Epaulette Shark

The epaulette shark has an elongated body, over half of which is comprised by the slender caudal peduncle. The snout is short and rounded, with the nares placed almost at the tip along with a pair of tiny barbels; there are grooves running from the nares to the mouth. There are 26–35 tooth rows in the upper jaw and 21–32 tooth rows in the lower jaw. The teeth are small, with broad bases and triangular cusps. The eyes are oval in shape and elevated, with a large spiracle below each. The five pairs of gill slits are small, with the fourth and fifth very close together.

The range of the epaulette shark extends from the southern coast of New Guinea to the northern coast of Australia, as far south as Sydney. The Capricorn-Bunker Group of the Great Barrier Reef contains a particularly large population, with thousands estimated to inhabit the reefs around Heron Island alone. The estimated population density of these reefs is approximately 0.3 to 1.2 individuals per 100 square meters. Additionally, there are unsubstantiated reports of this species from Malaysia, Sumatra, and the Solomon Islands. Epaulette sharks are found in shallow water to a maximum depth of 50 m (160 ft), and are often seen in water barely deep enough to cover their bodies. They prefer tidal pools, coral flats, and stands of staghorn coral.

The epaulette shark is an opportunistic predator of benthic crustaceans, worms, and small bony fish. Off Heron Island, over 90% of the epaulette shark's diet consists of polychaete worms and crabs, with juveniles taking mostly the former and adults mostly the latter. It hunts most actively at dawn and dusk, though feeding can occur at any time during the day. This shark relies mainly on its olfactory and electroreceptive senses to locate hidden prey. It is capable of sucking prey into its mouth by expanding its muscular buccal cavity. While searching for food, the epaulette shark sometimes turns over debris with its snout or thrusts its head into the sand, swallowing food items while expelling the sand grains through its gill slits. Unlike most sharks, the epaulette shark may chew its food for up to 5–10 minutes.

As an adaptation for navigating its complex reef environment, the epaulette shark moves by seemingly walking, bending its body from side-to-side and pushing off of the substrate with its paddle-shaped pectoral and pelvic fins. Its gait is similar to that of salamanders, an example of convergent evolution. The shark is capable of swimming, but often prefers to walk along the sandy or coral bottom even when the water is deep enough to allow it to swim freely. The cartilaginous supports of the epaulette shark's paired fins are reduced and separated when compared to other sharks, allowing them to be rotated for use as limbs. This mode of locomotion even enables the shark to crawl out of the water to access isolated tidal pools.

Epaulette sharks are harmless to humans, though if handled they may nip their captors. They are easily observed and handled by beachgoers as they move slowly whilst out of water, and show little fear of humans. This species adapts readily to captivity and is displayed by many public aquariums in the United States, Canada, and Australia. In an article for Aquarium Fish Magazine, Scott W. Michael referred to the epaulette shark as "the best shark for the home aquarium." They will breed in captivity, even in tanks as small as 510 L (135 gal), though full-grown sharks are best housed in tanks of 680 L (180 gal) or more. They are not compatible with community tanks as they will eat other fish.