Sea snakes in Australian waters (Serpentes: subfamilies Hydrophiinae and Laticaudinae) - a review with an updated identification key Author Rasmussen, Arne Redsted The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation. Esplanaden 34 DK- 1264, Copenhagen K, Denmark. E-mail: arr @ kadk. dk Author Sanders, Kate Laura School of Earth and Environmental Science. University of Adelaide, Adelaide, South Australia 5000, Australia. Author Guinea, Michael L. School of Environmental. Charles Darwin University, Darwin, Northern Territories 0909, Australia. Author Amey, Andrew P. Queensland Museum. PO Box 3300, South Brisbane BC. Queensland 4101, Australia. E-mail: andrew. amey @ qm. qld. gov. au text Zootaxa 2014 2014-10-02 3869 4 351 371 journal article 10.11646/zootaxa.3869.4.1 1175-5326 4947280 8F80DD5E-F5FC-40DF-BCE5-C404FA7A6577 A key to the genus Hydrophis and Microcephalophis gracilis 1. A Elongated mental shield several times longer than broad ( Fig.9 left)...................................... H. zweifeli B Mental shield not much longer than broad ( Fig.9 right)....................................................... 2. 2. A Ventrals (except on the throat) divided into pairs of overlapping scales ( Fig.10 top)......................... H. stokesii B Ventrals in the posterior part of body divided into pairs of not overlapping scales ( Fig.10 bottom).. Microcephalophis gracilis C Not as above........................................................................................ 3. 3. A Blunt spines on rear edge of some of the head shields ( Fig.11 )........................................... H. peronii B Not as above........................................................................................ 4. 4. A Head elongated with snout bill-like and flattened, very wide gape ( Fig.12 ), the normal colour pattern is yellow on ventral side and black on dorsal side........................................................................ H. platurus B Not as above........................................................................................ 5. 5. A Ventrals very small and difficult to distinguish, scales in the lowermost scale rows on flanks enlarged compared to dorsal scales ( Fig.13 )................................................................................. H. curtus B Not as above........................................................................................ 6. 6. A Less than 275 ventrals and less than 30 scale rows around neck................................................ 7. B Not as above........................................................................................ 8. 7. A Between bands and on the sides two or three series of spots or dark-edged markings, head very small and body compressed posteriorly ( Fig. 14 )......................................................................... H. macdowelli B Not as above........................................................................................ 8. 8. A Less than 25 scale rows around neck and more than 70 dark cross bands on body and tail....................... H. vorisi B Not as above........................................................................................ 9. 9. A Less than 275 ventrals and less than 44 scale rows around body............................................... 10. B Not as above....................................................................................... 11. 10. A Less than 38 bands on body and small dark spots on the sides............................................. H. major B Not as above....................................................................................... 11. 11. A Less than 37 scale rows around body, less than 320 ventrals and more than 45 bands on body and tail................. 12. B Not as above....................................................................................... 13. 12. A Between 57 and 69 bands on body and tail.......................................................... H. belcheri B Between 46 and 56 bands on body and tail.......................................................... H. donaldi 13. A More than 345 ventrals and spots on the flanks and between bands ( Fig. 15 )............................... H. elegans B Not as above....................................................................................... 14. 14. A Less than 285 ventrals................................................................................ 15. B Not as above....................................................................................... 16. 15. A Less than 30 scale rows around neck and more than 41 scale rows around body............................. H. laboutei B Not as above....................................................................................... 16. 16 A More than 50 scale rows around body and one or two rows of regular black pentagonal markings on the side, primary colour dark brown to black ( Fig. 16 ).................................................................. H. czeblukovi B Not as above....................................................................................... 17. 17. A More than 30 scale rows around neck and body with ocelli on the sides, ground colour white ( Fig.17 ).......... H. ocellatus B Not as above....................................................................................... 18. FIGURE 9. Elongated mental shield several times longer than broad (left): H. zweifeli . Mental shield not much longer than broad (right). FIGURE 10. Ventrals (except on the throat) divided into pairs of overlapping scales (top): H. stokesii . Ventrals on the posterior part of the body divided into pairs of not overlapping scales (bottom): Microcephalophis gracilis . FIGURE 11. Blunt spines on rear edge of some of the head shields: H. peronii . FIGURE 12. Head elongated with snout bill-like and flattened, very wide gape: H. platurus . FIGURE 13. Scales in the lowermost scale rows on flanks enlarged compared to dorsal scales: H. curtus . FIGURE 14. Two or three series of spots or dark-edged markings between dark bands, head very small and body compressed posteriorly: H. macdowelli (juvenile pictured). FIGURE 15. Spots on the flanks and between the bands: H. elegans . FIGURE 16. One or two rows of regular black pentagonal markings on the side, primary colour dark brown or black: H. czeblukovi . FIGURE 17. Body with ocelli on the sides, ground colour white: H. ocellatus . 18. A More than 30 scale rows around neck, ground colour not yellow and more than 12 maxillary teeth behind fang H. caerulescens B Not as above....................................................................................... 19. 19. A Head small and neck elongated and body more than 3 times as broad as head.................................... 20. B Not as above....................................................................................... 22. 20. A A white ring around the eye and less than 5 maxillary teeth behind fang.................................... H. kingii B Not as above....................................................................................... 21. 21. A Less than 38 scale rows around neck.............................................................. H. coggeri B More than 38 scale rows around neck.............................................................. H. atriceps 22. A More than 40 bands on body and tail............................................................. H. pacificus B Less than 40 bands on body and tail............................................................... H. coggeri