Comparative Cranial Osteology of Hydrophis schistosus Daudin, 1803 and Hydrophis platurus (Linnaeus, 1766) (Elapidae: Hydrophiinae)


  • Zoological Survey of India, M-Block, New Alipore, Kolkata 700053
  • Zoological Survey of India, M-Block, New Alipore, Kolkata 700053
  • Zoological Survey of India, M-Block, New Alipore, Kolkata 700053
  • Zoological Survey of India, M-Block, New Alipore, Kolkata 700053



Basisphenoid process, Cranial morphology, Hydrophiinae, Piscivorous, Hydrophis


The viviparous sea snakes of the subfamily Hydrophiinae are morphologically and ecologically diverse and distributed throughout the Indo-Pacific. Earlier works on the cranial morphology of the Hydrophiinae were mostly on the description of teeth-bearing bones and schematic diagrams of skulls. The present study aims to provide a detailed description of the cranium and mandibular structure of two commonly distributed sea snake species in India, namely Hydrophis schistosus and H. platurus. This study analyzes the variations in the cranial morphology between these two species using thirty-two allometric characters. This study also reveals that various components of the skull vary in shape as compared to their terrestrial Elapid cousins. On comparison among these two species, it was found that there are considerable morphological variations in the length of major bones like ectopterygoid, frontal, mandible, maxilla, nasal, parietal, premaxilla, pterygoid and quadrate. In addition, structural variation in the frontal, parietal, premaxillary, and basisphenoid bones along with variation in all the teeth-bearing structures including maxilla, palatine, pterygoid and dentine have also been noticed. Further, the basisphenoid process which is present in H. schistosus and absent in H. platurus which may have a functional role associated with the dietary specialization in the former species to capture the catfishes that constitute their major prey.


Download data is not yet available.




How to Cite

Mondal, S., Kundu, S., Mohapatra, P. P., & Raghunathan, C. (2023). Comparative Cranial Osteology of <i>Hydrophis schistosus</i> Daudin, 1803 and <i>Hydrophis platurus</i> (Linnaeus, 1766) (Elapidae: Hydrophiinae). Records of the Zoological Survey of India, 123(2S), 261–268.


Ahrenfeldt, R. H. 1955. Two British anatomical studies on American reptiles (1650-1750) II. Edward Tyson: Comparative anatomy of the timber rattle,snake. Herpetologica, 2(l):49-69.

Bogert, C.M. 1943. Dentitional phenomena in cobras and other elapids with notes on adaptive modifications. Bull.Amer.Mus. Nat.Hist.,81(3): 285-360.

Borczyk, B., Paśko, Ł., Kusznierz, J. and Bury, S., 2021. Sexual dimorphism and skull size and shape in the highly specialized snake species, Aipysurus eydouxii (Elapidae: Hydrophiinae). PeerJ, 9, p.e11311.

Bullock, Robert E. and Tanner, Wilmer W. 1966. “A comparative osteological study of two species of Colubridae: (Pituophis and T hamnophis),” Brigham Young University Science Bulletin, Biological Series: Vol. 8 : No. 3 , Article 1.

Cole, F. J. 1944. A history of comparative anatomy. Macmillan, London. Cundall D, Greene HW. (2000). Feeding in snakes. In: Schwenk K (ed) Feeding: form, function, and evolution in Tetrapod vertebrates. Academic Press, San Diego, pp 293–333

Cundall, D. 2000. Drinking in snakes: kinematic cycling and water transport. J Exp Biol 203:2171–2185

Daudin, F. M. 1803. Histoire Naturelle, Générale et Particulière des Reptiles. vol. 7. Paris: Dufart, 436 pp. [publication date fide Harper 1940]

Dunson W.A. 1982. Salinity relations of crocodiles in Florida Bay. Copeia 1982. pp 374–385.

Gegenbaur, C. 1878. Elements of comparative anatomy. Macmillan, London.

Gentilli A, Cardini A, Fontaneto D, Zuffi MAL. 2009. The phylogenetic signal in cranial morphology of Vipera aspis: a contribution from geometric morphometrics. Herpetol J 19:69–77.

Gloyd HK, Conant, R. 1990. Snakes of the Agkistrodon complex: a monographic review. Society for the Study of Amphibians and Reptiles (SSAR), Oxford

Goodrich, E. S. 1930. Studies on the structure and development of vertebrates. Macmillan, London.

Gregory,W.K. 1913. Homology of the ”lacrimal” and the ”alisphenoid” in the recent and fossil reptiles.B ll. Geol. Soc. Amer., 24:241-246.

Günther, A.C.L.G. 1864. The Reptiles of British India. Ray Society, London, xxvii + 452 pp., 28 pls.

Hanken J, Hall BK. 1993. Mechanisms of skull diversity and evolution. In: Hanken J, Hall BK (eds) The skull. Functional and evolutionary mechanisms, vol 3. The University of Chicago Press, Chicago, pp 1–36

Herrel A, Schaerlaeken V, Meyers JJ, Metzger KA, Ross CF. 2007. The evolution of cranial design and performance in squamates: consequences of skull-bone reduction on feeding behavior. Integr Comp Biol 47:107–117. doi:10.1093/icb/icm014

Hoffman, C. K. 1890. Reptilien. In Bronn’s Klassen und Ordnungen des Tier Reich, 6(3) :1420-1465.

Huxley. T. H. 1871. A manual of anatomy of vertebrate animals. J. and A. Churchill, London.

Jollie,M.T. 1960. The head skeleton of the Lizard. Acta Zoologica, 41:1-64.

Kellicott, D.S.1898. The dissection of the Ophidian. Gen.Biol. Supply House, Chicago.

Kharin, V.E., 2004. Review of sea snakes of the genus Hydrophis sensu stricto (Serpentes: Hydrophiidae). Russian Journal of Marine Biology, 30, pp.387-394.

Kharin, V.E., 2007. On the second record of yellow-bellied sea snake Pelamis platurus (Linnaeus, 1766) from Russia. Russian Journal of Herpetology, 14(1), pp.45-49.

Kingsley, J. S. 1917. Outline of comparative anatomy of vertebrates. P. Blakiston, Philadelphia.

Klauber, L. M. 1935. The feeding habits of a sea snake. Copeia 1935:182.

Kramer, E. 1980. Zum Skelett der Aspisviper, Vipera aspis (Linnaeus, 1758). Rev. Suisse Zool. 87:3–16

Kropach, C. 1975. The yellow-bellied sea snake, Pelamis, in the Eastern Pacific. In W. A. Dunson (ed.), The biology of sea snakes, pp. 185-21 3. Univ. Park Press, Baltimore, Maryland.

Mazzotti J, Dunson WA. 1984. Adaptations of Crocodylus acutus and Alligator for life in saline water. Comparative Biochemistry and Physiology 79: 641–646.

Owen, R. 1866. The anatomy of vertebrates. Lomgman, Green and Co., London, 1:53-57.

Romer, A. S. 1956. Osteology of the reptiles. Univ. Chicago Press, Ilinois.

Sedgwick. A. 1905. A student’s text-book of zoology. Swan Sonnenschein and Co., Ltd., London, v, 2,

Sherratt, E., Sanders, K.L., Watson, A., Hutchinson, M.N., Lee, M.S. and Palci, A. 2019. Heterochronic shifts mediate ecomorphological convergence in skull shape of microcephalic sea snakes. Integrative and comparative biology, 59(3), pp.616-624.

Shine R, Olsson MM, Lemaster MP, Moore IT, Mason RT. 2000. Effects of sex, body size, temperature, and location on the antipredator tactics of free-ranging gartersnakes (Thamnophis sirtalis, Colubridae). Behav Ecol 11:239–245. doi:10.1093/beheco/11.3.239

Smith, KK. 1993. The form of the feeding apparatus in terrestrial vertebrates: studies of adaptation and constraint. In: Hanken J, Hall BK (eds) The skull. Functional and evolutionary mechanisms, vol 3. The University of Chicago Press, Chicago, pp 150–196

Smith, M.A. 1926. Monograph on the Sea Snakes. (Hydrophiidae). British Museum, London, xvii + 130 pp.

Ukuwela, K.D., Lee, M.S., Rasmussen, A.R., De Silva, A. and Sanders, K.L., 2017. Biogeographic origins of the viviparous sea snake assemblage (Elapidae) of the Indian Ocean. Ceylon Journal of Science, 46(5).

Versluys, J. 1937. Kranium und visceralskellett der Reptilien, In Bolk et al. Handbuch der vergleichenden anatomic der Wirbeltier, 4:780-7

Voris HK, HH Voris. 1983. Feeding strategies in marine snakes: an analysis of evolutionary, morphological, behavioral and ecological relationships. Am. Zool. 23: 411-425.

Wiedersheim, R., and W. N. Parker. 1907. Comparative anatomy of vertebrates. Macmillan, London.

Williston, S, W. 1925. The osteology of the reptiles. Harvard Univ. Press, Cambridge.

Most read articles by the same author(s)

<< < 1 2 3 > >>