Roundbelly Cowfish

Roundbelly Cowfish (Lactoria diaphana)

The Roundbelly Cowfish (Lactoria diaphana) is a small, tropical marine species known for its distinct boxy shape and vibrant colors. Its body is encased in a hard, bony carapace, which provides protection from predators, and it has a rounded belly that gives it its name. Unlike many fish, the roundbelly cowfish swims using a unique undulating motion of its dorsal and anal fins, which gives it a graceful, almost hovering movement in the water.

Primarily found in the Indo-Pacific region, roundbelly cowfish inhabit coral reefs and lagoons, where they feed on small invertebrates, including sponges, mollusks, and crustaceans. They use their small, beak-like mouths to pick food off the seafloor. Their diet contributes to the health of the reef ecosystem by controlling invertebrate populations.

One of the most intriguing aspects of the roundbelly cowfish is its ability to release a toxic substance, ostracitoxin, when stressed or threatened. This defense mechanism can be harmful to nearby marine life, making the cowfish a species that needs careful handling in captivity. Despite its defensive toxins, it is a popular choice for large saltwater aquariums due to its striking appearance and quirky swimming behavior.