Hydrophis platurus (Linnaeus, 1766)

Rezaie-Atagholipour, Mohsen, Ghezellou, Parviz, Hesni, Majid Askari, Dakhteh, Seyyed Mohammad Hashem, Ahmadian, Hooman & Vidal, Nicolas, 2016, Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman, ZooKeys 622, pp. 129-164 : 140-142

Taxon classification Animalia Squamata Elapidae

Hydrophis platurus (Linnaeus, 1766) Figures 3h, 4f, 12, 13

Anguis platura Linnaeus, 1766: 391.

Hydrus platurus - Werner 1895: 18. -Boulenger 1897: 468.

Pelamis platurus - Volsøe 1939: 23. - Corkill and Cochrane 1965: 495. - Leviton and Anderson 1967: 188. - Gallagher 1971: 31. - Eissa and El-Assy 1975: 129. - Joger 1984: 30. - Leviton and Aldrich 1984: XXIV. - Gasperetti 1988: 323. - Leviton et al. 1992: 126. - Carpenter et al. 1997: 248. - Firouz 1999: 192. - Latifi 2000: 347. - Baldwin and Gardner 2005: 251. - Firouz 2005: 210. - Soorae et al. 2006: 109. - Egan 2007: 163. - Rastegar-Pouyani et al. 2008: 20. - Safaei and Esmaili 2009: 45. - Soorae et al. 2010: 535.

Hydrophis platurus - Kamali 2013: 241. - Safaei-Mahroo et al. 2015: 282.

Material examined.

Gulf of Oman: 1 specimen, Jask and Ras-Meydani, depth 18-50m [(ZMSBUK.HD.26), TL 401, SVL 352, HL 25, HW 10.1, GL 17.7, SNL 3.4, NEL 4.7, ND 34, GBD 38, NSL 10, NSR 39, BSR 46], October and November 2013, collector: M. Rezaie-Atagholipour; 2 specimens, Beris and Pasa-Bandar, depth 20-40m [(ZMSBUK.HD.12), TL 611, SVL 551, HL 34.5, HW 13, GL 22.2, SNL 4.7, NEL 6, ND 27, GBD 63, NSL 9, NV 333; (ZMSBUK.HD.23), TL 690, SVL 618, HL 35.8, HW 17.9, GL 29.7, SNL 5, NEL 6.8, ND 52, GBD 72, NSL 9, NSR 56, BSR 58, NV 330], August 2013, collector: M. Rezaie-Atagholipour.

Diagnosis.

Head narrow; snout elongate (Figures 12-13); 9-10 supralabials, second touches prefrontal scale, four and fifth separated from eye by suboculars or contact eye (Figures 12a, 13a); body short, not stout (Figure 13d); 330-333 small ventral scales [265-367 ( Volsøe 1939)], more or less indistinguishable from adjacent scales at mid-body (Figure 4f).

Coloration.

This species has a unique color pattern making it distinguishable from other sea snakes; dorsal half of head and body black, dark green or dark brown, ventral half of head and body yellow, a markedly sharp contrast between dorsal and ventral portions; tail yellow in ventral portion, spotted or barred in dorsal portion (Figure 13d); sometimes with pale dorsal color.

Size.

Mean TL 567 mm, maximum 690 mm (n = 3); [n = 5, mean TL 449 mm, maximum 565 mm ( Volsøe 1939)].

General distribution.

Indo-Pacific, from east and south of Africa to the west coast of Americas ( Heatwole 1999).

IUCN Red List Category.

Least concern ( IUCN 2016).

Remarks.

Hydrophis platurus is distinguishable from other species in the region by having a unique color pattern (see above). Hydrophis platurus has been known as the only planktonic tetrapod, spending a considerable portion of its life floating at the depth of 20-50 m, but preying on fish at the sea surface by float-and-wait feeding strategy, passively drifting with surface and subsurface marine currents. It has consequently the widest distribution of all squamatan reptiles ( Cook and Brischoux 2014; Hecht et al. 1974; Sheehy III et al. 2012). None of the specimens collected in this project were from the Persian Gulf, although there are records from the Persian Gulf (e.g. Eissa and El-Assy 1975; Gallagher 1971; Soorae et al. 2006; Volsøe 1939; Werner 1895).