How to Identify Jerdon's Sea Snake (Identification Guide)

Key identifying features

Jerdon's Sea Snake (Kerilia jerdonii) is a small marine species notable for its unusually short, deep head shape, distinct from the more elongated heads of many related sea snakes, an adaptation linked to its specialized burrowing prey capture.

Coloration & pattern

The body is generally pale gray, olive-gray, or brownish, marked with faint to moderate darker crossbands or blotches that may be more visible toward the rear of the body. The pattern tends to be subdued rather than boldly contrasting, and can be difficult to discern in murky water or on preserved specimens.

Head, eyes & scales

The head is short and relatively deep from top to bottom, appearing somewhat blunt compared to the narrower, more tapered heads of many other sea snakes. Eyes are small with round pupils. Body scales are smooth, contributing to the overall sleek marine snake profile.

Size & body shape

This is a small to medium sea snake, typically reaching 50 to 80 cm in length, with a moderately slender body that tapers to a flattened, paddle-like tail. The body proportions are fairly even from front to rear compared to some sea snakes with dramatic front-to-back size differences.

Range & habitat where you'll see it

Jerdon's Sea Snake occurs in coastal waters of South and Southeast Asia, including the Bay of Bengal and surrounding regions, typically in shallow, muddy, or sandy coastal habitats where it forages among burrows for small prey.

How to tell it apart from look-alikes

The short, deep head shape is the primary feature separating Jerdon's Sea Snake from more common Hydrophis species with elongated heads. Because body banding is often faint, head shape and overall small size are more reliable identification cues than pattern alone.