Whitespotted Bamboo Shark: Chiloscyllium plagiosum

Family: Hemiscylliidae
Common name(s)

Whitespotted Bamboo Shark, White-spotted Carpetshark.

Identification

Rounded snout. Snout length roughly equal to mouth width. Short barbells extend from nasal openings to mouth level. Spiracle equal in size with eye. Short gill slits. A lateral groove on each flank runs from behind head to base of tail. Dorsal fins have straight or mildly convex posterior margins and acutely rounded tips. First dorsal origin over pelvic fin insertion. Second dorsal almost as large as first. Anal fin low and rounded; positioned directly before lower caudal lobe. Caudal fin long and thin, with long, low, rounded lobes.
Dorsal coloration grey, tan or brown with 8 or 9 irregular dark saddles and small light spots. Ventrum slightly paler than flanks.

Size

Maximum size 95cm. Size at birth less than 9-12cm.

Habitat

Shallow tropical coral reefs. From inshore to at least 20m (personal observation).

Distribution

From India westwards throughout Southeast Asia, including some islands in southern Japan.
Records of whitespotted bamboo sharks from  Madagascar refer to a soon be resurrected species; Chiloscyllium caerulopunctatum.

Conservation Status

NEAR THREATENED

The majority of the distribution of the Whitespotted Bamboo Shark is under substantial, generally unregulated and unmanaged fishing pressure. The species is landed and utilised for human consumption in nearly all countries within its range. The species is known to be taken regularly in India, Thailand and China (Compagno 2001) and is landed in Borneo (Manjaji 2002), Philippines (Compagno et al. 2005), Taiwan (both on the mainland and the Penghu Islands) (P. Kyne pers. obs., D. Ebert pers. comm.) and irregularly in Indonesia (W. White pers. comm.). It is also prized for the aquarium trade as it is hardy in captivity and known to survive for long periods in aquaria (Michael 1993, Compagno 2001).
Pressure on coral reef systems is high over much of the species’ range with the amount of available habitat being reduced in recent history due to the degradation/destruction of coral reefs through such practices as dynamite fishing (e.g., Indonesia and elsewhere) and terrestrial runoff (e.g., through logging in Philippines).
Given human population increases in the Asian region and continued and increasing exploitation of marine resources the conservation status of this coral reef species is of concern.

Citation
Kyne, P.M. & Burgess, G.H. 2006. Chiloscyllium plagiosumThe IUCN Red List of Threatened Species 2006: e.T60222A12325334. https://dx.doi.org/10.2305/IUCN.UK.2006.RLTS.T60222A12325334.en. Downloaded on 27 December 2020.

Reproduction

Oviparous. About 26 egg cases are laid each year. In captivity, females deposit two egg capsules at a time, on average every 6 to 7 days from spring to summer (Masuda 1998), or about every six days from winter to spring (Miki 1994). The eggs hatch between 110 to 135 days after being deposited on the reef.

Diet

Feeds on bony fishes and crustaceans.

Behavior

Nocturnal. Rests by day in crevices on the reef or under corals.

Reaction to divers

Easy to approach with slow casual movements. Will bolt if molested.

Diving logistics

Although whitespotted bamboo sharks occur throughout most of southeast Asia, they are infrequently seen by divers. This may be because they are relatively scarce or because they tend to be quite secretive; resting by day in deep crevices.

Malapascua Island in the Philippines seems to have a reasonable population of whitespotted bamboo sharks. Patiently moving along the reef, searching under plate corals in the 10-20m depth range should be successful.

They are also seen fairly regularly at dive sites around the islands in the south of Japan.

Similar species

No other bamboo sharks have complex markings in their adult stage.