The Cubicus Boxfish (Ostracion cubicum), also known as the Yellow Boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae. It is found in reefs throughout the Pacific and Indian Oceans.

Distribution and Habitat

The Cubicus Boxfish has a wide Indo-Pacific distribution from the Red Sea and the eastern coast of Africa to Hawaii, north to Japan and south to northern New Zealand. It is found at depths between 1 and 75 meters on sheltered coastal and offshore coral reefs.

Physical Description

The Cubicus Boxfish reaches a maximum length of 45 cm (18 in). As the name suggests, it is box-shaped with a rigid armored body called a carapace. When juvenile, it is bright yellow with black spots. As it ages, the brightness fades and very old specimens have blue-grey to black coloration with faded yellow.

Diet and Feeding

The Cubicus Boxfish feeds mainly on benthic organisms and marine algae including worms, sponges, crustaceans, molluscs, and small fish. In captivity it accepts a varied diet including mysis shrimp, brine shrimp, and frozen preparations.

Behavior and Reproduction

This species is generally peaceful but can release toxic mucus when stressed.

Aquarium Care

It requires a large tank of at least 100 gallons. It is not considered reef-safe as it may nip at corals and invertebrates.

Conservation Status

Classified as Least Concern by the IUCN Red List.