Lactoria fornasini (Bianconi, 1846)

Nomenclature

This species, commonly known as the thornback cowfish, has the scientific name Lactoria fornasini (Bianconi, 1846).

Carapace Structure

Like other members of the Ostraciidae family, the thornback cowfish has hexagonal, plate-like scales that are fused together to create a solid, box-shaped carapace. The fish’s eyes, mouth, fins, and tail all protrude from this carapace.

Body Shape

Its mouth is small with protruding lips, the upper profile of its snout is straight, its back is somewhat convex, its flanks are concave, and its belly is rounded, giving the fish a shape that resembles a purse.

Spine Morphology

Small pre-ocular spines grow on either side of its head, a large spine projects from its dorsal ridge, and an additional moderate-sized spine grows from each of its pelvic ridges near the anal fin.

Fin Structure

Neither the dorsal fin nor the anal fin has spines, and both fins have nine soft rays, while the fan-shaped caudal fin has ten rays.

Size

A typical individual of this species reaches about 15 cm (6 in) in length.

Coloration

Its colouring is variable and changes to camouflage with its surroundings; it is generally pale tan, with spots or wiggly markings in yellow, mauve or blue.

Toxicity

In some regions, this fish is toxic.

Distribution Range

The thornback cowfish is native to the tropical Indo-Pacific region, located between 32°N and 32°S. Its range stretches from the east coast of Africa between Tanzania and South Africa, and the island of Madagascar, eastward to Japan, Indonesia, Australia, Hawaii, and Rapa Island.

Habitat

It inhabits areas with sand, rubble, corals, and algae, found in both lagoons and on the seaward side of reefs.

Depth Range

It can occur at depths as great as 132 m (433 ft), but its most common depth range is between approximately 6 and 30 m (20 and 100 ft).

Social Behavior

Thornback cowfish are usually solitary, but males become territorial during the breeding season.

Diet

Their diet is made up of small invertebrates.

Feeding Behavior

The fish blows jets of water from its mouth to displace sand and expose prey, then sucks prey up from the sea bed.

Population Status

This is an uncommon species.

Defense Mechanism

Like other boxfishes, the thornback cowfish can release a soap-like toxin called pahutoxin through its skin when it is stressed. This toxin can incapacitate or even kill potential predators.