Common name(s)
Coral Catshark.
Identification
Long, slender body. Snout short and rounded. Mouth width greater than snout length. Lower labial furrows reach mouth cavity. Greatly enlarged nasal flaps extend rearward from nares to mouth. First dorsal fin origin level with midpoint of pelvic fin base. Second dorsal fin origin level with midpoint of anal fin base. First and second dorsal fins of roughly equal size, with rounded apexes. Lower caudal lobe indistinct. Dorsal coloration a striking pattern of bold black and white spots and blotches on a grey or grey-brown base. Fins usually have bold white tips/margins.
Size
Maximum length 70cm. Size at birth 10-13cm.
Habitat
A tropical catshark species inhabiting crevices in shallow coral reefs.
Distribution
The coral catshark is found from the coast of India, eastward throughout much of southeast Asia.
Conservation Status
NEAR THREATENED
Although A. marmoratus is widespread through the Indo-West Pacific, habitat destruction within its range, and increasing fishing pressure are likely to represent significant threats. This species may be under threat from habitat destruction by dynamite fishing, especially in eastern Indonesia, e.g., Tanjung Luar in Lombok (W. White, personal observation), and also maybe by coral removal in some parts of the region for use as building materials, e.g., Candi Dasa in Bali. Fisheries catches appear to be only minor throughout this species distribution, for example, it represents a minor catch in artisanal fisheries in several eastern Indonesian localities (W. White pers. obs.), and although it is probably caught in fisheries in West Papua and other parts of its range, information is very sparse. This species is close to the criteria of Vulnerable A2d+3d+4d due to the high level of exploitation within its range, but is assessed as Near Threatened due to the lack of detailed species composition data for fisheries and extent of habitat destruction in this region.
Citations and References
White, W.T. (SSG Australia & Oceania Regional Workshop, March 2003). 2003. Atelomycterus marmoratus. The IUCN Red List of Threatened Species 2003: e.T41730A10550175. https://dx.doi.org/10.2305/IUCN.UK.2003.RLTS.T41730A10550175.en. Downloaded on 10 November 2020.
Reproduction
Oviparous. Lays paired egg cases.
Diet
The coral catshark feeds on molluscs, crustaceans, as well as small fishes.
Behavior
Rests in deep crevices in the reef during the day. Forages on the reef at night, using it’s eel-like body to wriggle into small openings.
Reaction to divers
Usually quite shy, retreating deeper when disturbed inside crevices in the reef. Sometimes comes to rest in plain view, allowing close examination and photo ops. Not known to respond to bait.
Diving logistics
Although quite secretive, coral catsharks are fairly common on many reefs in southeast Asia that are too numerous to list here.
I have seen more coral catsharks while diving around Malapascua Island in the Philippines than anywhere else, but that may be just because on one trip, I was specifically looking in every crevice and under every coral head for catsharks and bamboo sharks.
There appear to lots of sightings from Lembeh Strait off Sulawesi but that may simply be because there is a disproportionately high number of photographers that go there.
Anywhere that you are aware coral catsharks occur, the best way to find one is to bring a good dive light and look in every crevice, and under every overhang on the dive. Remember to be careful of the fragile reef during your search.
Similar species
Australian Marbled Catshark Distinguished by more uniform light saddles and smaller black spots on a light brown base. Probably confined to northwestern Australia.
Bali Catshark Distinguished by subtle saddles and small black spots with light centres. Known only from Bali.
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