 con- trasted with 85 or 36). Myers (in Eigenmann and Myers, 1929, p. 468) appended a foot- note to the discussion of Rhoadsia eigenmanni, saying: "This species is Very likely generically distinct from Rhoadsia, in which case it would go by the name Carlia eigenmanni." Aside from the different color pattern which marks R. eigenmanni as a very distinctive form, the Costa Rican rhoadsiine appears not greatly different from -those of western Ecuador. It seems that all might well be maintained in the genus Rhoadsia. I wish to thank the following members of the staff of the Florida ~ State Museum for their aid in making this study possible: Arnold , Grobman, Director, and J. C. Dickinson, Jr., Curator of Biological Sciences, who financed and helped expedite the work; Daniel M. Cohen, curator of fishes, and John C. Briggs, Associate in ichthyology, who aided me greatly with the collections, library, and various other types of assistance during my stay in Gainesville. LITERATURE CITED Eigenmann, Carl H., and George S. 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