Hawaii's Reef Fishes

Needlefishes (Belonidae)

Needlefishes are very elongate with long pointed jaws bearing numerous needle-like teeth; there are no spines in the fins; the dorsal and anal fins are posterior on the body; the lateral line passes along the lower side.

These fishes are surface-dwelling and protectively colored green or blue on the back and silvery below; some species have green bones. They feed mainly on small fishes.

When frightened, as by a predator or approaching boat, or confused by a light at night, they may leap and skitter at the surface. People have been injured by being struck by the larger needlefishes, and fatalities have been reported.

Four marine species occur in Hawaiian waters; the two presented below are the most common.

Houndfish

Tylosurus crocodilus (Peron & Lesueur, 1821) 'Aha

Green on the back, silvery below; a blackish keel on side of caudal pedunde; body slender in juveniles, progressively less elongate in adults; jaws relatively shorter with growth; anterior part of dorsal and anal fins elevated. The largest of the needlefishes; attains at least 53 inches (135 cm).

Worldwide in warm seas, usually in coastal waters.This living javelin is a hazard to those using a light at night.

Keeltail Needlefish

Platybelone argalus (Lesueur, 1821) 'Aha

Blue or blue-green dorsally, silvery on sides and ventrally; body and jaws extremely elongate ;body width slightly greater than depth, the caudal pedunde about twice as wide as deep, with a keel on the side. Attains nearly 18 inches (45 cm).

Divisible into 5 subspecies: Indo-Pacific, eastern Pacific, Arabian, and north and south Atlantic. Occurs inshore; often observed in small aggregations.

All information and pictures in this section are from John E. Randall's Shore Fishes of Hawai'i by permission of the author.