Epaulette Shark, Hemiscyllium ocellatum

The Epaulette Shark (Hemiscyllium ocellatum) is a species of longtailed carpet shark belonging to the family Hemiscylliidae, found in shallow and tropical waters off Australia and New Guinea. The common name of this shark comes from the very large and white-margined black spot behind each pectoral fin, which remind one of military epaulettes. As a small species, it usually measures under 3.3 feet long. The epaulette shark has a slender body with a short head and broad, paddle-shaped paired fins. The caudal peduncle comprises over half the length of the shark. The adults are light brown colored above, with scattered darker spots and indistinct saddles.

These sharks have nocturnal habits and frequent shallow water on coral reefs or in tidal pools. It has evolved to cope with the severe nighttime oxygen depletion in isolated tidal pools by increasing the blood supply to its brain and selectively shutting down unnecessary neural functions. It has the capability of surviving complete anoxia for an hour without ill effects, and at a much higher temperature than most other hypoxia-tolerant animals. This shark “walks” as opposed to swimming by wriggling their bodies and pushing with their paired fins. This species feeds on a wide range of small benthic invertebrates and bony fishes. The sharks are oviparous, with the females depositing pairs of egg capsules around every 14 days from August to December. Because of their hardiness and small size, epaulette sharks are popular with both home and public aquaria. The International Union for Conservation of Nature has assessed this species as of Least Concern, as outside of the small aquarium trade it is of little interest to the fisheries.

Image Caption: Hemiscyllium ocellatum. Credit: Citron/Wikipedia (CC BY-SA 3.0)