Humpback Turretfish

(Tetrosomus gibbosus)
Tetrosomus gibbosus, commonly known as the Humpback turretfish or the Helmet cowfish, is a species of boxfish belonging to the family Ostraciidae. Here are some key characteristics and information about Tetrosomus gibbosus:
  1. Physical Appearance: The Humpback turretfish has a boxy, angular body covered with rigid, hexagonal plates fused together to form a protective carapace. It has a prominent hump or ridge along its back, giving it a distinctive appearance. The coloration is typically yellowish to orange with dark spots or mottling, although it can vary depending on its environment and mood. The fins are small and paddle-like, aiding in its slow and deliberate movement.
  2. Size: They typically grow to a maximum length of about 15-20 centimeters (6-8 inches), although sizes can vary.
  3. Distribution: Tetrosomus gibbosus is found in the tropical and subtropical waters of the Indo-Pacific region. Its range includes the Red Sea and the eastern coast of Africa to the western Pacific Ocean, including regions such as Indonesia, Philippines, Australia, and the islands of the western Indian Ocean.
  4. Habitat: Humpback turretfish inhabit coral reefs, rocky areas, and seagrass beds with rich coral growth. They are often found in shallow to moderate depths, typically up to 30 meters (100 feet) deep. They prefer areas with ample hiding places among coral heads, rocks, and crevices, where they can retreat when threatened.
  5. Behavior: These boxfish are slow-moving and peaceful, grazing on algae, small invertebrates, and occasionally small crustaceans. They are not aggressive towards other fish but can be territorial towards conspecifics or similar-shaped species.
  6. Defense Mechanism: Like other boxfish, Tetrosomus gibbosus has a remarkable defense mechanism where it secretes a potent toxin, known as pahutoxin, from its skin when stressed or threatened. This toxin acts as a deterrent against predators and can be harmful to other fish and organisms in close proximity.