How to Identify a Sea Krait (Identification Guide)

Key identifying features

Sea kraits are semi-aquatic elapids adapted to both marine and terrestrial environments, distinguished by a laterally flattened, paddle-shaped tail used for swimming, combined with a body otherwise similar to terrestrial kraits. The body is cylindrical for most of its length, only flattening near the tail.

Coloration & pattern

Most sea kraits show bold black and pale bluish-gray, white, or pale blue banding, with rings typically encircling the body completely. The pattern usually remains crisp and high-contrast, aiding visibility in the species' shallow reef and coastal habitats. The head is often solid black or dark, contrasting sharply with pale bands on the neck.

Head, eyes & scales

The head is small and only slightly wider than the neck, colored dark or black in most species. Nostrils are positioned on top of the snout, an adaptation for breathing at the surface. Scales are smooth and glossy, and the body scales are notably tough, providing protection against abrasive coral and rock surfaces.

Size & body shape

Sea kraits typically reach 1 to 1.5 meters in length, with a moderately slender body that is round in cross-section along most of its length but becomes laterally compressed and paddle-like at the tail, a clear adaptation for swimming.

Range & habitat where you'll see it

Sea kraits are found throughout the Indo-Pacific, inhabiting coral reefs, rocky coastlines, and adjacent land areas, since they return to land to digest food, rest, and lay eggs, unlike fully marine sea snakes. They are often seen both in shallow water and basking or resting on rocks or beaches.

How to tell it apart from look-alikes

The combination of bold black-and-pale banding, a paddle-shaped tail, and top-positioned nostrils separates sea kraits from fully aquatic sea snakes, which typically have reduced ventral scales unsuited for movement on land and cannot leave the water. Terrestrial kraits lack the flattened, paddle-like tail seen in sea kraits.