Hydrophis major (Shaw, 1802)

Dorsal Coloration

Hydrophis major (Shaw, 1802) has a yellowish or pale brownish dorsal surface, marked with darker brown or blackish crossbars. These crossbars may be uniformly wide, or alternate between broad and narrow widths.

Ventral Coloration

Its ventral surface is white, and may or may not have small dark brown spots.

Size

Adult individuals can reach a total length of 105 cm (3 ft 5+3⁄8 in), with a tail that is 12 cm (4+3⁄4 in) long.

Dorsal Scale Structure

Dorsal scales are overlapping (imbricate), strongly keeled on the neck, and weakly keeled on the body. They are arranged in 31–36 rows around the neck, and 36–41 rows at midbody.

Ventral Scale Count

There are 200–236 ventrals.

Body and Head Shape

The head is moderate in size, and the body is stout.

Rostral Scale Morphology

The rostral scale is as broad as it is deep.

Nasal and Frontal Scales

Nasal scales are shorter than the frontal scale, and more than twice as long as the suture between the prefrontal scales. The frontal scale is longer than it is broad, and its length matches its distance from the tip of the snout.

Ocular and Temporal Scales

There is one preocular and two postoculars, with two superposed anterior temporals.

Upper Labial Scales

There are seven or eight upper labials, with the third and fourth labials entering the eye socket.

Chin Shields

There is only one pair of small chin shields.

Ventral Scale Morphology

Ventrals are distinguishable but very small, and may be either smooth or bicarinate.

Distribution

This species occurs in the eastern Indian Ocean and western central Pacific Ocean, in waters off southern New Guinea, New Caledonia, and Australia (specifically New South Wales, the Northern Territory, Queensland, and Western Australia).