Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN 2249-9598, Volume-08, Issue-05, Sept-Oct 2018 Issue

Osteology of brachysoma (Günther) young Population from Northern of R. N. Raut a, S. S. Kharat b aDepartment of Zoology, Elphinstone College, Mumbai- 400032. India bDepartment of Zoology, Modern College of Arts, Commerce And Science, Ganeshkhind, Pune- 411007. India Abstract Family is peculiar among as it has been difficult to resolve the position of this family phylogenetically. This has been partly because of lack of detailed morphological data for members of this family. Here we describe osteology of (Günther) based on cleared and counterstained specimens for bone and cartilage. We describe in fraorbital, hyoid and branchial skeleton characters. These observations have been compared with earlier observations. There are notable differences in anterior ceratohyal and parhypural, and second basibranchial bones. This study will be important in future studies. KEYWORDS: infraorbital, hyoid arch, branchial arch, skeleton.

Introduction Horabagrus Jayaram, 1955 is an endemic found only in west flowing rivers of Western Ghats of India. The genus currently comprises of two valid Horabagrus brachysoma (Günther, 1864) and H. nigricollaris(Pethiyagoda&Kottelat, 1994), both of which are threatened (Dahanukar et al. 2011). Horabagrus brachysoma commonly called as sun catfish, yellow catfish or Günther’s catfish was earlier considered to be endemic to the rivers and estuaries of and but now its range has extended till northern parts of Western Ghats (Katwate et al. 2012). This species is characterized by following set of characters like moderately elongated and compressed body, anterior depressed large head, sub terminal transverse mouth, large inferior eyes which are visible from ventral surface of head, dorsal and pectoral fin having serrated spine with 5–7 and 8-9 branched rays respectively; short adipose which is well separated from caudal fin base; ventral fin with i6 rays; long anal fin with iii23–iii28 rays, distinct brownish back dorsal side, sides pale yellow, white belly, a thick black shoulder spot and semilunar thick black ring at caudal base (Jayaram, 2006& 2010). Multiple stress factors like , habitat alteration, pollution, and minimum population doubling time have resulted in population decline of H. brachysoma in its native occurrence ranges and as a result of which this species has been listed as Vulnerable in IUCN Redlist (Raghavan and Ali, 2012). Osteocranium and Weberian apparatus of H.brachysoma has been studied previously. Tilak (1965) has studied descriptive osteology of the of family . Marceniuk and Menezes (2012) have used this family for outgroup comparison in study of Ariidae monophyly and intrafamilial relationships.In the current paper we describe and

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Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN 2249-9598, Volume-08, Issue-05, Sept-Oct 2018 Issue illustrate the skeletal anatomy of this species from Malvan region, Maharashtra. These descriptions are primarily based on cleared and stained specimens. Given the paucity of osteological information for H. barchysoma in the literature, we expanded the study to include appendicular and caudal osteology. Materials and methods: Field surveys were conducted in Gad River basin of Sindhudurga District located in south Konkan region of Maharashtra. Gad River, one of the west flowing rivers in northern Western Ghats, lies between 16° to 16° 20 ′ N latitude and 73° 30 ′ to 74° longitude. Specimen were collected in perennial second-order streams of Gad River near Bagayat village (16° 09 ′ 04.35 ′′ N and 73° 33 ′ 04.7 ′′ E). Proper identification of the species using available taxonomic literature(Jayaram, 2006& 2010)was carried out. Representative 05 specimens were collected for osteological study. The specimens were preserved in 4% formaldehyde for further study.Cleared and stained specimens were prepared following methods ofDingerkus and Uhler (1977). Dissections and osteological observations were made through Olympus SZX7 dissecting microscope. Line drawings were rendered using GIMPv. 2.8.10 and Inkscape v. 0.48.4 software.

Terminology Osteological nomenclature has been followed as perArratia,2003 and Lundberg and Baskin, 1969. For description of bilaterally paired cranial and appendicular skeletons, descriptions from left side of the body are made. Results and discussion: Osteological observations: Osteological observations were made on cleared and stained specimens (Fig 1). Vertebrae: Vertebral counts were taken for abdominal and post abdominal (or caudal) as well as total vertebrae. Counts were obtained from cleared and stained specimen. These counts were taken as per Roberts, 2003. The count began from the first vertebra bearing ribs. Abdominal and post abdominal vertebrae could be distinguished by their hemal spines. Abdominal vertebrae are all those with hemal spines lying anterior to the anal fin pterygophore. Vertebrae in the caudal fin peduncle or peduncularvertebrae are those lying posterior to a vertical line through the posterior most anal fin pterygophore. Total vertebrae are 34 of which caudal vertebrae are 10 and abdominal vertebrae are 24.

Opercular series, suspensorium and lower jaw bones Opercular bones are thin and well ossified. The opercle is subtriangular in shape. Its anteroventral margin is slightly convex. The preopercle is stout and narrow bone. The bone is ventrally little broad while dorsally it ends in a tip. Interopercle is anterior to the opercle to which it is attached. Its posterior margin is slightly convex. It is subtriangular in shape. The ventral part of opercle fits in a notch on less than half portion of posterior part of interopercle. Their anterior part is columnar and truncate (Fig. 2).

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Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN 2249-9598, Volume-08, Issue-05, Sept-Oct 2018 Issue

Hyomandibula is slender and contacts metapterygoid anteriorly and quadrate anteroventrally. Metapterygoid is anterodorsal to quadrate. It contacts hyomandibula through much of its posterior margin and posterodorsally tightly sutures with hyomandibula. Quadrate is a broad bone and bears prominent posteroventral process. It is closely associated with symplectic. Anteroventrally it bears a broad condyle which joins with lower jaw. Lower jaw consists of dentary, angular, articular and retroarticular bones. Of these angular, articular and retroarticular bones are fused into one bone on posterior margin of the jaw. The dentary is elongated and curved. In lateral view it can be seen as narrow posteriorly. The dorsal surface bears acicular teeth along the entire length. The dentary is grooved medially to receive Meckel cartilage (Fig. 2).

Infraorbital bones: Four infraorbitals are present. The infraorbital series is represented by lachrymal- antorbital. Infraobtial 1 and infraorbital 4 are slightly curved while infraorbital 3 is almost straight. The bones are ossified tubules (Fig. 3).

Hyoid and branchial arch: Hyoid arch comprises of dorsal and ventral hypohyals, anterior and posterior ceratohyals (Fig. 4). A series of branchiostegal rays are attached to anterior and posterior ceratohyals. The number of branchiostegal rays is 9 in H. brachysoma, of which 7 are attached to anterior ceratohyal while 1 is attached to the articular cartilage between both ceratohyals and 1 is attached to posterior ceratohyal. Anterior portion of anterior ceratohyals is columnar while its posterior portion is moderately thick but not compressed. Posterior ceratohyal is little longer than half to the length of anterior ceratohyals. Ventral hypohyal is slightly larger than dorsal hypohyal. It is anterolateral to the dorsal hypohyal. Both dorsal hypohyal articulate with anterior portion of parhypural, while ventral hypohyal articulates with posterior portion of parhypural. Parhypural is located on the hyoid arch medioventral region. It is a long bone with broad alary bone and is with a median oval foramen. The anterior margin of parurohyal is deeply notched. It bears laminar lateral expansions making its appearance triangular in ventral view. Its posterolateral processes are clearly visible. Its posterior portion is narrow and acute. Parurohyal of catfishes differs in mode of formation from other teleosts (Arratia and Schutze, 1990) and it is unique for this group. Parurohyal and urohyal are non synonymous in this context, so name parurohyal instead of traditional urohyal is used in terminologies. Posterolateral processes are long and conspicuous. Branchial arches consists of ceratobranchials 1-5, epibranchials 1-4 , infrapharyngobranchials 1-4, hypobranchials 1 and 2 and basibranchials 2 and 3. Ceratobranchials 1-5 are elongate. Ceratobranchial 1 is longest while ceratobranchial 5 is shortest and slightly broader. Its lateral surface is covered by teeth. Margin of ceratobranchial 1-4 bear a few irregularly distributed gill rakers. Ceratobranchial 1 and 2 articulate with short hypobranchial 1 and 2 respectively. Epibranchials are 1 and 2 are longer than epibranchials 3 and 4. These bear few gill rakers. Each epibranchial is separated from its ceratobranchial by large cartilage.

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Two basibranchials can be visualized. Basibranchial 1 is absent. Basibranchial3is short in comparison to basibranchial 2. Basibranchial2 is elongate and longest. Bothbasibranchialsare hourglass shaped bones. Bothbasibranchial 2-3 are ossified with cartilaginous caps. Infrapharyngobranchials 1-3 are ossified without tooth plates. Infrapharyngobranchials 1 and 2 are elongated and placed parallel to epibranchial 1 and 2 respectively. Infrapharyngobranchial 3 lies over the dorsal end of epibranchial 3. Infrapharyngobranchial 4 is a small elongated bone and is attached ventrally to an oval tooth plate bearing long conic teeth. (Fig. 4& fig. 5). Twohypobranchials are present of which hypobranchial1 is shell like in shape and stout in appearance. Hypobranchial 2 is short and shell like in shape. Hypobranchial 1 and 2 are well ossified with cartilaginous caps while hypobranchial 3 is represented by hypobranchial cartilage (Fig. 4).

Conclusion: Despite recent progress in catfish phylogeny, much remains to be done with respect to relationships among different groups of catfishes. Genus Horabagrus is no exception to this. Mo (1991) divided the traditional family Bagridae into three families i.e. Bagridae, Claroteidae and Austroglanididae. This analysis based on morphological data support close relationship among Bagridae (sensu stricto), Horabagrus and Pangasiidae. de Pinna (1993) has placed Horabagrus in its own family Horabagridae (Diogo and Peng, 2009). As per Sullivan et al. (2006) based on analysis of rag 1 and rag 2 nuclear genes Horabagridae forms part of big Asian clade but amongst them also its position has been unresolved. Even today the position of Horabagridae is not recognized. The present work might help in shedding some light on the position of Horabagridae in phylogenetic context.

Acknowledgements R. Raut is grateful to Principal, Elphinstone College, Mumbai for providing infrastructure facilities to carry out this work. Literature cited 1. Arratia G. and H. P. Schultze. 1990. The urohyal: development and homology within osteichthyans. Journal of morphology, 203: 247-282. 2. Arratia, G. 2003. Catfish head skeleton. An overview In: Catfishes. G. Arratia, B. G. Kapor, M. Chardon and R. Diogo (eds.) Science publishers, Inc. Enfield, NH, 812 pp. 3. Dahanukar, N., R. Raghavan, A. Ali, R. Abraham, &C. P. Shaji. 2011. The status and distribution of freshwater fishes of the Western Ghats, in The Status and Distribution of Freshwater Biodiversity in the Western Ghats, India, S. Molur, K. G. Smith, B. A.Daniel, and W. R. T. Darwall, Eds., chapter 3, pp. 21–48, IUCN, Cambridge, UK and Gland, Switzerland, Zoo Outreach Organisation, Coimbatore, India, 2011.

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4. de Pinna, M.C.C.1993. Higher-level Phylogeny of Siluriformes (Teleostei, Ostariophysi), with a New Classification of the Order. Unpublished Ph.D. Dissertation, City University of New York, New York. 5. Dingerkus, G., & L. D. Uhler. 1977. Enzyme clearing of alcian blue stained whole small vertebrates for demonstration of cartilage. Journal of Stain Technology, 52:229–232. 6. Diogo, R. & Z. Peng. 2009. State of the art of siluriform higher-level phylogeny. In: Grande, T., F. Poyato-Ariza & R. Diogo (eds.), Gonorynchiformes and ostariophysan relationships – a comprehensive review, Science Publishers (Enfield, US), 592 pp. 7. Günther, A. 1864. Catalogue of Fishes in the British Museum, vol. 5, British Museum, London. Xxii+455 pp. 8. J. P. Sullivan, J. G. Lundberg & M. Hardman. 2006. A phylogenetic analysis of the major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene sequences. Molecular Phylogenetics and Evolution, 41 (3): 636– 662. 9. Jayaram, K. C. 1955. The Palaearctic element in the fauna of peninsular India. Bulletin of the National Institute of Sciences of India. New Delhi. No. 7: 260-263. 10. Jayaram, K. C. 2006. Catfishes of India, Narendra Publishing House,New Delhi, India, 383 pp. 11. Jayaram, K. C. 2010. The Freshwater Fishes of the Indian Region, Narendra Publishing House, Delhi, India, 616 pp. 12. Katwate, U., R. Raut, M. Khot, M. Paingankar, & N. Dahanukar. 2012. Molecular Identification and Ecology of a Newly Discovered Population of Sun Catfish Horabagrus brachysoma from Northern Western Ghats of India. ISRN Zoology, 2012, Article ID 419320, 9 pages, 2012. doi:10.5402/2012/419320. 13. Lundberg, J. G. & Baskin, J. N. 1969. The caudal skeleton of the catfish, order Siluriformes. American Museum Novitates, 2398: 1-49. 14. Marceniuk, A. P. & N. A. Menezes. 2012. Phylogenetic analysis of the family Ariidae (Ostariophysi: Siluriformes), with a hypothesis on the monophyly and relationships of the genera. Zoological Journal of the Linnean Society, 165:534- 669. 15. Mo, T. P. 1991.Anatomy, relationships and systematics of the Bagridae (Teleostei: Siluroidei) with a hypothesis of siluroid phylogeny. Theses Zoologicae 17. Koeltz, Koenigstein, 216pp. 16. Pethiyagoda, R & M. Kottelat. 1994. Three new species of fishes of the genera Osteochilichthys (Cyprinidae), Travancoria (Balitoridae), and Horabagrus (Bagridae) from the , Kerala, India. Journal of the South Asian Natural History 1(1): 97-116. 17. Raghavan, R. & A. Ali. 2012. Horabagrus brachysoma, In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2.2011, http://www.iucnredlist.org/, 2012. 18. Roberts, T. R. & C. Vidthayanon. 1991. Revision of the tropical Asian catfish family Pangasiidae with biological observations and descriptions of three new

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species. Proceedings of the Philadelphia Academy of Natural Science, 143: 97- 144. 19. Roberts, T. R. 2003. Systematics and osteology of Leptoglaninae, a new subfamily of the African catfish family Amphiliidae, with descriptions of three new genera and six new species. Proceedings of the California Academy of Sciences, 54 (5): 81-132. 20. The GIMP team. 2013. GIMP v. 2.8.10. GNU Image Manipulation Programme. http://www.gimp.org 21. The Inkscape team. 2013. Inkscape v. 0.48.4. www.inkscape.org. 22. Tilak, R. 1965. The osteocranium and Weberian apparatus of the fishes of the family Bagridae (Pisces Siluroidei). GegenbaursmorphologischesJahrbuch, 107: 415- 443.

Fig.1: Horabagrus brachysoma cleared and stained specimen.Standard length- 32.8 mm.

Fig.2: Opercular series, suspensorium and lower jaw in lateral view left side.

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Fig.3:H. brachysoma infraorbital series in lateral view, left side.

Fig.4:H. brachysoma hyoid and branchial arches in ventral view.

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Fig.5:H. brachysoma branchial arches inner view in dorsal view.

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