HEMISCYLLIIDAE LONGTAIL CARPETSHARKS

The Hemiscylliidae are a family of sharks belonging the order Orectolobiformes, commonly known as the Longtail carpetsharks and sometimes the Bamboo sharks. They are mainly found in shallow waters of the tropical Indo-Pacific and western Pacific. They can be found in intertidal pools, very shallow water, rocky and coral reefs close inshore and on sediments. They are also found inshore and offshore in bays.

They are relatively small sharks, with the largest species reaching no more than 4 feet, but typically less than 3.3 feet long in adult body length. They have elongated, slender, cylindrical bodies. They have short barbels and large spiracles that are below the eyes. The mouth is small and transverse and is well in front of the dorsolateral eyes. They have nasoral and circumnarial grooves. As their common name suggests, they have unusually long tails, which exceed the length of the rest of their bodies. They have two spineless dorsal fins of equal size. The origin of the second dorsal fin is well ahead of the origin of the long, low rounded anal fin. The anal fin is separated by a notch from the lower caudal fin. The color pattern of young is often different and bolder than the color pattern of adults.

Their biology is poorly known. Some (but presumably all species) are oviparous. The egg cases are oval in shape. Research suggests that since there is a distinct and different color pattern in young than adults, that they have much different habitat preferences. They have strong, muscular leg-like paired fins that are more than likely used to climb on reefs and in and around crevices. They are sluggish fish, feeding on bottom-dwelling invertebrates and smaller fish, cephalopods, crustaceans, and shelled mollusks.

The British press on February 10, 2016 reported that a bamboo shark at Great Yarmouth’s Sea Life Centre was pregnant with two fertilized eggs. It is known that the shark has not come into contact with any other bamboo sharks since 2013. Although parthenogenesis is observed in a small number of species, this is such a rare occurrence in this species that it became a news story (Martin, Sean (2016-02-10) A miracle? Female bamboo shark set for VIRGIN BIRTH at British zoo. Express.co.uk. Retrieved on 2017-03-08.).

Hemiscylliidae are taken in multispecies fisheries and as bycatch, sometimes in large numbers. They are hardy and attractive and bred in captivity. They are often common to abundant, but some species are rare with limited distribution in threatened habitats. Hemiscylliid sharks can easily strive in captivity. They are sometimes kept in home aquaria. Species from this family are sought-out aquarium sharks because their natural habitats are tidepools, coral beds, and around boulders. This predisposition towards relatively confined spaces helps them adapt better to captivity compared to other species. One common mistake by aquarists is with decorating the aquarium itself. Unstable tank decor has been known to cause fatal injuries when the structure is disturbed by the sharks’ digging behavior. This is why home aquaria should not be encouraged.

There are 2 genera with a total of 17 species.

Chiloscyllium

They Are mainly found in the Indo-west Pacific. This genus is distinguished by a relatively long snout with subterminal nostrils. The eyes and supraorbital ridges are hardly elevated. The mouth is closer to the eyes than to the tip of the snout, with lower labial folds usually connected across the chin by a flap of skin. The pectoral and pelvic fins are thin and not very muscular. No black hood on the head or large black spot on the side of the body is present. Juveniles often are strongly marked with dark spots or bars.

Hemiscyllium

They are mainly found in the western Pacific. This genus is mostly confined to tropical waters off Australia, Papua New Guinea, and Indonesia, but an individual from this genus, possibly representing an undescribed species, has been photographed at the Seychelles. They have short snouts with the nostrils placed almost at the tip, and well-elevated eyes and obvious supraorbital ridges. The mouth is closer to the tip of the snout than the eyes and lacks the connecting dermal fold across the chin. The pectoral and pelvic fins are thick and heavily muscular. Either a black hood on the head or a large black spot on the sides of the body is present. The large epaulette spots may be mimicked eyespots used to intimidate predators.