A near-threatened catshark sought by aquarists

The Coral catshark (Atelomycterus marmoratus) is a species of shark belonging to the family Scyliorhinidae. It is common on shallow coral reefs across the Indo-West Pacific, from Pakistan to New Guinea and southern China. The coral catshark has an extremely slender body, a short head and tail, and two dorsal fins that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form dashes and bars. It has a maximum recorded length of 2.3 feet.


Family: Scyliorhinidae – Catsharks

Genus: Atelomycterus 

Species: marmoratus


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Scyliorhinidae

Common NameCatsharks




Average Size and Length: The length of hatchlings is unknown but probably around 10 cm. Mature males measure between 47-62 cm/1.5-2 feet. Mature females measure between 49-57 cm/1.6-1.9 feet. The maximum recorded is 70 cm/2.3 feet.

Current Rare Mythical Sightings: The coral catshark was first described by an anonymous author, usually referred to English zoologist Edward Turner Bennett, in the 1830 Memoir of the Life and Public Services of Sir Thomas Stamford Raffles. Its original name was Scyllium marmoratum, from the Latin “marmoratus” meaning “marbled”. In 1913, Samuel Garman placed it in his newly created genus Atelomycterus. The type specimen was caught off Sumatra and is suspected to have been lost.

Teeth and Jaw: The mouth is extremely long and angular. There are very long labial furrows which extend onto both the upper and lower jaws. The small teeth have a narrow central cusp flanked by 1–2 cusplets on both sides.

Head: The head is narrow and short. The snout is short and slightly flattened, with a blunt tip. The eyes are horizontally oval and protected by rudimentary nictitating membranes. There are spiracles behind the eyes and are medium in size. There are greatly expanded anterior nasal flaps that extend to the mouth. There are nasoral grooves with small incurrent and excurrent openings.

Denticles: The dermal denticles are calcified and form a thick covering over the shark.

Tail: The caudal fin is relatively short and broad, with an indistinct lower lobe and a ventral notch near the tip of the upper lobe.

Demographic, Distribution, Habitat, Environment and Range: The Coral catshark can be found in the Indo-west Pacific in Pakistan and India to New Guinea and southern China. They can be found in crevices and in holes on coral reefs, its slender body is perfectly designed to navigate the cracks. They are shallow-water dwelling, typically not exceeding 49 feet deep.

Diet: They eat small fish and invertebrates.

Aesthetic Identification: The Coral catshark is cylindrical, slender, firm and dark in appearance. There are no clear saddle markings. There are enlarged black spots that often merge to form dash and bar marks bridging saddle areas. There are scattered large white spots on the sides, back and fin margins. The ventral side is white. There are 5 pairs of gill slits. The dorsal fins are much larger than the anal fin. The origin of the first dorsal fin is opposite or slightly in front of the pelvic fin insertions. The first dorsal fin is angled backwards. The second dorsal fin is similarly shaped and slightly smaller than the first, and originates over the front quarter of the anal fin base. The pectoral fins are fairly large. Adult males have long, thin claspers that extend about two-thirds of the distance between the pelvic and anal fins.

Biology and Reproduction: They are oviparous, laying pairs of egg cases that are shaped like a purse. Each egg case has two constricted “waists”; one end of the capsule is squared off while the other has two short “horns” that may terminate in short tendrils. The female deposits the eggs on the bottom, rather than attaching them to vertical structures. The capsule is light brown when freshly laid and darkens over time.

The young hatch after 4–6 months at 79 °F. The young have a contrasting dorsal pattern of light and dark vertical bars, sometimes with black and white dots. At three months old, the young have grown by 1.6–2.0 inches and their coloration has faded to match that of the adults.

Captive individuals have been known to live up to 20 years, and have reproduced in aquariums.

Behavioral Traits, Sensing and Intelligence: They are crepuscular and nocturnal; inactive and reclusive during the day and active during dusk and night. They finish their foraging just before sunrise, to return to rest, and many times will return to the same resting place many days in a row: the same hole or crevice. They do not crawl like Epaulette sharks and some other species. Captive specimens have been observed lying still and lunging at prey that come into range.

 In captivity, they have been observed as aggressors over other smaller sharks, even witnessed attacking sharks that are almost equal in size.

Coral Catshark Future and Conservation: They are near threatened. They are common in artisanal fisheries. They are quite common in aquaria.  Its habitat is also near threatened in much of its range due to habitat degradation from blast fishing, pollution, and the mining of coral for use as building material.

Small numbers of coral catsharks are caught incidentally by artisanal reef fishers in eastern Indonesia and likely elsewhere; it may be sold for meat or processed for fishmeal and liver oil, but its size limits its economic importance.

The Coral catshark adapts well to captivity and has reproduced in the aquarium. Private aquarists seek this shark, claiming it is one of the most suitable species.

Coral Catshark Recorded Attacks on Humans: Not a threat to humans.