Aeoliscus strigatus (Günther, 1861)

Common and Scientific Name

This species, commonly called razorfish, has the scientific name Aeoliscus strigatus (Günther, 1861).

Distinct Identification Features

The razorfish is easy to identify by its unique body shape and its habit of moving in synchronized groups with its head pointing downward.

Size

It is a small fish that reaches a maximum length of 15 cm (5.9 in).

Body Shape

Its body is elongated and ends in a thin, long beak.

Fin Structure

Its fins are significantly reduced in size and transparent.

Body Armor

The dorsal surface of the razorfish is covered by protective bony plates; these plates extend past the end of the body and over the tail fin, which ends in a sharp spine.

Body Markings

A black to brown median stripe runs along the entire length of the fish, and crosses over its eyes.

Habitat-Dependent Coloration

The fish’s body color varies based on its habitat. In seagrass environments, the body’s base color may be greenish-yellow with light brown stripes. In open areas such as sand patches, rubble, or near coral reefs, the body color is light silver with a black to brown stripe.

Sexual Dimorphism

No sexual dimorphism has been documented in this species.

Diet

Ecologically, the razorfish feeds primarily on small brine shrimp and other small invertebrates, and it is also known to eat tiny crustaceans.

Sea Urchin Association

In the wild, razorfish have been observed hiding among the spines of sea urchins, using this behavior both for defense and for hunting. When threatened by larger fish, the razorfish darts to a nearby sea urchin or staghorn coral for protection.

Hunting Behavior

Razorfish hunt among sea urchin spines, particularly those of the genus Diadema, and wait for small invertebrates that feed on the urchins. When prey approaches, the razorfish darts out to attempt to catch it.

Reproduction

This species is oviparous; its eggs and larvae are pelagic.

Juvenile Habitat

Juveniles settle when they grow to 20 millimetres (0.79 in) in length, and most often choose to live among the spines of Diadema sea urchins.