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Corresponding author: Mohsen Rezaie-Atagholipour ( rezaie1986@gmail.com ) Corresponding author: Parviz Ghezellou ( p.ghezellou@gmail.com ) Corresponding author: Nicolas Vidal ( nvidal@mnhn.fr ) Academic editor: Robert Jadin
© 2016 Mohsen Rezaie-Atagholipour, Parviz Ghezellou, Majid Askari Hesni, Seyyed Mohammad Hashem Dakhteh, Hooman Ahmadian, Nicolas Vidal.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Rezaie-Atagholipour M, Ghezellou P, Hesni MA, Dakhteh SMH, Ahmadian H, Vidal N (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: 129-164. https://doi.org/10.3897/zookeys.622.9939
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The Persian Gulf is known as the westernmost distribution limit for sea snakes, except for Hydrophis platurus (Linnaeus, 1766) that reaches southeastern Africa. Previous identification guides for sea snakes of the Persian Gulf and its adjacent waters in the Gulf of Oman were based on old data and confined mostly to written descriptions. Therefore, a series of field surveys were carried out in 2013 and 2014 through Iranian coastal waters of both gulfs to provide a comprehensive sampling of sea snakes in the area. This paper presents an illustrated and updated checklist and identification tool for sea snakes in the Persian Gulf and Gulf of Oman, which are based on new material and a review of the literature. This checklist includes ten species of marine hydrophiines, of which one, Microcephalophis cantoris (Günther, 1864), is a new record for the area. All specimens examined herein are deposited and available at the Zoological Museum of Shahid Bahonar University of Kerman, Kerman province, Iran.
Indian Ocean, new record, reptiles, Serpentes , venomous, viviparous
All true sea snakes of the subfamily Hydrophiinae share a common ancestor dating back to approximately six million years ago, although the majority of the extant lineages have diversified in the last three and half million years (
The Persian Gulf is a semi-enclosed shallow marine environment (mean depth ca. 35 meters) lying in a subtropical and hyper-arid region in the northwestern Indian Ocean. This water body is considered a young sea (~15,000 years) with impoverished species biodiversity. Biota living in the Gulf must adapt to high temperatures and a hypersaline environment (
Populations of sea snakes in the Persian Gulf are peculiar for two main reasons. First, because the Gulf is known as the westernmost extent of sea snakes (with the exception of H. platurus, which is also found in the east coast of Africa) (
Nonetheless, our knowledge about the sea snake diversity in the Persian Gulf and its adjacent waters is based on older studies (e.g.
The sea snakes examined herein were collected from the Iranian coastal waters of the Persian Gulf and Gulf of Oman (Figure
Sea snakes were collected from by-catch of fishing trawlers in coastal waters of Bushehr Province in the western Persian Gulf, Jask and Ras-Meydani (Hormozgan Province) in the western Gulf of Oman and Beris and Pasa-Bandar (Sistan-O-Baluchestan Province) in the eastern Gulf of Oman in 2013 (Figure
A total of 14 characters was examined: each specimen was measured for total length (TL), snout-vent length (SVL), head length (HL), head width (HW), gap length (GL), snout to nostril length (SNL), nostril to eye length (NEL), neck diameter (ND) and greatest body diameter (GBD). Furthermore, number of supralabials (NSL), number of scale rows on the neck (NSR), number of scale rows on the body (BSR), number of ventrals (NV), and number of bands (NB) were also recorded for each specimen. SVL, HW, GL, SNL and NEL were measured following
Some external diagnostic characters (e.g. coloration patterns, number, size and shape of head shields, and body and ventral scales) were used to make updated and easy to use identification keys, which allow users to identify sea snakes in the field without the need of a binocular.
Morphological characters are presented using abbreviations (see above). Data of all measurements are in mm. Due to great interspecific and intraspecific variations in external characters of sea snakes (
1 | Head extremely small; neck markedly slender; usually 5–6 supralabials; usually less than 25 scale rows on neck (Figures |
Microcephalophis |
– | Head and neck not as in 1; usually more than 6 supralabials; usually more than 25 scale rows on neck (Figures |
Hydrophis |
1 | Tip of rostral decurved and pointed (beaked-shaped; Figures |
Hydrophis schistosus |
– | Tip of rostral curved and dentate (Figures |
2 |
2 | Tip of rostral markedly tridentate (Figures |
3 |
– | Tip of rostral markedly or slightly unidentate (Figures |
4 |
3 | Ventrals on anterior part of body markedly large, wide and rectangular in shape (Figure |
Hydrophis viperinus |
– | Ventrals on anterior part of body medium size, more or less hexagonal in shape (Figure |
Hydrophis curtus |
4 | Markedly sharp contrast in colors of dorsal and ventral portions of head and body, dark brown or black dorsally, yellow ventrally (Figure |
Hydrophis platurus |
– | Not colored as in 4, usually banded body (Figures |
5 |
5 | Body bands narrower than light interspaces (Figure |
Hydrophis spiralis |
– | Body bands as wide as or wider than light interspaces (Figures |
6 |
6 | Head slightly small; body elongate; body bands broader dorsally tapering to points in lateral sides (Figures |
7 |
– | Head of medium size; body slightly stout; rhomboidal or rectangular dark body bands clearly distinct with light narrow interspaces (Figure |
Hydrophis ornatus |
7 | Scales on thickest part of body juxtaposed or feebly imbricate, more or less hexagonal or quadrangular in shape; total length rarely exceeding one meter in adults (Figures |
Hydrophis lapemoides |
– | Scales on thickest part of body more or less imbricate with bluntly pointed tips; total length more than one meter in adults (Figures |
Hydrophis cyanocinctus |
Rostrals and mentals of sea snakes of the genus Hydrophis in the Persian Gulf and Gulf of Oman: a tip of rostral decurved, pointed and beaked shaped, mental narrow, elongate and dagger-shaped (Hydrophis schistosus) b and c tip of rostral markedly tridentate, mental short and triangulate (H. viperinus and H. curtus, respectively) d tip of rostral markedly unidentate, mental short and triangulate (H. ornatus) e–h tip of rostral slightly unidentate, mental short and triangulate (H. ornatus, H. spiralis, H. cyanocinctus and H. platurus, respectively).
Various shapes of ventrals on the mid-body of sea snakes of the genus Hydrophis in the Persian Gulf and Gulf of Oman: a wide and enlarged, more or less rectangular in shape (Hydrophis viperinus) b medium size, distinguishable from the adjacent scales, more or less hexagonal in shape (H. curtus) c and d small and slightly distinguishable from adjacent scales (H. ornatus and H. lapemoides, respectively) e and f small and more or less indistinguishable from adjacent scales (H. schistosus and H. platurus, respectively).
1 | Less than 270 ventrals; prefrontal scale usually in contact with second supralabial (Figure |
Microcephalophis gracilis |
– | More than 400 ventrals; prefrontal scale usually in contact with third supralabial (Figure |
Microcephalophis cantoris |
Hydrophis schistosus Daudin, 1803: 386.
Enhydrina
schistosa
-
Hydrophis
schistosus
-
Persian Gulf: 1 specimen, Larak Island [(ZMSBUK.HD.58), TL 971, SVL 857, HL 29.6, HW 12.6, GL 18.4, SNL 5.3, NEL 3.1, ND 52, GBD 100, NSL 7, NSR 47, BSR 57, NV 301], February 2014, collector: M. Ghavasi.
Gulf of Oman: 8 specimens, Jask and Ras-Meydani, depth 18–50m [(ZMSBUK.HD.14), TL 1147, SVL 1008, HL 29.4, HW 14.5, GL 20.8, SNL 5.3, NEL 3.7, ND 55, GBD 95, NSL 8, NSR 48, BSR 55, NV 315; (ZMSBUK.HD.21), TL 1180, SVL 1064, HL 31.2, HW 12.3, GL 22.4, SNL 5.4, NEL 3.4, ND 54, GBD 109, NSL 9, NSR 51, BSR 57, NV 303; (ZMSBUK.HD.25), juvenile, TL 508, SVL 451, HL 17.9, HW 7.7, GL 12, SNL 2.9, NEL 1.3, ND 26, GBD 39, NSL 8, NSR 51, BSR 59, NV 344; (ZMSBUK.HD.41), TL 1093, SVL 977, HL 30.5, ND 51, GBD 95, NSL 8, BSR 60; (ZMSBUK.HD.45), TL 1057, SVL 943, HL 31.3, HW 18, GL 20.5, SNL 4.4, NEL 3.9, ND 48, GBD 96, NSL 7, NSR 47, BSR 60, NV 323; (ZMSBUK.HD.50), TL 1172, SVL 1064, HL 36.7, HW 19.3, GL 23.7, SNL 5.5, NEL 4.6, ND 60, GBD 105, NSL 8, NSR 51, BSR 61, NV 316; (ZMSBUK.HD.51), TL 932, SVL 823, HL 28.4, HW 13.7, GL 17.7, SNL 5.6, NEL 3.4, ND 45, GBD 98, NSL 8, NSR 50, BSR 61, NV 325; (ZMSBUK.HD.52), TL 1230, SVL 1093, HL 35.2, HW 16.6, GL 23.5, SNL 4.8, NEL 4.4, ND 62, GBD 116, NSL 8, NSR 53, BSR 65, NV 340], October and November 2013, collector: M. Rezaie-Atagholipour; 3 specimens, Jask, mangrove swamps, depth 1–3m [(ZMSBUK.HD.27), TL 966, SVL 855, HL 28.3, HW12.3, GL 19.7, SNL 4.9, NEL 3.7, ND 44, GBD 90, NSL9, NSR 52, BSR 59, NV 327; (ZMSBUK.HD.29), TL 1080, SVL 947, HL 30.5, HW 18.1, GL 17, SNL 5.6, NEL 4.1, ND 50, GBD 80, NSL 9, NSR 40, BSR 58, NV 348; (ZMSBUK.HD.62), TL 1032, SVL 907, HL 28.5, HW 16, GL 20.1, SNL 5.2, NEL 4.5, ND 52, GBD 88, NSL 8, NSR 47, BSR 59, NV 327], December 2013, collector: M. Rezaie-Atagholipour; 2 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.49), TL 1044, SVL 928, HL 30.8, HW 12.7, GL 19.3, SNL 5, NEL 3.7, ND 50, GBD 105, NSL 7, NSR 51, BSR 64, NV 302; (ZMSBUK.HD.53), TL 1095, SVL 955, HL 31.9, HW 14.7, GL 19.4, SNL 2.5, NEL 4.2, ND 50, GBD 95, NSL 8, NSR, BSR, NV, NB], August 2013, collector: M. Rezaie-Atagholipour.
Head of medium size; rostral beaked-shaped, elongate with decurved and pointed tip (Figures
Gray or dark olive dorsally, whitish ventrally; body rings developed in juveniles but paler or absent in adults (Figure
Mean TL 1036 mm, maximum 1230 mm (n = 14) [n = 3, maximum TL 1350 mm (
Indo- West Pacific, from the Persian Gulf to Australia (
Least concern (
Hydrophis schistosus is distinct from other species in the Persian Gulf and Gulf of Oman due to its beaked-shaped rostral and dagger-shaped mental. Results of our field surveys showed that the species is more abundant in the Gulf of Oman rather than in the Persian Gulf. This is supported by other studies as eight specimens have been hitherto examined from the Gulf of Oman (
Thalassophis viperina Schmidt, 1852: 79.
Thalassophis
viperina
-
Hydrophis
jayakari
-
Hydrophis
plumbea
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Distira
viperina
-
Praescutata
viperina
-
Hydrophis
viperinus
-
Gulf of Oman: 2 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.20), TL 737, SVL 656, HL 19.1, HW 12.6, GL 14.8, SNL 3, NEL 3, ND 35, GBD 67, NSL 8, NSR 29, BSR 47, NV 250; (ZMSBUK.HD.43), TL 740, SVL 657, HL 18.9, HW 14.9, GL 13.3, SNL 3.9, NEL 2.8, ND 38, GBD 68, NSL 7, NSR 30, BSR 43, NV 265], August 2013, collector: M. Rezaie-Atagholipour.
Head large, short and depressed (Figures
Dark gray dorsally, dirty white ventrally; with or without pale body bands broadest dorsally; tip of tail usually black (Figure
Maximum TL 740 mm (n = 2); [n = 8, mean TL 662 mm, maximum TL 780 mm (
Indian Ocean, from the Persian Gulf to Malay Archipelago (
Least concern (
Hydrophis viperinus is distinct from other sea snakes in the Persian Gulf and Gulf of Oman by having markedly rectangular-shaped and enlarged ventrals on the anterior part of the body.
Hydrus curtus Shaw, 1802: 562.
Enhydris
curtus
-
Lapemis
curtus
-
Hydrophis
curtus
-
Persian Gulf: 8 specimens, Bushehr Province [(ZMSBUK.HD.1), TL 915, SVL 831, HL 32.9, HW 24.9, GL 22.9, SNL 7.9, NEL 4.8, ND 74, GBD 130, NSL 8, NSR 32, BSR 39, NV 158, NB 39; (ZMSBUK.HD.2), TL 900, SVL 805, HL 34, HW 20.5, GL 23, SNL 7.3, NEL 5.4, ND 80, GBD 130, NSL 8, NSR 29, BSR 37, NV 187, NB 45; (ZMSBUK.HD.5), TL 835, SVL 755, HL 31.5, HW 16.8, GL 26, SNL 7.1, NEL 4.6, ND 62, GBD 95, NSL 8, NSR 30, BSR 39, NV 165, NB 47; (ZMSBUK.HD.11), TL 852, SVL 751, HL 30.3, HW 16.8, GL 22.2, SNL 5.8, NEL 4.5, ND 72, GBD 107, NSL 9, NSR 28, BSR 33, NV 147, NB 50; (ZMSBUK.HD.15), TL 1008, SVL 910, HL 34.2, HW 19.2, GL 23.9, SNL 6.6, NEL 5, ND 80, GBD 125, NSL 8, NSR 31, BSR 39, NV 185, NB 55; (ZMSBUK.HD.17), TL 869, SVL 781, HL 28.7, HW 15.8, GL 20.7, SNL 6, NEL 4.3, ND 61, GBD 75, NSL 7, NSR 24, BSR 36, NV 153, NB 48; (ZMSBUK.HD.47), TL 797, SVL 716, HL 30.5, HW 16.9, GL 19.7, SNL 5.6, NEL 4.6, ND 50, GBD 62, NSL 8, NSR 30, BSR 37, NV 158, NB 45; (ZMSBUK.HD.48), TL 716, SVL 642, HL 28.4, HW 14.8, GL 18.4, SNL 4.3, NEL 4.2, ND 55, GBD 85, NSL 8, NSR 33, BSR 43, NV 199, NB 46], September 2013, collector: M. Rezaie-Atagholipour; 1 specimen, Larak Island [(ZMSBUK.HD.61), TL 783, SVL 700, HL 28.5, HW 15.3, GL 20.3, SNL 5, NEL 4.7, ND 62, GBD 95, NSL 8, NSR 32, BSR 42, NV 200, NB 51], February 2014, collector: M. Ghavasi.
Gulf of Oman: 6 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.8), TL 855, SVL 772, HL 34.1, HW 21.6, GL 21.5, SNL 5.43, NEL 4.91, ND 70, GBD 93, NSL 7, NSR 28, BSR 34, NV 158; (ZMSBUK.HD.18), TL 960, SVL 865, HL 34, HW 16.5, GL 25, SNL 5.8, NEL 5.7, ND 72, GBD 115, NSL 7, NSR 32, BSR 37, NV 157; (ZMSBUK.HD.19), TL 825, SVL 753, HL 28.9, HW 18.1, GL 19.2, SNL 4.8, NEL 4.5, ND 58, GBD 100, NSL 8, NSR 33, BSR 40, NV201, NB 47; (ZMSBUK.HD.44), TL 1015, SVL 925, HL 40.9, HW 27.7, GL 25.6, SNL 6.6, NEL 5.3, ND 73, GBD 99, NSL 8, NSR 34, BSR 43, NV 197, NB 49; (ZMSBUK.HD.57), TL 745, SVL 674, HL 29.7, HW 17.6, GL 20.3, SNL 3.9, NEL 3.6, ND 57, GBD 85, NSL 7, NSR 33, BSR 38, NV 185, NB 50; (ZMSBUK.HD.60), TL 965, SVL 872, HL 32.7, HW 18.1, GL 23.4, SNL 5.6, NEL 5.5, ND 65, GBD 117, NSL 8, NSR31, BSR 39, NV 174, NB 51], August 2013, collector: M. Rezaie-Atagholipour.
Head large (Figure
Three color patterns observed in this study: 1- usually gray dorsally, gray-whitish ventrally with pale gray dorsal bands (Figures
Mean TL 716 mm, maximum 1015 mm (n = 15); [n = 12, mean TL 606 mm, maximum TL 860 mm (
Indo- West Pacific, from the Persian Gulf to Australia (
Least concern (
In the Persian Gulf and Gulf of Oman, H. curtus may be roughly confused with H. ornatus at a glance. Hydrophis curtus however can be quickly distinguished from H. ornatus by having parietals divided into small shields and laterally fused dorsal bands, zigzag in form, versus clearly distinguishable dorsal bands in H. ornatus.
Anguis platura Linnaeus, 1766: 391.
Hydrus
platurus
-
Pelamis
platurus
-
Hydrophis
platurus
-
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, SVL618, 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.
Head narrow; snout elongate (Figures
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
Mean TL 567 mm, maximum 690 mm (n = 3); [n = 5, mean TL 449 mm, maximum 565 mm (
Indo-Pacific, from east and south of Africa to the west coast of Americas (
Least concern (
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 (
Hydrus spiralis Shaw, 1802: 564.
Hydrus
temporalis
-
Hydrus
robusta
-
Hydrophis
spiralis
-
Hydrophis
spiralis
spiralis
-
Gulf of Oman: 1 specimen, Jask, depth 1–3m [(ZMSBUK.HD.55), TL 1925, SVL 1775, HL 44.3, HW 20.6, GL 28, SNL 7.5, NEL 5.8, ND 67, GBD 90, NSL 7, NSR 30, BSR 38, NV 387, NB 61], December 2013, collector: M. Rezaie-Atagholipour.
Head of medium size (Figure
Yellowish body with 61 [30–60 more or less (
TL 1925 mm (n = 1); [n = 4, mean TL 1587 mm; maximum TL 1984 mm (
Indian Ocean, from the Persian Gulf to Malay Archipelago (
Least concern (
Hydrophis spiralis is distinguishable from other species in the area by its yellow body and narrow black rings (narrower than yellow interspaces). This species is the longest among all marine hydrophiines (
Aturia ornata Gray, 1842: 61.
Hydrophis
elliotti
-
Distira
ornata
-
Hydrophis
ornatus
ornatus
-
Hydrophis
ornatus
-
Persian Gulf: 3 specimens, Bushehr Province [(ZMSBUK.HD.10), TL 813, SVL 722, HL 26, HW 16.7, GL 18.8, SNL 4.9, NEL 3.9, ND 53, GBD 80, NSL 7, NSR 35, BSR 42, NB 41; (ZMSBUK.HD.13), TL 879, SVL 791, HL 28.1, HW 15, GL 12.5, SNL 4.2, NEL 4, ND 55, GBD 89, NSL 7, NSR 40, BSR 44, NV 302, NB 46; (ZMSBUK.HD.16), TL 1200, SVL 1072, HL 36.6, HW 23.7, GL 27.6, SNL 6, NEL 5.2, ND 74, GBD 157, NSL 7, NSR 41, BSR 50, NV 306, NB 53], September 2013, collector: M. Rezaie-Atagholipour.
Gulf of Oman: 3 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.3), TL 1015, SVL 908, HL 32.9, HW 30, GL 21.9, SNL 6.9, NEL 5.2, ND 68, GBD 110, NSL 8, NSR 37, BSR 42, NV 251, NB 51; (ZMSBUK.HD.7), TL 985, SVL 800, HL 32.6, HW 19.5, GL 23, SNL 6.5, NEL 5.2, ND 65, GBD 97, NSL 7, NSR 38, BSR 48, NV 260, NB 51; (ZMSBUK.HD.59), TL 1035, HL 33.9, HW 20.1, GL 24.1, SNL 5, NEL 5.3, ND 65, GBD 140, NSL 8, NSR 34, BSR 48, NV 286, NB 49], August 2013, collector: M. Rezaie-Atagholipour.
Head of medium size (Figure
Body dirty white (Figure
Mean TL 988 mm, maximum 1200 mm (n = 6); [n = 1, TL 885 mm (
Indo-West Pacific, from the Persian Gulf to Australia (
Least concern (
In the Persian Gulf and Gulf of Oman, H. ornatus may be roughly misidentified with H. curtus (for more details see remarks of H. curtus).
Hydrophis cyanocinctus Daudin, 1803: 383.
Hydrophis
cyanocinctus
-
Hydrophis
cyanocincta
-
Distira
cyanocincta
-
Persian Gulf: 1 specimen, Bushehr Province [(ZMSBUK.HD.9), TL 1185, SVL 1075, HL 23.9, HW 12.5, GL 13.4, SNL 4, NEL 3.6, ND 44, GBD 67, NSL 8, NSR 28, BSR 41, NV 359, NB 54], September 2013, collector: M. Rezaie-Atagholipour.
Gulf of Oman: 3 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.4), TL 1275, SVL 1160, HL 25.3, HW 10.7, GL 13.3, SNL 5, NEL 4.4, ND 38, GBD 82, NSL 8, NSR 29, BSR 39, NV 332, NB 56; (ZMSBUK.HD.6), TL 1447, SVL 1332, HL 27.3, HW 16.8, GL 17.9, SNL 4.6, NEL 3.2, ND 24, GBD 105, NSL 8, NSR 29, BSR 40, NV 339, NB 53; (ZMSBUK.HD.56), TL 1065, SVL 463, HL 14.8, HW 10.5, GL 13.9, SNL 3.7, NEL 2.5, ND 38, GBD 67, NSL 8, NSR 25, BSR 39, NV 300, NB 51], August 2013, collector: M. Rezaie-Atagholipour.
Head slightly small (Figure
Body dark olive, grayish, or dirty white, dorsally darker and ventrally paler; 51–56 [44–54 (
Mean TL 1243 mm, maximum 1447 mm (n = 4); [n = 7, mean TL 1195 mm, maximum TL 1495 mm (
Indo-West Pacific, from the Persian Gulf to Japan (
Least concern (
In the Persian Gulf and Gulf of Oman, juveniles of Hydrophis cyanocinctus (smaller than one meter) are morphologically close to H. lapemoides. In this case, focusing on the shape of scales in the thickest part of the body (with rounded or bluntly pointed tips versus more or less hexagonal or quadrangular in shape in H. lapemoides) is helpful (see diagnostic features for both species). But adults exceed one meter, which is very rare in H. lapemoides.
Aturia lapemoides Gray, 1849: 46.
Distira
lapemidoides
-
Hydrophis
lapemoides
-
Chitulia
lapemoides
-
Gulf of Oman: 1 specimen, Jask and Ras-Meydani, depth 18–50m [(ZMSBUK.HD.40), TL 775, SVL 702, HL 19, HW 9.2, GL 11.7, SNL 3.4, NEL 2.4, ND 30, GBD 65, NSL 7, NSR 30, BSR 43, NB 45], October and November 2013, collector: M. Rezaie-Atagholipour.
Head slightly small (Figure
Body olive-whitish, dirty white, darker dorsally and paler ventrally; [41–55 (
TL 775 mm (n = 1); [n = 8, mean TL 781 mm, maximum TL 895 mm (
Indian Ocean, from the Persian Gulf to Malay Archipelago (
Least concern (
Hydrophis lapemoides may be easily misidentified with juveniles H. cyanocinctus in the Persian Gulf and Gulf of Oman (for more details see remarks on H. cyanocinctus).
Hydrus gracilis Shaw, 1802: 560.
Microcephalophis
gracilis
gracilis
-
Microcephalophis
gracilis
-
Hydrophis
gracilis
gracilis
-
Hydrophis
gracilis
-
Gulf of Oman: 11 specimens, Beris and Pasa-Bandar, depth 20–40m [(ZMSBUK.HD.31), TL 968, SVL 878, HL 13.1, HW 5.3, GL 7.7, SNL 3.1, NEL 1.1, ND 24, GBD 66, NSL 5, NSR 19, BSR 33, NV 237, NB 21; (ZMSBUK.HD.32), TL 830, SVL 757, HL 116, HW 4.4, GL 7, SNL 2.7, NEL 1.2, ND 19, GBD 66, NSL 6, NSR 18, BSR 31, NV 269, NB 43; (ZMSBUK.HD.33), TL 978, SVL 893, HL 13.1, HW 5.9, GL 7.8, SNL 3.4, NEL 1.9, ND 20, GBD 54, NSL 6, NSR 15, BSR 29, NV245, NB 59; (ZMSBUK.HD.34), TL 900, SVL 821, HL 12.3, HW 5.2, GL 7.9, SNL 2.8, NEL 1.4, ND 23, GBD 67, NSL 6, NSR 18, BSR 29, NV 253, NB 55; (ZMSBUK.HD.35), TL 893, SVL 821, HL 12.1, HW 6.3, GL 9, SNL 3, NEL 1.8, ND 20, GBD 55, NSL 6, NSR 17, BSR 31, NV 223, NB 20; (ZMSBUK.HD.36), TL 900, SVL 820, HL 12.2, HW 5.1, GL 9, SNL 3.6, NEL 1.7, ND 22, GBD 58, NSL 6, NSR 18, BSR 31, NV 231, NB 51; (ZMSBUK.HD.37), TL 957, SVL 870, HL 12.5, HW 5.7, GL 8.5, SNL 3.5, NEL 1.4, ND 20, GBD 50, NSL 6, NSR 19, BSR 32, NV 264, NB 46; (ZMSBUK.HD.38), TL860, SVL 787, HL 12.3, HW 5.4, GL 7.7, SNL 3, NEL 1.5, ND 20, GBD 60, NSL 6, NSR 19, BSR29, NV 229, NB 27; (ZMSBUK.HD.39), TL 935, SVL 847, HL 12.8, HW 5.7, GL 8, SNL 3.4, NEL 2.2, ND 22, GBD 78, NSL 6, NSR 19, BSR 30, NV 229, NB 41; (ZMSBUK.HD.46), TL 827, SVL 752, HL 12.7, HW 5.6, GL 9, SNL 3.4, NEL 1.5, ND 18, GBD 62, NSL 6, NSR 19, BSR 30, NV 242, NB 48; (ZMSBUK.HD.54), TL 922, SVL 837, HL 13.2, HW 5.9, GL 8.9, SNL 3.2, NEL 1.4, ND 20, GBD 67, NSL 6, NSR 19, BSR 31, NV 246, NB 53], August 2013, collector: M. Rezaie-Atagholipour.
Head extremely small (Figure
Gray to dark gray dorsally, gray-whitish ventrally, darker anteriorly than posteriorly; 20–59 black bands broader dorsally; bands on necks and anterior part of body are black and merge each other only ventrally or ventrally and dorsally (Figure
Mean TL 906 mm, maximum 978 mm (n = 11); [n = 9, mean TL 865.5 mm, maximum TL 1030 mm (
Indo- West Pacific, from the Persian Gulf to Australia (
Least concern (
Microcephalophis gracilis and the other Small-headed Sea Snake, M. cantoris, recorded here for the first time in the area (see below), are easily distinguishable from other species in the region by having an extremely small head and slender neck. However, these two species may be confused with each other at a glance. Microcephalophis gracilis is distinguishable from M. cantoris by having less number of ventrals (223–269 versus 404–468 in M. cantoris). All material examined in this study was collected from eastern Gulf of Oman.
Hydrophis cantoris Günther, 1864: 374.
Gulf of Oman: 1 specimen, Jask and Ras-Meydani, depth 18–50m [(ZMSBUK.HD.), TL 1124, SVL 992, HL 33.5, HW 12.3, GL 20.2, SNL 5.1, NEL 4.4, ND 51, GBD 101, NSL 6, NSR 24, BSR 41, NV 446], October and November 2013, collector: M. Rezaie-Atagholipour.
Head extremely small and pointed (Figure
Head yellowish; neck and body dark olive dorsally, yellowish ventrally; dorsal portion of body uniform in color and not banded; neck with the rings paler dorsally and black ventrally (Figure
TL 1124 mm (n = 1) [1450 mm in males and 1880 mm in females (
Indian Ocean, from the Gulf of Oman to Malay Archipelago.
Data deficient (
It is the first record of M. cantoris in this area. By this record, westernmost extent of M. cantoris expands from Pakistan to the Gulf of Oman.
This study is dedicated to the memory of the late Iranian herpetologist and toxinologist, Dr. Mahmood Latifi. This study benefited from the financial support (Grant Number: IRA/SGP/OP5/Y3/STAR/BD/13/12-188) and knowledge material of Iranian UNDP/GEF/SGP. We are indebted to Laleh Daraie and Fariba Aghakhani, coordinators of Iranian UNDP/GEF/SGP, for their timely and great support. We warmly thank Reza Naderloo and Vassili Papastavrou for their valuable comments on the first draft of the manuscript. We are also very grateful to Robert Jadin, Bryan Fry, François Brischoux and an anonymous reviewer for reviewing the submitted manuscript. We also kindly thank Patrick David for his help with nomenclatural issues. We wish to thank Bahram Zehzad for providing some critical references for us. Thanks to Mohammad Ghavasi and Rima Jabado for their helpful logistical assistance. We also wish to thank Mehdi Iranmanesh, Abbas Motlaghnejad and Fazel Fazlabadi for their timely and helpful laboratory assistance.