[Herpetology • 2017] Hydrophis platurus xanthos • A New Subspecies of Sea Snake from Golfo Dulce, Costa Rica

Hydrophis platurus xanthos 

Bessesen & Galbreath, 2017

ambush posture; floating at the sea surface at night in a sinusoidal shape, head below, mouth agape. 

  DOI:  10.3897/zookeys.686.12682 

Abstract

We describe a distinctive new subspecies of sea snake from the occasionally anoxic inner-basin waters of Golfo Dulce, Costa Rica, based on combined data garnered between 2010 and 2017 for 154 specimens, 123 free-ranging and 31 museum-held. The yellow sea snake, Hydrophis platurus xanthos Bessesen & Galbreath, subsp. n., is diagnosed by a notably smaller body size and nearly uniform yellow coloration, which contrasts with the black and yellow striae and tail spots or bands typical of the species. Within the modest geographic range (circa 320 km2), nearly all specimens possess both diagnostic character states. Bathymetrics appear to restrict genetic flow between this allopatric population and conspecifics in the broader Eastern Pacific. In perspicuous contrast to typical H. platurus, H. p. xanthos shows no association with drift lines, and feeds at night in turbulent waters, assuming a sinusoidal ambush posture never previously reported for the species. This evolutionarily significant unit (ESU) warrants taxonomic recognition and active protection.

Keywords: Golfo Dulce, Costa Rica, sea snake, yellow color morph, platurus, type specimens, taxonomy

Figure 2: Hydrophis platurus xanthos sharply contrasts typical H. platurus in color, body size and behavior.
A Scaled size comparison of yellow sea snake, TL 43 cm (left), and yellow-bellied sea snake, TL 69 cm (right; note the use of Vetrap as a calming mask and sickly condition of the specimen) B ambush posture of H. p. xanthos; floating at the sea surface at night in a sinusoidal shape, head below, mouth agape C although predominantly yellow, xanthic individuals often possess black spots along the dorsum.

  

Hydrophis platurus xanthos subsp. n.

Diagnosis: Here we describe a new, allopatric subspecies, Hydrophis platurus xanthos subsp. n., or yellow sea snake, from the inner basin of Costa Rica’s Golfo Dulce. The new subspecies is diagnosed based on a dramatic color character state, as well as by a marked difference in body size. Aspects of behavior also appear to be unique.

Etymology: From Greek xanthos, “yellow,” to highlight a diagnostic feature of this subspecies.

Geographic distribution: The breeding population of Hydrophis platurus xanthos appears confined to approximately 320 sq.km. in the northern half of the Golfo Dulce, Costa Rica. A spatial gap up to 22 km separates the yellow sea snakes from the usually bi- or tricolored oceanic population, and appears to restrict genetic exchange (Bessesen 2012, Fig. 1).

Conclusions

Hydrophis platurus xanthos is a well-defined evolutionary subspecies inhabiting a small area of unusual geography. Given unique aspects of its behavioral ecology, it could well represent an intrinsically genetically isolated taxon of recent origin, in which case a species designation would be appropriate. We have been appropriately conservative here, in defining it at a subspecific level. This provides footing for protective strategies, while allowing future research to refine its taxonomic rank.

 Brooke L. Bessesen and Gary J. Galbreath. 2017. A New Subspecies of Sea Snake, Hydrophis platurus xanthos, from Golfo Dulce, Costa Rica.
 ZooKeys. 686: 109-123.  DOI:  10.3897/zookeys.686.12682

  

[Herpetology • 2006] Laticauda frontalis (de Vis, 1905) and Laticauda saintgironsi n. sp. from Vanuatu and New Caledonia (Serpentes: Elapidae: Laticaudinae) — A New Lineage of Sea Kraits?

Laticauda saintgironsi 

Cogger & Heatwole, 2006

 photo: twitter.com/bungarus666 

ABSTRACT 

The sea krait Laticauda colubrina is the most widespread member of its genus, extending from the Bay of Bengal through much of Asia and the Indo-Malayan Archipelago to New Guinea and many islands of the western Pacific Ocean. Unconfirmed records of the species may extend the range to the western coast of Central America. The species is subject to marked geographic variation in a number of morphological and meristic characters that have to date defied finer taxonomic resolution. Two members of this complex previously subsumed under the specific name colubrina are here formally elevated to full species status. One species — Laticauda saintgironsi n.sp. — consists of those populations of L. colubrina s.l. found around the coast and in the coastal waters of the main island of New Caledonia. The second species — Laticauda frontalis (de Vis, 1905) — is a dwarf species found in sympatry and syntopy with Laticauda colubrina in Vanuatu and the Loyalty Islands of New Caledonia.

  

 Harold G. Cogger and Harold F. Heatwole. 2006. Laticauda frontalis (de Vis, 1905) and Laticauda saintgironsi n.sp. from Vanuatu and New Caledonia (Serpentes: Elapidae: Laticaudinae) — A New Lineage of Sea Kraits?

Records of the Australian Museum. 58: 245–256.

http://researchonline.jcu.edu.au/3712/1/3712_Cogger_%26_Heatwole_2006.pdf

[Herpetology • 2016] The Evolution of Scale Sensilla in the Transition from Land to Sea in Elapid Snakes

Figure 2. High-depth-of-field photographs of the heads of six elapid species:
(a) Hydrophis schistosus, (b) Hydrophis platurus, (c) Aipysurus duboisii, (d) Emydocephalus annulatus, (e) Hydrelaps darwiniensis and (f) Pseudonaja textilis. Species are representative of (a–d) fully aquatic, (e) semi-aquatic and (f) terrestrial ecologies. Insets show sensilla within the postocular scale(s).

 Scale bar, 3 mm.  DOI: 10.1098/rsob.160054

Abstract

Scale sensilla are small tactile mechanosensory organs located on the head scales of many squamate reptiles (lizards and snakes). In sea snakes and sea kraits (Elapidae: Hydrophiinae), these scale organs are presumptive scale sensilla that purportedly function as both tactile mechanoreceptors and potentially as hydrodynamic receptors capable of sensing the displacement of water. We combined scanning electron microscopy, silicone casting of the skin and quadrate sampling with a phylogenetic analysis to assess morphological variation in sensilla on the postocular head scale(s) across four terrestrial, 13 fully aquatic and two semi-aquatic species of elapids. Substantial variation exists in the overall coverage of sensilla (0.8–6.5%) among the species sampled and is broadly overlapping in aquatic and terrestrial lineages. However, two observations suggest a divergent, possibly hydrodynamic sensory role of sensilla in sea snake and sea krait species. First, scale sensilla are more protruding (dome-shaped) in aquatic species than in their terrestrial counterparts. Second, exceptionally high overall coverage of sensilla is found only in the fully aquatic sea snakes, and this attribute appears to have evolved multiple times within this group. Our quantification of coverage as a proxy for relative ‘sensitivity’ represents the first analysis of the evolution of sensilla in the transition from terrestrial to marine habitats. However, evidence from physiological and behavioural studies is needed to confirm the functional role of scale sensilla in sea snakes and sea kraits.

KEYWORDS: sea snake; sensilla; mechanoreceptor; hydrodynamic; sensory; elapid

..............

 Conclusion:

Our study devised a novel approach to quantify the traits of scale sensilla, which enabled meaningful comparison across a broad sample of elapid snakes. In particular, our estimates of overall coverage of sensilla provided a proxy for putative mechanoreceptor sensitivity and allowed the first analysis of sensilla evolution in the transition from terrestrial to marine habits in snakes. Our results indicate multiple increases in overall coverage of sensilla within the fully aquatic sea snakes, in addition to a more dome-shaped sensillum ultrastructure in fully aquatic and semi-aquatic lineages compared with terrestrial lineages. These findings are consistent with a derived, possibly hydrodynamic, sensory role for scale sensilla in sea snakes and sea kraits, but rigorous testing of this hypothesis will ultimately require behavioural and physiological studies. The novel methodological approach presented here is easily transferable to other reptilian lineages that have undergone adaptive shifts.

Jenna M. Crowe-Riddell, Edward P. Snelling, Amy P. Watson, Anton Kyuseop Suh, Julian C. Partridge and Kate L. Sanders. 2016. The Evolution of Scale Sensilla in the Transition from Land to Sea in Elapid Snakes. [Royal Society] Open Biology. DOI: 10.1098/rsob.160054

Sea snakes can sense objects at a distance by feeling movements in the water
http://phy.so/384584007 via @physorg_com

[Herpetology • 2015] Molecules and Morphology Reveal Overlooked Populations of Two Presumed Extinct Australian Sea Snakes; Aipysurus foliosquama & A. apraefrontalis

Fig 2. Photographs of A,C: Aipysurus apraefrontalis (SAMA R68142) from Ashmore Reef;
and B, D: A. foliosquama (WAM R150365) from Barrow Island. 

doi:10.1371/journal.pone.0115679.g002

Abstract

The critically endangered leaf-scaled (Aipysurus foliosquama) and short-nosed (A. apraefrontalis) sea snakes are currently recognised only from Ashmore and Hibernia reefs ~600km off the northwest Australian coast. Steep population declines in both species were documented over 15 years and neither has been sighted on dedicated surveys of Ashmore and Hibernia since 2001. We examine specimens of these species that were collected from coastal northwest Australian habitats up until 2010 (A. foliosquama) and 2012 (A. apraefrontalis) and were either overlooked or treated as vagrants in conservation assessments. Morphological variation and mitochondrial sequence data confirm the assignment of these coastal specimens to A. foliosquama (Barrow Island, and offshore from Port Hedland) and A. apraefrontalis (Exmouth Gulf, and offshore from Roebourne and Broome). Collection dates, and molecular and morphological variation between coastal and offshore specimens, suggest that the coastal specimens are not vagrants as previously suspected, but instead represent separate breeding populations. The newly recognised populations present another chance for leaf-scaled and short-nosed sea snakes, but coastal habitats in northwest Australia are widely threatened by infrastructure developments and sea snakes are presently omitted from environmental impact assessments for industry. Further studies are urgently needed to assess these species’ remaining distributions, population structure, and extent of occurrence in protected areas.

Kate L. Sanders, Tina Schroeder, Michael L. Guinea and Arne R. Rasmussen. 2015. Molecules and Morphology Reveal Overlooked Populations of Two Presumed Extinct Australian Sea Snakes (Aipysurus: Hydrophiinae). PLoS ONE. 10(2) DOI: 10.1371/journal.pone.0115679

[Herpetology • 2014] Sea Snakes in Australian Waters (Serpentes: subfamilies Hydrophiinae and Laticaudinae) — A Review with an Updated Identification Key

some Australian Sea snakes 

DOI: 10.11646/zootaxa.3869.4.1

Abstract

Sea snakes (Elapidae, subfamilies Hydrophiinae and Laticaudinae) reach high species richness in the South China Sea and in the Australian region; however, most countries in the two regions still lack up-to-date checklists and identification tools for these snakes. We present an updated reviewed checklist and a new complete identification key to sea snakes in Australian waters. The identification key includes 29 species documented and 4 possibly occurring taxa and is based mostly on easy-to-use external characters. We find no evidence for breeding populations of Laticauda in Australian waters, but include the genus on the list of possibly occurring taxa.

Keywords: biodiversity, Australian sea snake species, identification key

Checklist of Sea Snake Species Known to Occur in Australia

Aipysurus apraefrontalis Smith, 1926
Aipysurus duboisii Bavay, 1869
Aipysurus foliosquama Smith, 1926
Aipysurus fuscus (Tschudi, 1837)
Aipysurus laevis Lacépède, 1804
Aipysurus mosaicus Sanders et al. 2012
Aipysurus pooleorum Smith, 1974
Aipysurus tenuis Lønnberg and Anderson, 1913
Emydocephalus annulatus Krefft, 1869
Ephalophis greyae Smith, 1931
Hydrelaps darwiniensis Boulenger, 1896
Hydrophis atriceps Günther, 1864
Hydrophis belcheri (Gray, 1849)
Hydrophis caerulescens (Shaw, 1802)
Hydrophis coggeri (Kharin, 1984a)
Hydrophis curtus (Shaw, 1802)
Hydrophis czeblukovi (Kharin, 1984a)
Hydrophis donaldi Ukuwela, Sanders and Fry 2012
Hydrophis elegans (Gray, 1842)
Hydrophis kingii Boulenger, 1896
Hydrophis macdowelli Kharin, 1983
Hydrophis major (Shaw, 1802)
Hydrophis ocellatus Gray, 1849
Hydrophis pacificus Boulenger, 1896
Hydrophis peronii (Duméril, 1853)
Hydrophis platurus (Linnaeus, 1766)
Hydrophis stokesii (Gray in Stokes, 1846)
Hydrophis zweifeli (Kharin, 1985)
Parahydrophis mertoni (Roux, 1910)

List of Sea Snakes Possibly Occurring in Australia
Hydrophis laboutei Rasmussen and Ineich, 2000
Hydrophis vorisi Kharin, 1984b
Microcephalophis gracilis (Shaw, 1802)
Laticauda sp. Laurenti, 1768

Arne Redsted Rasmussen, Kate Laura Sanders, Michael L. Guinea and Andrew P. Amey. 2014. Sea Snakes in Australian Waters (Serpentes: subfamilies Hydrophiinae and Laticaudinae) — A Review with an Updated Identification Key. Zootaxa. 3869 (4): 351–371 

http://dx.doi.org/10.11646/zootaxa.3869.4.1

http://mapress.com/zootaxa/2014/f/zt03869p371.pdf

[Herpetology • 2011] The Dangerously Venomous Snakes of the Philippine Archipelago with Identification Keys and Species Accounts

 Alan E. Leviton, Rafe M. Brown and Cameron D. Siler. 2011. The Dangerously Venomous Snakes of the Philippine Archipelago with Identification Keys and Species Accounts. In: Gary C. Williams and Terrence M. Gosliner [eds.] The Coral Triangle: The 2011 Hearst Biodiversity Philippine Expedition, Publisher: California Academy of Sciences. 473-530. 

researchgate.net/publication/263375284_The_dangerously_venomous_snakes_of_the_Philippine_Archipelago_with_identification_keys_and_species_accounts

[Herpetology • 2013] Recent rapid speciation and ecomorph divergence in Indo-Australian sea snakes | Shrunken Heads of Sea Snakes

Given their feeding habits, some sea snakes have developed 'shrunken heads'. An international team of scientists says this can lead to speciation (one species splitting into two). In the picture: small-headed snake foraging in waters off the Ryuku Islands, Japan.

Image: Yoshitaka Tahara

Abstract

The viviparous sea snakes (Hydrophiinae) are a young radiation of at least 62 species that display spectacular morphological diversity and high levels of local sympatry. To shed light on the mechanisms underlying sea snake diversification, we investigated recent speciation and eco-morphological differentiation in a clade of four nominal species with overlapping ranges in Southeast Asia and Australia. Analyses of morphology and stomach contents identified the presence of two distinct ecomorphs: a ‘macrocephalic’ ecomorph that reaches >2 m in length, has a large head and feeds on crevice-dwelling eels and gobies; and a ‘microcephalic’ ecomorph that rarely exceeds 1 m in length, has a small head and narrow fore-body and hunts snake eels in burrows. Mitochondrial sequences show a lack of reciprocal monophyly between ecomorphs and among putative species. However, individual assignment based on newly developed microsatellites separated co-distributed specimens into four significantly differentiated clusters corresponding to morphological species designations, indicating limited recent gene flow and progress towards speciation. A coalescent species tree (based on mitochondrial and nuclear sequences) and isolation-migration model (mitochondrial and microsatellite markers) suggest between one and three transitions between ecomorphs within the last approximately 1.2 million to approximately 840 000 years. In particular, the macrocephalic ‘eastern’ population of Hydrophis cyanocinctus and microcephalic H. melanocephalus appear to have diverged very recently and rapidly, resulting in major phenotypic differences and restriction of gene flow in sympatry. These results highlight the viviparous sea snakes as a promising system for speciation studies in the marine environment.

Keywords: Australia; ecomorph evolution; Hydrophis; marine speciation; sea snake; Southeast Asia

_____________________

Shrunken Heads of Sea Snakes Explained

http://www.livescience.com/28094-sea-snakes-shrunken-heads.html

Some sea snakes have heads that look comically small compared with the rest of their body. New research shows these shrunken heads evolved quite rapidly, allowing the snakes to hunt eels hiding in tight spaces.

If you only looked at the genes of the blue-banded sea snake and the slender-necked sea snake, the two species would seem nearly identical. But the close cousins, which are found in waters around Southeast Asia and Australia, have quite different physical looks, researchers say.

"The slender-necked sea snake is half the size, and has a much smaller head, than the blue-banded sea snake," study researcher Mike Lee, from the South Australian Museum, said in a statement. "This suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances."

The researchers believe some sea snakes developed shrunken heads to be more effective eaters since these species poke their heads into narrow eel burrows to look for food, whereas their big-headed cousins feast on crevice-sheltering eels and gobies.

"One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows — and subsequently stopped interbreeding with the large-headed forms," Lee added.

Both the blue-banded sea snake and the slender-necked sea snake belong to the genus Hydrophis. With more than 30 species, this group is by far the most diverse group in the Hydrophiinae subfamily and it has a lot of tiny-headed members. In fact, microcephaly (the condition of having a small head) has evolved at least eight separate times in Hydrophis during their relatively rapid diversification over the past 3.5 million years, researchers say.

Meanwhile, no other genus in the sea snake family (not Aipysurus nor Ephalophis nor Hydrelaps) has snakes that have evolved shrunken heads. What's more, these groups tend to be much less diverse, each represented by a half-dozen species at best.

"Rapid evolution of head size variation is therefore a likely contributing factor in the explosive speciation in Hydrophis group sea snakes," the researchers wrote in an article published this week in the journal Molecular Ecology.

Kate L. Sanders, Arne R. Rasmussen, Mumpuni, Johan Elmberg, Anslem de Silva, Michael L. Guinea, Michael S. Y. Lee. 2013. Recent rapid speciation and ecomorph divergence in Indo-Australian sea snakes. Molecular Ecology, | DOI: 10.1111/mec.12291/

http://squamates.blogspot.com/2013/03/evolution-of-microcephalic-sea-snakes.html

http://www.sciencealert.com.au/news/20131903-24171.html

http://www.wired.co.uk/news/archive/2013-03/20/small-headed-sea-snakes

[Herpetology • 2012] Molecular evidence that the deadliest sea snake Enhydrina schistosa (Elapidae: Hydrophiinae) consists of two convergent species

The deadliest sea snake is actually two look-alike species 

Sea snakes have some of the most potent venoms of any snake, but most of the 60 or so species are docile, rare, or sparing with their venom. The beaked sea snake (Enhydrina schistosa) is an exception. It lives throughout Asia and Australasia, has a reputation for being aggressive, and swims in estuaries and lagoons where it often gets entangled in fishing nets. Unwary fishermen get injected with venom that’s more potent than a cobra’s or a rattlesnake’s. It’s perhaps unsurprising that this one species accounts for the vast majority of injuries and deaths from sea snake bites.

>>> http://blogs.discovermagazine.com/notrocketscience/

..............

Abstract

We present a striking case of phenotypic convergence within the speciose and taxonomically unstable Hydrophis group of viviparous sea snakes. Enhydrina schistosa, the ‘beaked sea snake’, is abundant in coastal and inshore habitats throughout the Asian and Australian regions, where it is responsible for the large majority of recorded deaths and injuries from sea snake bites. Analyses of five independent mitochondrial and nuclear loci for populations spanning Australia, Indonesia and Sri Lanka indicate that this ‘species’ actually consists of two distinct lineages in Asia and Australia that are not closest relatives. As a result, Australian “E. schistosa” are elevated to species status and provisionally referred to Enhydrina zweifeli. Convergence in the characteristic ‘beaked’ morphology of these species is probably associated with the wide gape required to accommodate their spiny prey. Our findings have important implications for snake bite management in light of the medical importance of beaked sea snakes and the fact that the only sea snake anti-venom available is raised against Malaysian E. schistosa.

Highlights ► We present a striking case of phenotypic convergence within viviparous sea snakes. ► Enhydrina schistosa is distributed throughout the Asian and Australian seas. ► We analysed five independent mitochondrial and nuclear loci. ► Enhydrina schistosa consists of two independent lineages in Australia and Asia.

Keywords: Convergent evolution; Molecular phylogenetics; Cryptic species; Sea snakes; Venom

Ukuwela, de Silva, Mumpuni, Fry, Lee & Sanders. 2012. Molecular evidence that the deadliest sea snake Enhydrina schistosa (Elapidae: Hydrophiinae) consists of two convergent species. Molecular Phylogenetics and Evolution. http://dx.doi.org/10.1016/j.ympev.2012.09.031

The deadliest sea snake is actually two look-alike species http://blogs.discovermagazine.com/notrocketscience/2012/11/20/the-deadliest-sea-snake-is-actually-two-look-alike-species/

[Herpetology • 2011] Myron karnsi & M. resetari • Two new dwarf homalopsid snakes (Homalopsidae) from eastern Indonesia and western Australia

Two new dwarf homalopsid snakes of the genus Myron described in 2011. A. Myron karnsi from the Aru Islands in eastern Indonesia. B. Myron resetari from Western Australia. Both species have been long confused with Myron richardsonii, a species from northern Australia.These are small (less than 400 mm), coastal species that probably hunt fish in marine environments. They are two of a small number of snakes, other than true sea snakes and file snakes, that have been able to adapt to saltwater. M. karnsi is known from a single specimen, M. resetari was known from two specimens when described, but other specimens have been found in the last few months. JCM

Abstract

 The external morphology and systematics of Australasian homalopsid snakes are examined against the background of recent molecular work. Two new species (Myron karnsi and Myron resetari) in the genus Myron Gray 1849 are described using the external morphology commonly applied to snake species. Cantoria annulata Jong 1926 and Hypsirhina polylepis Fisher 1886 represent endemic Australasian genera; Cantoria annulata is assigned a new genus, and the genus Pseudoferania Ogilby 1891 is resurrected for Enhydris polylepis. The zoogeography of the Australasian homalopsid clade is discussed.

Key words:– homalopsids, Myron, Cantoria, Enhydris,  Heurnia, nomenclature, new genus, new species.

Myron karnsi, new species

Holotype: SMF 19569. 

Type Locality: Indonesia Aru, Kobroor, Selrutti (about 5º46'S and 134º31'E).

1917 Myron richardsoni — Rooij, 2:192

Etymology. – This species is named in honour of Daryl R. Karns, Hanover College and the Division of Amphibians and Reptiles, Field Museum of Natural History for his contributions to herpetological research and work with homalopsid snakes.

Distribution. – Known only from the type locality.

Myron resetari, new species

Holotype: QM J52861. 

Type locality: Broome, Western Australia (about 17º58'S and 122º14'E).

1970 Myron richardsonii — Gyi, pages 172–174, Fig. 28.

Etymology. – The specifi c name is in honour of Alan Resetar of the Division of Amphibians and Reptiles, Field Museum of Natural History for his life long dedication to herpetology and his behind the scenes contributions to homalopsid snake research.

Distribution. – Known only from the type locality, Broome, Western Australia; but it may be more widespread. Given Myron’s use of mangroves and mudfl ats it seems likely this snake is from the Roebuck Bay area of the Dampier Peninsula.

Murphy, John C. 2011. The nomenclature and systematics of some Australasian Homalopsid snakes (Squamata: Serpentes: Homalopsidae). The Raffles Bulletin of Zoology, 59(2):229-236.

http://rmbr.nus.edu.sg/rbz/biblio/592/59rbz229-236.pdf

http://squamates.blogspot.com/2011/12/old-new-species.html

http://www.arod.com.au/arod/reptilia/Squamata/Colubridae/Myron

[Herpetology • 2012] Hydrophis donaldi | Rough-scaled Sea Snake • a highly distinctive new species of sea snake (Elapidae, Hydrophiinae) from Gulf of Carpentaria, northern Australia

Rough-scaled Sea Snake | Hydrophis donaldi Ukuwela, Sanders & Fry, 2012

Abstract

A new species of viviparous sea snake, Hydrophis donaldi sp. nov. (Hydrophiinae), is described from the Gulf of Carpentaria, northern Australia. Molecular analyses reveal this species as a deeply divergent lineage within the Hydrophis subgroup, and separate it from all other sampled taxa by fixed nucleotide substitutions at three independent mitochondrial and nuclear loci. The new species is assigned to Hydrophis based on the current morphological diagnosis of this large but paraphyletic genus, and is distinguished from all other Hydrophis species and closely allied genera by a combination of morphological characters relating to scalation, colour pattern and osteology. Using current keys for sea snakes, H. donaldi sp. nov. might be mistaken for H. coggeri, H. sibauensis or H. torquatus diadema but it is readily distinguished from these 

species by a higher number of bands on the body and tail, lower ventral count, strongly spinous body scales, and a wider, more rounded head. Sea snakes have been sampled intensively in the Gulf of Carpentaria due to their vulnerability to bycatch in the region’s commercial prawn-trawl fisheries. That this highly distinctive new species has evaded discovery in the region until now is surprising, but might be explained by its habitat preferences. All known specimens of H. donaldi sp. nov. were found in estuarine habitats that are relatively poorly surveyed and are not targeted by commercial fisheries. 

Key words: Estuary, Gulf of Carpentaria, Hydrophis, phylogenetics, taxonomy

Bryan Fry (the third author) with Hydrophis donaldi

Top: Bryan Fry (the third author) with Hydrophis donaldi

Bottom: Olive sea snake, Aipysurus laevis

‘rough-scaled sea snake’ : http://www.sci-news.com/biology/article00191.html

http://www.uq.edu.au/news/index.html?article=24428

Spiny, Venomous New Sea Snake Discovered — http://on.natgeo.com/A7u5WL 

Hydrophis donaldi (Elapidae, Hydrophiinae), a highly distinctive new species of sea snake from northern Australia: http://mapress.com/zootaxa/2012/f/z03201p057f.pdf

[Herpetology • 2011] Sea snakes in Vietnam (Serpentes: subfamilies Hydrophiinae and Laticaudinae): a comprehensive checklist and an updated identification key

Sea snakes from Vietnam: Acalyptophis peronii, Kerilia jerdonii, Thalassophina viperina, Hydrophis atriceps, H. belcheri, H. cyanocinctus, H. lamberti, H. melanocephalus, H. ornatus & H. pachycercos

Abstract

Sea snakes (Elapidae, subfamilies Hydrophiinae and Laticaudinae) reach a very high species richness in Southeast Asia, but most countries in the region still lack comprehensive and up-to-date identification tools for these snakes. We presentan updated checklist of sea snakes in Vietnam. We also provide diagnostic characters for all species and a new complete identification key, chiefly based on easy-to-use external characters. The checklist and key cover the 25 species documented from Vietnam, as well as three likely future additions to its sea snake fauna. By surveying incoming fishing vessels between Nha Trang and the mouth of Mekong River in 2000–2001, we were able to document two species new for Vietnamese waters: Hydrophis belcheri and H. pachycercos. Through these surveys we also secured four specimens of the rare endemic species H. parviceps, formerly known only from two specimens. A comprehensive bibliography of the literature treating sea snakes in Vietnamese waters is provided.

Identification key: bibliography, biodiversity, diagnostic characters, Vietnamese waters

Rasmussen, A. R.; Elmberg, J., Gravlund, P. and Ineich, I. 2011. Sea snakes (Serpentes: subfamilies Hydrophiinae and Laticaudinae) in Vietnam: a comprehensive checklist and an updated identification key. Zootaxa 2894: 1–20

http://www.mapress.com/zootaxa/2011/f/zt02894p020.pdf