Fine-Spined Sea Snake

The fine-spined sea snake, more widely known as the spine-bellied sea snake, is a fully aquatic elapid found throughout warm coastal waters of the Indo-Pacific. It is one of the most frequently encountered sea snakes in trawl bycatch, which has made it a well-studied species for venom research and fisheries interaction data.

It belongs to the diverse Hydrophiinae group of marine elapids that evolved from Australian terrestrial ancestors. Like other sea snakes, it possesses a laterally compressed, paddle-like tail for swimming and carries a potent neurotoxic venom used to subdue prey.

• Stout, thick-bodied snake with a small head relative to body girth
• Coloration typically pale grey, olive, or yellowish with dark grey-brown crossbands or blotches along the back
• Bands often narrow toward the belly, giving an irregular saddle-like pattern
• Ventral scales bear a low keel or ridge, giving rise to the "fine-spined" common name
• Body scales are strongly overlapping and keeled, unlike the smooth scales of many other sea snakes
• Laterally compressed, oar-like tail used for propulsion
• Adults typically reach 0.7-1.0 m in length

Found in shallow coastal and estuarine waters, often over soft muddy or sandy bottoms near river mouths, mangroves, and continental shelf areas. Ranges from the Persian Gulf and Arabian Sea across South and Southeast Asia to northern Australia and parts of the western Pacific. Commonly encountered at depths of a few meters down to around 50 m, and is one of the sea snake species most regularly caught in shrimp trawl nets.

Primarily nocturnal, resting on the seabed or near the surface during the day. Feeds mainly on small fish, particularly gobies and other bottom-dwelling species, which it locates and captures using its venom. Reproduction is ovoviviparous, with females giving birth to live young in the water rather than laying eggs; litters typically number a handful of offspring.