The zebra bullhead shark, Heterodontus zebra, is a bottom-dwelling shark known for its distinctive appearance. This unique fish, part of the bullhead shark family.
Defining Features
The zebra bullhead shark possesses a robust body and a large, blunt head that gives it its “bullhead” designation. Low ridges above its eyes gradually slope backward. Its most striking feature is the pattern of about 12 narrow, dark brown or black vertical bands against a lighter tan or whitish background, extending from its snout to its tail.
This shark typically reaches an average length of 80 to 100 cm (approximately 2.6 to 3.3 feet), though some individuals can grow up to 122 cm (about 4 feet). It has two tall dorsal fins, each equipped with a stout, sharp spine at its leading edge. These physical attributes classify it within the Heterodontidae family, a group of sharks known for their unique head shapes and banded patterns.
Natural Habitat and Daily Life
The zebra bullhead shark inhabits the tropical and subtropical waters of the Western Pacific, ranging from Japan and Korea southward to Australia, including areas like China, Vietnam, and Indonesia. It typically resides on the continental and insular shelves at depths down to at least 50 meters (160 feet). Off Western Australia, it can be found in deeper waters, between 150 and 200 meters (490 to 660 feet).
This shark prefers environments with rocky reefs, kelp forests, and sandy or muddy bottoms, often seeking shelter in caves and under ledges during the day. It is a nocturnal species, emerging at night to forage along the seafloor, using its pectoral and pelvic fins to “walk” across the bottom. While solitary, they may form small aggregations, particularly during breeding seasons.
Feeding and Reproduction
The zebra bullhead shark is a carnivore that primarily feeds on bottom-dwelling invertebrates. Its diet includes crustaceans, mollusks, and sea urchins, along with small bony fishes. Its specialized teeth, including flat, molar-like hind teeth, crush the hard shells of its prey. This species uses its snout to detect electrical signals from hidden prey on the seafloor.
Reproduction in the zebra bullhead shark is oviparous, meaning it lays eggs. Females lay two eggs at a time, typically between spring and late summer in regions like Japan. These eggs are encased in a corkscrew-shaped, leathery egg case, measuring about 12 to 18 cm (4.7 to 7 inches) long. The female wedges these egg cases into crevices among rocks or kelp, with embryos feeding solely on the yolk within the case. The eggs hatch after approximately one year, releasing hatchlings around 18 cm (7 inches) in length.
Conservation Status and Human Encounters
The zebra bullhead shark is currently classified as “Least Concern” by the IUCN Red List. While it is not a primary target for commercial fisheries, it can be caught as bycatch in trawling operations that target other species. Its preference for rocky habitats offers some natural protection from certain fishing methods.
This shark poses no threat to humans and is considered docile. Its appearance makes it a popular species for display in public aquariums worldwide. Conservation efforts are in place in some coastal areas of Asia to protect this species and its relatives.