Int. J. Aquat. Biol. (2015) 3(1): 1-13 E-ISSN: 2322-5270; P-ISSN: 2383-0956 Journal homepage: www.ij-aquaticbiology.com © 2015 Iranian Society of Ichthyology Original Article Rotifer assemblages (Rotifera: Eurotatoria) of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India Bhushan Kumar Sharma*,1Sumita Sharma, Mrinal Kumar Hatimuria Freshwater Biology Laboratory, Department of Zoology, North-Eastern Hill University, Umshing, Shillong - 793 022, Meghalaya, India. Article history: Received 24 October 2014 Accepted 2 December 2014 Available online 25 February 2015 Keywords: Beels Composition Interesting taxa New records Richness Similarities Abstract: Our plankton and semi-plankton collections from twelve floodplain lakes (beels) of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families); these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI) and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region. Eleven species are new to the study area and we provide an updated list (144 species) for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub) tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12) species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index), more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters. Introduction Segers et al. (1993) hypothesized (sub) tropical floodplain lakes to be the globally rich habitats for rotifer diversity. This hypothesis is extended to the rotifer assemblages of the floodplain lakes (beels) of Assam (Sharma, 2005; Sharma and Sharma, 2005a, 2008, 2012a, 2014a) and pats of Manipur (Sharma, 2009a, 2009b) states of NEI. Various ad-hoc works and incomplete inventories from other Indian floodplains, however, do not facilitate any generalization. The present study is an attempt to analyze this salient feature as well as to examine ecosystem diversity of Rotifera in twelve beels of Majuli (commonly called ‘Majoli’ or land in the middle of two parallel rivers) - a geographically interesting landform of fluvial geomorphology of the Brahmaputra river system in Assam state of NEI. * Corresponding author: B. K. Sharma E-mail address: profbksharma@gmail.com This largest river island, the world-heritage site and hotspot for flora and fauna is alarmingly shrinking due to erosion and is threatened to cease existence on the world map. We present an inventory of the examined rotifer species with comments on richness, composition, interesting elements, community similarities and influence of abiotic parameters. This report is of biodiversity and ecology value besides providing an update for following meta-analyses on the rotifer diversity of Majuli studied earlier vide Sharma (2014). Materials and Methods Our observations are based on water and plankton and semi-plankton samples collected, during September, 2010-August, 2012, from twelve floodplain lakes (beels) of Majuli River Island 2 Int. J. Aquat. Biol. (2015) 3(1): 1-13 (Long.: 93°95'E, Lat.: 25°27'N), upper Assam (Fig. 1, Table 1). The sampled beels possessed different aquatic macrophytes’ namely Eichhornia crassipes, Hydrilla verticellata, Utricularia flexuosa, Trapa natans, Lemna major, L. minor, Pistia striates, Salvinia sp., Nymphaea spp., Nymphoides spp., Potamageton spp., Azolla pinnata, Euryale ferox, and Sagittaria sp. The collections were obtained monthly from six beels (marked with*) and seasonally from rest of the beels (Table 1). Water samples were examined for abiotic parameters. Water temperature, specific conductivity and pH were recorded by the field probes; dissolved oxygen was estimated by Winkler’s method while free CO2, total alkalinity and total hardness were analyzed following APHA (1992). The qualitative plankton samples were collected by towing a plankton net (# 50 µm) from the littoral, limnetic/semi-limnetic regions of different beels and were preserved in 5% formalin. All samples were screened with WILD (M8) dissecting microscope, different rotifers were isolated and mounted in polyvinyl alcohol- lactophenol mixture, and micro-photographs were taken with Leica (DM 1000) stereoscopic phase contrast microscope fitted with an image analyzer. The different species were identified following Koste (1978), Segers (1995) and Sharma and Sharma (1999, 2000, 2008, 2013). The percentage similarities between rotifer assemblages of the sampled beels were calculated vide Sørensen’s index (Sørensen, 1948) and hierarchical cluster analysis was performed using SPSS (version 20). Ecological relationships between abiotic factors and richness were calculated by Pearson’s correlation coefficients (r); their P values were determined and significance was ascertained after Bonferroni corrections. The reference collections were deposited in the holdings of Freshwater Biology Laboratory, Department of Zoology, North-Eastern Hill University, Shillong. Results The details of the sampled beels and their recorded abiotic parameters (Mean ± SD) are indicated in Table 1. Water temperature ranged between 23.4 ± 1.9-24.2 ± 2.3°C; pH between 6.51 ± 0.16-7.04 ± 0.19; specific conductivity between 110.2 ± 20.8- 210.4 ± 41.3 µS/cm; dissolved oxygen between 5.1 ± 1.8-7.8 ± 0.7 mg/l; free CO2 between 10.3 ± 2.4- 14.8 ± 4.6 mg/l; total alkalinity between 62.2 ± 13.4- 113.5 ± 24.6 mg/l; and total hardness varied between 60.8 ± 13.6-113.0 ± 23.8 mg/l. We observed a total of 124 species including two new records from India namely Testudinella amphora (Fig. 2a) and Trichocerca uncinata (Fig. 2b) and globally interesting Brachionus kostei (Fig.3a); Keratella edmondsoni (Fig. 3b), Lecane blachei (Fig. Figure 1. District map of Assam state indicating location of Majuli River Island (insert Map of India indicating Assam state of northeast India). Figure 2. (a) Testudinella amphora Hauer and (b) Trichocerca uncinata (Voigt). 3 Sharma et al./ Rotifera of the floodplain lakes of Majuli River Island 3c), L. niwati (Fig. 3d) and Filinia camasecla (Fig. 3e). In addition, Brachionus durgae, Keratella tecta, Colurella adriatica, Conochilus unicornis, Lecane bifurca, Lepadella lindaui, L. minuta, L. triba, Mytilina michelangellii, Pleosoma lenticulare and Trichocerca scipio are new records to Majuli Rotifera thus updating their total tally to 144 species (Appendix I). Total richness in individual beels (Appendix II) ranged between 60-100 species and recorded 59.7-90.4% community similarities vide Figure 3. (a) Brachionus kostei Shiel (after Sharma, 2014), (b) Keratella edmondsoni Ahlstrom, (c) Lecane blachei Berzins, (d) Lecane niwati Segers, Kothetip and Sanoamuang and (e) Filinia camascela Myers. Figure 4. Hierarchical cluster analysis of Rotifer assemblages of different beels. 4 Int. J. Aquat. Biol. (2015) 3(1): 1-13 Sørensen’s index (Table 2). The hierarchical cluster analysis between Rotifer assemblages of different beels is shown in Figure 4. Discussion Water temperature concurred with geographical location of the sampled beels. The slightly acidic to circum-neutral and well-oxygenated waters of different beels are notable for low ionic concentrations as reflected by specific conductivity values; the latter warrant inclusion of these ecosystems under ‘Class I’ category of trophic classification vide Talling and Talling (1965). Free CO2 occurred in all beels during the study period which, in turn, are characterized by ‘bicarbonate alkalinity’ and ‘moderately hard’ to ‘hard-water’ character. A total of 124 species, belonging to 32 genera and 17 families, observed from beels of Majuli River Island reflect rich Rotifera assemblage and are of biodiversity value as ~52.0% and ~30.0% species of the taxon known till date from northeast India (NEI) Parameters↓ Beels→ Bhereki* Ghotonga* Holmari* Chela* Chakuli* Khorkhoria* Latitude 26°57′09.1″N 27°01′52.7″N 26°59′17.3″N 27° 04′58.2″N 26°56′40.3″N 26° 56′47.4″N Longitude 94°12′23.0″E 94°15′28.7″E 94°12′30.6″E 94° 17′51.9″E 94°09′01.9″E 94°12′28.8″E Altitude 67 m ASL 73 m ASL 75 m ASL 89 m ASL 69 m ASL 74 m ASL Water Temperature o C 23.7 ± 1.7 23.9 ± 1.7 23.6 ± 1.7 23.4 ± 1.9 23.6 ± 1.9 23.9 ± 1.8 pH 6.67 ± 0.23 6.51 ± 0.16 6.87 ± 0.13 7.04 ± 0.19 6.82 ± 0.18 6.80 ± 0.24 Sp. Conductivity µS/cm 140.7 ± 24.4 121.4 ± 26.8 173.6 ± 32.5 210.4 ± 41.3 180.8 ± 37.8 172.1 ± 44.4 Dissolved oxygen mg/l 6.3 ± 0.9 6.2 ± 1.0 7.1 ± 0.8 7.8 ± 0.7 6.2 ± 0.8 6.4 ± 1.2 Free CO2 mg/l 13.6 ± 4.0 13.8 ± 3.4 10.2 ± 2.8 10.3 ± 2.4 14.8 ± 4.6 13.9 ± 5.0 Total Alkalinity mg/l 70.3 ± 20.7 62.2 ± 13.4 92.3 ± 14.2 113.5 ± 24.6 105.8 ± 29.0 90.2 ± 29.9 Total Hardness mg/l 69.8 ± 20.3 60.8 ± 13.6 89.3 ± 16.9 113.0 ± 23.8 104.0 ± 26.2 88.8 ± 27.2 Parameters↓ Beels→ Doriya Dubori Tuni Baatomaari Jur Chereki Latitude 26°57′27.7″N 26°57′01.9″N 26° 58′35.3″N 26°59′25.9″N 26°59′45.3″N 26°58′25.4″N Longitude 94°10′02.4″E 94°16′13.8″E 94°15′57.8″E 94°13′08.0″E 94°14′34.4″E 94°10′38.7″E Altitude 70 m ASL 70 m ASL 67 m ASL 71 m ASL 71 m ASL 67 m ASL Water Temperature o C 24.2 ± 2.3 24.1 ± 1.9 23.9 ± 2.1 24.0 ± 1.9 23.9 ± 2.5 24.2 ± 1.7 pH 6.70 ± 0.32 6.61 ± 0.19 6.69 ± 0.14 6.87 ± 0.13 6.71 ± 0.14 6.62 ± 0.21 Sp. Conductivity µS/cm 110.2 ± 20.8 132.4 ± 18.6 123.6 ± 23.0 114.2 ± 20.5 130.8 ± 24.6 128.2 ± 33.2 Dissolved oxygen mg/l 5.8 ± 1.2 7.0 ± 0.9 5.1 ± 1.8 6.2 ± 0.9 5.9 ± 1.1 6.1. ± 1.0 Free CO2 mg/l 12.0 ± 5.2 11.8 ± 4.2 12.2 ± 1.9 11.4 ± 1.9 12.7 ±3.5 12.1 ± 3.6 Total Alkalinity mg/l 67.3 ± 12.2 72.2 ± 11.4 82.3 ± 12.3 91.5 ± 16.2 88.9 ± 12.9 90.8 ± 16.6 Total Hardness mg/l 62.8 ± 12.6 70.8 ± 10.6 79.1 ± 15.6 89.0 ± 12.8 81.4 ± 12.0 86.9 ± 17.0 * Sampled monthly between September, 2010–August, 2012; others sampled during winter (December/January), pre-monsoon (March-May), monsoon (June-August) and post-monsoon (September-October) between September, 2010–August, 2012. Table 1. The sampled beels of Majuli and their abiotic parameters (Mean ± SD). Beels 1 2 3 4 5 6 7 8 9 10 11 12 1 - 89.9 83.8 90.4 87.7 86.7 73.4 66.2 66.2 71.7 71.1 71.8 2 - 84.1 84.7 80.6 88.2 74.2 70.0 72.7 75.3 69.6 76.0 3 - 87.0 81.0 83.5 67.9 65.3 63.8 66.7 74.5 73.5 4 - 80.0 84.1 72.0 65.8 62.9 65.7 75.0 71.5 5 - 85.7 67.9 61.0 62.2 66.7 69.1 63.8 6 - 73.3 64.9 64.9 73.0 68.4 70.5 7 - 73.3 66.7 73.6 80.9 82.4 8 - 79.5 65.4 70.0 77.3 9 - 72.0 59.7 75.4 10 - 67.5 75.4 11 - 76.0 12 - 1-Bhereki, 2-Ghotonga, 3-Holmari, 4-Chakuli, 5-Chela, 6-Khorkhoria, 7-Doriya, 8-Dubori, 9-Tuni, 10- Baatomari, 11-Jur, 12-Chereki. Table 2. Percentage similarities between Rotifera assemblages of Majuli beels. 5 Sharma et al./ Rotifera of the floodplain lakes of Majuli River Island and India, respectively. Besides, our collections from this limited geographical study area include rich higher diversity of the taxon comprising ~68.0 and ~45.0% of genera and ~74.0 and ~65.0% of the families known from NEI and India, respectively. Testudinella amphora and Trichocerca uncinata are new additions to Indian Rotifera. The former is known from Australian, Neotropical and Oriental regions (Segers, 2007); it is examined from the last region from Thailand (Sa-Ardrit et al., 2013) and Vietnam (Trinh Dang et al., 2013), and the present report extends its distribution to the Indian sub- region. The Holarctic Trichocerca uncinata is a noteworthy new report from the Oriental region; the eastern Himalayan tropical-latitude populations of this cold-water species may represent glacial relicts as hypothesized by Segers (1996). This study adds eleven species to the rotifer fauna of Majuli studied vide Sharma (2014), thereby, raising their total tally to 144 species and thus affirm our hypothesis (Sharma, 2005, 2009a; Sharma and Sharma, 2008, 2014a) on habitat diversity and environmental heterogeneity of the Brahmaputra river basin floodplains. The sampled beels are species-rich than 110 rotifer species (Arora and Mehra, 2003) known from the backwaters of Yamuna River at Delhi while these are distinctly diverse than the reports of 48 species from 37 beels (Sarma, 2000) and 64 species from 12 beels of the Pobitora Wildlife Sanctuary (Sharma, 2006) of Assam state of NEI; 27 species from two floodplain lakes of Kashmir (Khan 1987); and 38 species from four ox-bow lakes and nine floodplain lakes of South-eastern West Bengal (Khan, 2003). We caution on over-emphasis on comparisons with some ad-hoc Indian reports with incomplete species inventories and inadequate sampling. The occurrence of biogeographically interesting elements namely the Australasian Brachionus kostei; the Oriental endemics Keratella edmondsoni, Lecane blachei, L. niwati and Filinia camasecla; the Palaeotropical Lepadella discoidea, L. vandenbrandei, Lecane lateralis and L. unguitata; and cosmo (sub) tropical Brachionus durgae imparts biodiversity value to our report. Of these, Brachionus kostei, Lecane niwati and Lepadella vandenbrandei are observed till date from this country from NEI with L. niwati known only from Majuli and Loktak basin (Sharma and Sharma, 2014b). Amongst the species of regional distribution interest, Lepadella benjamini, L. dactyliseta, L. elongata, L. quinquecostata, Lecane doryssa, L. pusilla, Macrochaetus longipes, Mytilina michelangellii and Testudinella tridentata are known to be restricted to NEI. Total richness in individual Majuli beels (60-100, 77 ± 12 species) needs cautious analysis with two beels indicating 100 species each while below average richness noticed in seven beels; the latter is hypothesized to invasion of Eichhornia crassipes in these wetlands. The results, however, broadly concur with 69-93 species listed from various beels of Assam (Sharma and Sharma, 2008) and also with 71 and 75 species reported from Utra and Waithou pats, respectively of Manipur (Sharma, 2011) but differ from relatively lower richness (62-73 species) observed from 15 floodplain lakes (pats) of Manipur (Sharma, 2009b). On the other hand, Majuli beels record lower rotifer diversity than the reports of 151 (Koste 1974) and 148 species from Rao Tapajos and Lago Camaleao (Koste and Robertson, 1983), respectively; 130 species from Lake Guarana, Brazil (Bonecker et al., 1994); 136 species (Iyi-Efi Lake) and 124 species (Oguta lake) from Niger delta (Segers et al., 1993). Further, Majuli rotifers are less diverse than that of 106 taxa from Thale-Noi Lake, Thailand (Segers and Pholpunthin, 1997); 104 species from Laguana Bufeos, Bolivia (Segers et al., 1998); and 114 taxa from the Rio Pilcomayo National park, Formosa, Argentina (Jose De Paggi, 2001). High rotifer community similarities amongst the sampled beels (59.7-90.4% vide Sørensen’s index) and ~ 61.0% instances in the matrix with similarity values between 71-90% reflect more homogeneity in their composition. This is attributed to common occurrence of several Lecane and Lepadella species in various beels in particular. Peak similarity 6 Int. J. Aquat. Biol. (2015) 3(1): 1-13 between Bhereki and Chakuli beels is corroborated by their cluster groupings while lowest similarity value is observed between Tuni and Jur beels. Rotifera assemblages of Holmari and Khorkhoria beels with high similarity (88.4%) also exhibit closer affinity vide hierarchical cluster analysis. On the other hand, Dubori beel indicates greatest divergence in its species composition and is followed by Baatomari beel. The rotifer taxocoenosis (overall and in individual beels) is predominantly tropical with rich diversity of ‘tropic centered’ Lecane (42 species; 21-37, 28 ± 5 species) and common occurrence of several cosmotropical and pantropical species while Lecanidae > Lepadellidae collectively contribute the bulk of species (66 species, ~53.0%) as well as in individual beels (31-57, 42 ± 8 species). The relative consistency of the importance of periphytic taxa of the two most diverse families (~51.0-59.0%) supports hypothesis of Green (2003) on the possibility of assemblage rules for the periphytic rotifer community. On the contrary, paucity of Brachionus spp. is noteworthy; it may partly be attributed to the lack of definite pelagic habitats (De Manuel, 1994) in the floodplains, shallow nature and the growth of aquatic macrophytes. The specific observations are, however, desired to highlight factors limiting their occurrence in Majuli beels particularly in light of the report of 18 Brachionus species in Assam state (Sharma and Sharma, 2014c) with 16 species occurring in the Brahmaputra floodplains (Sharma and Sharma, 2014d). Of the six monthly sampled beels, the monthly rotifer richness varied between 24 ± 7 species (Chela beel) - 34 ± 7 species (Khorkhoria beel); it lacked any pattern of monthly or annual variations. Amongst seasonally sampled six beels, the richness varied between 33 ± 5 species (Doriya beel) - 42 ± 7 species (Chereki beel) with maximum up to 53 and 54 species/sample in Doryia and Chereki beels, respectively but indicated no pattern of seasonal variations. The individual abiotic factors indicate much limited significant on the richness with significant positive and inverse correlations with rainfall only in Holmari (r = 0.551, p = 0.0026) and Chela (r = -0.588, p = 0.0013) beels, respectively. This generalization concurred with the results of Sharma (2005, 2009b) and Sharma and Sharma (2012b) but is in contrast to notable influence of abiotic factors reported by Sharma and Sharma (2005b) and Sharma (2009a). In conclusion, this study indicates rich and diverse Rotifera assemblage of Majuli beels in the Indian context with various interesting species and is a useful contribution to the rotifer diversity in the floodplain ecosystems of India. Our collections are yet biased towards planktonic and semi-planktonic taxa while specific analyses of periphytic, benthic and sessile taxa are likely to up-date the species inventory. The rotifers-aquatic macrophytes associations in these fluvial wetlands, the flushing influence of the Brahmaputra waters on the rotifer assemblages and their subsequent re-colonization merits attention due to lack of such works from India. Acknowledgements The senior author (BKS) acknowledges the support of the Ministry of Environment & Forests (Govt. of India) sponsored project No. 22018-09/2010-CS (Tax) for collections of the samples for this study. The senior author also thanks the Head, Department of Zoology, North- Eastern Hill University, Shillong for laboratory facilities. The authors have no conflict of interests. References A.P.H.A. (1992). Standard Methods for the Examination of Water and Wastewater (18th Ed.). American Public Health Association, Washington D. C. pp. 1198. Arora J., Mehra N.K. (2003). Species diversity of planktonic and epiphytic rotifers in the backwaters of the Delhi segment of the Yamuna River, with remarks on new records from India. Zoological Studies, 42(2): 239-247. Bonecker C.C., Lansac-Tôha F.A., Staub A. (1994). Qualitative study of Rotifers in different environments of the high Parana River floodplain (Ms), Brazil. 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Sharma B.K., Sharma S. (2014d). Floodplains of the Brahmaputra river basin-globally interesting ecotones with rich Rotifer (Rotifera: Eurotatoria) biodiversity. In: R.K. Sinha, B. Ahmed (Eds.). Rivers for Life - Proceedings of the International Symposium on River Biodiversity: Ganges–Brahmaputra - Meghna River System, Ecosystems for Life, A Bangladesh - India Initiative, IUCN, International Union for Conservation of Nature, 258-270. Sharma S. (2006). Rotifer diversity (Rotifera: Eurotatoria) of floodplain lakes of Pobitora Wild-Life Sanctuary, Assam. Records of the Zoological Survey of India, 106(3): 76-89. Sharma S., Sharma B.K. (2008). Zooplankton diversity in floodplain lakes of Assam. Records of the Zoological Survey of India, Occasional Paper No. 290: 1-307. Sharma S., Sharma B.K. (2013). Faunal Diversity of Aquatic Invertebrates of Deepor Beel (a Ramsar site), Assam, northeast India. Wetland Ecosystem Series, 17: 1-226. Talling J.F., Talling I.B. (1965). The chemical composition of African lake waters. Internationale Revue der gesamten Hydrobiologie, 50: 421-463. Trinh Dang M., Segers H., Sanoamuang L. (2013). Rotifers from Thuy Tien lake and Nhu Y river in central Vietnam, with a description of Ploesoma asiaticum new species (Rotifera: Monogononta). Journal of Limnology, 72 (2): 276-286. 9 Sharma et al./ Rotifera of the floodplain lakes of Majuli River Island Family: Brachionidae 1. Anuraeopsis fissa Gosse, 1851 2. Brachionus angularis Gosse, 1851 3. B. durgae Dhanapathi, 1974** 4. B. calyciflorus Pallas, 1766 5. B. dichotomus reductus Koste & Shiel, 1980 6. B. diversicornis (Daday, 1883) 7. B. falcatus Zacharias, 1898 8. B. kostei Shiel, 1983 9. B. quadridentatus Hermann, 1783 10. Keratella cochlearis (Gosse, 1851) 11. K. edmondsoni Ahlstrom, 1943 12. K. lenzi Hauer, 1953 13. K. tecta (Gosse, 1851)** 14. K. tropica (Apstein, 1907) 15. Platyias quadricornis (Ehrenberg, 1832) 16. Plationus patulus (O.F. Müller, 1786) Family: Euchlanidae 17. Beauchampiella eudactylota (Gosse, 1886) 18. Euchlanis dilatata Ehrenberg, 1832 19. E. incisa Carlin, 1939 20. E. triquetra Ehrenberg, 1838 21. Dipleuchlanis ornata Segers, 1993 22. D. propatula (Gosse, 1886) 23. Tripleuchlanis plicata (Levander, 1894) Family: Mytilinidae 24. Lophocharis oxysternon (Gosse, 1851) 25. Mytilina acanthophora Hauer, 1938 26. M. bisulcata (Lucks, 1912) 27. M. michelangellii Reid & Turner** 28. M. ventralis (Ehrenberg, 1830) Family: Trichotriidae 29. Macrochaetus collinsi (Gosse, 1867) 30. M. longipes Myers, 1934 31. M. sericus (Thorpe, 1893) 32. Trichotria tetractis (Ehrenberg, 1830) Family: Lepadellidae 33. Colurella adriatica Ehrenberg, 1831** 34. Colurella colurus (Ehrenberg, 1830) 35. C. obtusa (Gosse, 1886) 36. C. uncinata (O.F. Müller, 1773) 37. Lepadella acuminata (Ehrenberg, 1834) 38. L. apsida Harring, 1916 39. L. benjamini Harring, 1916 40. L. biloba Hauer, 1958 41. L. costatoides Segers, 1992 42. L. dactyliseta (Stenroos, 1898) 43. L. discoidea Segers, 1993 44. L. elongata Koste, 1992 45. L. eurysterna Myers, 1942 46. L. latusinus (Hilgendorf, 1899) 47. L. lindaui Koste, 1981** 48. L. minuta (Weber & Montet, 1918)** 49. L. ovalis (O.F. Müller, 1786) 50. L. patella (O.F. Müller, 1773) 51. L. quinquecostata (Lucks, 1912) 52. L. rhomboides (Gosse, 1886) 53. L. triptera Ehrenberg, 1832 54. L. triba Myers, 1934** 55. L. vandenbrandei Gillard, 1952 56. L. (Heterolepadella) apsicora Myers, 1934 57. L. (H.) ehrenbergi (Perty, 1850) 58. L. (H.) heterostyled (Murray, 1913) 59. Squatinella lamellaris (O. F. Müller, 1786) Family: Lecanidae 60. Lecane aculeata (Jakubski, 1912) 61. L. arcula Harring, 1914 62. L. bifurca (Bryce, 1892)** 63. L. blachei Berzins, 1973 64. L. bulla (Gosse, 1851) 65. L. closterocerca (Schmarda, 1859) 66. L. crepida Harring, 1914 67. L. curvicornis (Murray, 1913) 68. L. decipiens (Murray, 1913) 69. L. doryssa Harring, 1914 70. L. elongata Harring & Myers, 1926 71. L. flexilis (Gosse, 1886) 72. L. furcata (Murray, 1913) 73. L. haliclysta Harring & Myers, 1926 74. L. hamata (Stokes, 1896) 75. L. hornemanni (Ehrenberg, 1834) 76. L. inermis (Bryce, 1892) 77. L. inopinata Harring & Myers, 1926 78. L. lateralis Sharma, 1978 79. L. leontina (Turner, 1892) 80. L. ludwigii (Eckstein, 1883) 81. L. luna (O.F. Müller, 1776) 82. L. lunaris (Ehrenberg, 1832) 83. L. monostyla (Daday, 1897) Appendix I: Systematic list of Rotifer taxa known from Majuli River Island Phylum: Rotifera Class: Eurotatoria Subclass: Monogononta Order: Ploima 10 Int. J. Aquat. Biol. (2015) 3(1): 1-13 84. L. nitida (Murray, 1913) 85. L. niwati Segers, Kotethip & Sanoamuang, 2004 86. L. obtusa (Murray, 1913) 87. L. ohioensis (Herrick, 1885) 88. L. papuana (Murray, 1913) 89. L. paxiana Hauer, 1940 90. L. ploenensis (Voigt, 1902) 91. L. pusilla Harring, 1914 92. L. pyriformis (Daday, 1905) 93. L. quadridentata (Ehrenberg, 1830) 94. L. rhytida Harring & Myers, 1926 95. L. signifera (Jennings, 1896) 96. L. simonneae Segers, 1993 97. L. stenroosi (Meissner, 1908) 98. L. styrax (Harring & Myers, 1926) 99. L. tenuiseta Harring, 1914 100. L. thienemanni (Hauer, 1938) 101. L. undulata Hauer, 1938 102. L. unguitata (Fadeev, 1925) 103. L. ungulata (Gosse, 1887) Family : Notommatidae 104. Cephalodella forficula (Ehrenberg, 1830) 105. C. gibba (Ehrenberg, 1830) 106. Monommata longiseta (O. F. Müller, 1786) 107. M. maculata Harring & Myers, 1930 108. Notommata pachyura (Gosse, 1886) Family: Scaridiidae 109. Scaridium longicaudum (O.F. Müller, 1786) Family : Trichocercidae- 13/1 110. Trichocerca abilioi Segers & Sarma, 1993 111. T. bicristata (Gosse, 1887) 112. T. cylindrica (Imhof, 1891) 113. T. elongata (Gosse, 1886) 114. T insignis (Herrick, 1885) 115. T. insulana (Hauer, 1937) 116. T. pusilla (Jennings, 1903) 117. T. rattus (O.F. Müller, 1776) 118. T. scipio (Gosse, 1885)** 119. T. similis (Wierzejski, 1893) 120. T. tenuior (Gosse, 1886) 121. T. tigris (O.F. Müller, 1786) 122. T. uncinata (Voigt, 1902)* 123. T. voluta (Murray, 1913) 124. T. weberi (Jennings, 1903) Family : Asplanchnidae 125. Asplanchna priodonta Gosse, 1850 Family : Synchaetidae 126. Pleosoma lenticulare Herrick, 1885** 127. Polyarthra vulgaris Carlin, 1943 Family : Dicranophoridae 128. Dicranophoroides caudatus (Ehrenberg, 1834) 129. D. forcipatus (O. F. Müller, 1786) Order: Flosculariaceae Family: Conochilidae 130. Conochilus unicornis Rousselet, 1892** Family : Floscularidae 131. Sinantherina socialis (Linne, 1758) 132. S. spinosa (Thorpe, 1893) Family : Hexarthridae 133. Hexarthra mira (Hudson, 1871) Family : Testudinellidae 134. Testudinella amphora Hauer, 1938* 135. Testudinella emarginula (Stenroos, 1898) 136. T. patina (Hermann, 1783) 137. T. tridentata Smirnov, 1931 138. Pompholyx sulcata Hudson,1885 Family : Trochosphaeridae 139. Filinia camasecla Myers, 1938 140. F. longiseta (Ehrenberg, 1834) 141. Trochosphaera aequatorialis Semper, 1872 Sub-class : Digononta Order : Bdelloidea Family : Philodinidae 142. Philodina roseola Ehrenberg, 1832 143. Rotaria neptunia (Ehrenberg, 1830) 144. R. rotatoria (Pallas, 1766) ------------------------------------------------------------------------------------------------------------------------------------------------ * New record from India, ** New record from Majuli River Island 11 Sharma et al./ Rotifera of the floodplain lakes of Majuli River Island Taxa↓ Beels Sr. No.→ 1 2 3 4 5 6 7 8 9 10 11 12 Order: Ploima Family: Asplanchnidae 1. Asplanchna priodonta Gosse + + + + - + + + - + + + Family: Brachionidae 2. Anuraeopsis fissa Gosse + + - - + + + + + + + - 3. Brachionus angularis Gosse - - - - - - + - - + + + 4. B. durgae Dhanapathi - - - - - - + + - - - + 5. B. falcatus Zacharias - - - - - - + - + + - + 6. B. kostei Shiel - - - - - - + - + - - - 7. Brachionus quadridentatus Hermann + + + + + + + + + + + + 8. Keratella cochlearis (Gosse) + + + + + + + + + + + + 9. K. edmondsoni Ahlstrom - - - - - - - - - - - + 10. K. lenzi Hauer + + - + + + - - - + - + 11. K. tecta (Gosse) - + - - - - + + + - - + 12. K. tropica (Apstein) + - + + + + + - + + + + 13. Platyias quadricornis (Ehrenberg) + + + + + + + + + + + + 14. Plationus patulus (O.F. Müller) + + + + + + + + + + + + Family: Euchlanidae 15. Beauchampiella eudactylota (Gosse) + + + + - + + - - + + + 16. Dipleuchlanis propatula (Gosse) + - + + + + + + + + + + 17. Euchlanis dilatata Ehrenberg + + + + + + + + + + + + 18. E. triquetra Ehrenberg + + - - + - - - + + + + 19. Tripleuchlanis plicata (Levander) - + + + - + - + + - - + Family: Flosculariidae 20. Sinantherina socialis (Linne) - + - - - + + + + + - + 21. S. spinosa (Thorpe) + + + + + + + + + + + + Family: Lecanidae 22. Lecane aculeata (Jakubski) + + + + + + + - - + + + 23. L. arcula Harring - - - - - - + + - + + - 24. L. bifurca (Bryce) - - - - - - - + + + - + 25. L. blachei Berzins - + + + - + + + + - + + 26. L. bulla (Gosse) + + + + + + + + + + + + 27. L. closterocerca (Schmarda) + + + + + + + + + + + + 28. L. crepida Harring - + + - - - + - - + + + 29. L. curvicornis (Murray) + + - + + + + + + + + + 30. L. decipiens (Murray) - - - - - - + - - - + + 31. L. doryssa Harring + + - - + + + - + + - + 32. L. flexilis (Gosse) - - - - - - - + + + - + 33. L. furcata (Murray) + + + + + + + + - + + + 34. L. haliclysta Harring & Myers - - - - - - + - - - + + 35. L. hamata (Stokes) + + + + + + + + + + + + 36. L. hornemanni (Ehrenberg) + + + + + + + - - - + + 37. L. inermis (Bryce) + + + + - + - - + - - + 38. L. inopinata Harring & Myers + + - - - + + - - - - - 39. L. lateralis Sharma + + + + + - + + + - + + 40. L. leontina (Turner) + + + + + + + + + + + + 41. L. ludwigii (Eckstein) + + + + + + + + + + - + 42. L. lunaris (Ehrenberg) + + + + + + + + + + + + 43. L. luna (O.F. Müller) + + + + + + + + + + + + Appendix II: Species composition of Rotifera of beels of Majuli River Island. 12 Int. J. Aquat. Biol. (2015) 3(1): 1-13 Appendix II: Species composition of Rotifera of beels of Majuli River Island (contd.). Taxa↓ Beels Sr. No.→ 1 2 3 4 5 6 7 8 9 10 11 12 44. L. monostyla (Daday) - + - - + + + - + + + - 45. L. nitida (Murray) - + + - - - - + + - - + 46. L. niwati Segers, Kotethip & Sanoamuang - - - - - - + - - - + + 47. L. obtusa (Murray) + + + + + + + - - + + + 48. L. ohioensis (Herrick) + + - + - - + + + + + + 49. L. papuana (Murray) + + + + + + + + + + + + 50. L. paxiana Hauer - - - - - - + - - + + - 51. L. ploenensis (Voigt) + + + + + + + + + - + + 52. L. pusilla Harring - + + - - - - + - + + + 53. L. pyriformis (Daday) + + + + + + + - - + + + 54. L. quadridentata (Ehrenberg) + + + + + + + + + + + + 55. L. rhytida Harring & Myers - - - - - - + + - - - - 56. L. signifera (Jennings) + + + + + + + + + + + + 57. L. stenroosi (Meissner) + + + + - + + - - + + + 58. L. styrax (Harring & Myers) - - - - - - + + + + + + 59. L. tenuiseta Harring - - - - - - + - + - - + 60. L. thienemanni (Hauer) - - - - - - + + - - + - 61. L. undulata Hauer - + - - - - + + + + - + 62. L. unguitata (Fadeev) + + + + + + + + + + + + 63. L. ungulata (Gosse) + + + + - + + + + + + + Family: Lepadellidae 64. Colurella adriatica Ehrenberg - - - - - - - + + - - + 65. Colurella obtusa (Gosse) + + + + + + + + + + + + 66. C. uncinata (O.F. Müller) + + + + + + + + + + + + 67. Lepadella acuminata(Ehrenberg) + + + + + + + - - - - + 68. L. apsida Harring + + - + - + - + - + - + 69. L. benjamini Harring + + + + + + + + - - + + 70. L. biloba Hauer - - - - - - + - + + + + 71. L. costatoides Segers - - - - - - + + + - + + 72. L. dactyliseta (Stenroos) - - - - - - + + - - + - 73. L. discoidea Segers + + + - + + + - + + - + 74. L. elongata Koste + + - + + + + - - - - - 75. L. lindaui Koste - - - - - - + - - - + + 76. L. minuta (Weber & Montet) - - - - - - - + + - - - 77. L. ovalis (O.F. Müller) + + + + + + + + + + + + 78. L. patella (O.F. Müller) + + + + + + + + + + + + 79. L. quinquecostata (Lucks) - - - - - - + + - - - + 80. L. rhomboides (Gosse) + + + + - - + + + - + + 81. L. triba Myers - - - - - - + + - - + + 82. L. triptera Ehrenberg - - - - - - - + + + - + 83. L. vandenbrandei Gillard - - - - - - + + - - + + 84. L. (Heterolepadella) apsicora Myers - - - - - - + + + - + - 85. L. (H.) ehrenbergi Perty + + + + + + + + + + + + 86. L. (H.) heterostyla (Murray) - + - + - + + + + + + + 87. Squatinella lamellaris (O.F. Müller) + + - + + + + + - - - - Family: Mytilinidae 88. Lophocharis oxysternon (Gosse) - - + + - + + - - - + + 89. Mytilina acanthophora Hauer + + - - - + - + + + - - 90. M. bisulcata (Lucks) + - + + + - + + - - + + 13 Sharma et al./ Rotifera of the floodplain lakes of Majuli River Island Taxa↓ Beels Sr. No.→ 1 2 3 4 5 6 7 8 9 10 11 12 91. M. michelangellii Reid & Turner - - - - - - + + + + - + 92. M. ventralis (Ehrenberg) + + + + + + + - - + + + Family: Notommatidae + 93. Cephalodella forficula - + + - + + - - + + - - 94. C. gibba(Ehrenberg) + + + + + + + + + - + - 95. Monommata longiseta(O.F. Müller) + + + + + + + - - - + + Family: Scaridiidae 96. Scaridium longicaudum ( Müller) + + + + + + + + + + - + Family: Synchaetidae 97. Pleosoma lenticulare Herrick - - - - - - + + - - + + 98. Polyarthra vulgaris Carlin + + + + + + + + + + + + Order: Flosculariaceae Family: Conochilidae 99. Conochilus unicornis Rousselet - - - - - - + + + + - + Family: Hexarthridae 100. Hexarthra mira (Hudson) - - - - - - + - - - + + Family: Testudinellidae 101. Testudinella amphora Hauer - - - - - - + - - - - - 102. Testudinella emarginula Stenroos + + + - + + + + + + - + 103. T. patina (Hermann) + + + + + + + + + + + + 104. T. tridentata Smirnov - - - - - + + - - + - + 105. Pompholyx sulcata Hudson + + + + - - - + + - - + Family: Trichocercidae 106. Trichocerca bicristata (Gosse) - - - - - - + + + + - + 107. T. cylindrica (Imhof) + + + + + + + - - + + + 108. T. elongata (Gosse) - - - - - - - + + - + + 109. T. insignis (Herrick) + + + - + + + + - + - + 110. T. rattus (O.F. Müller) + + + + - - + + + + + + 111. T. scipio (Gosse) - - - - - - - + + - - + 112. T. similis (Wierzejski) + + + + + + + - - + + - 113. T. tigris (O.F. Muller) + + - - + + + + + - - + 114. T. uncinata (Voigt) - - - - - - - + - - - - 115. T. weberi (Jennings) - - - - - - - + - + + + Family: Trichotriidae 116. Macrochaetus longipes Myers - + + - - + - - + + - + 117. M. sericus (Thorpe) + + + + + + + + + - + + 118. Trichotria tetractis (Ehrenberg) + + + + + + + + + + + + Family: Trochosphaeridae 119. Filinia camasecla Myers - - - - - - + - - + - - 120. Filinia longiseta (Ehrenberg) + + + + + + - + + - + + 121. Trochosphaera aequatorialis Semper - - - - - + + + - - - - Sub-class: Bdelloidea Family: Philodinidae 122. Philodina citrina Ehrenberg + + + + + + - + - - + - 123. Rotaria neptunia (Ehrenberg) + + - + - - + - + + - - 124. R. rotatoria (Pallas) - - + - + + - + - - + - Total richness (species) 70 79 66 65 60 73 100 82 75 75 79 100 1-Bhereki, 2-Ghotonga, 3-Holmari, 4-Chakuli, 5-Chela, 6-Khorkhoria, 7-Doriya, 8-Dubori, 9-Tuni, 10-Baatomari, 11- Jur, 12-Chereki. Appendix II: Species composition of Rotifera of beels of Majuli River Island (contd.).