Whitespotted bamboo shark - Chiloscyllium plagiosum

The whitespotted bamboo shark Chiloscyllium plagiosum is a small elongated bottom shark in the Orectolobiformes. Within the Hemiscylliidae it belongs to the genus Chiloscyllium; on Haitauchen it is also framed within Selachii and Galeomorphi.

FishBase describes it as a reef-associated marine shark from 0 to 50 m depth. Standard summaries give about 83 cm for males or unsexed animals and up to about 95 cm for females; many adults are smaller, around 60 to 80 cm.

Key identification traits

Key traits are the dark brown to grey-brown base colour, dark crossbands, many irregular white to bluish spots, spiracles below the eyes and short barbels near the nostrils. The tail fin has a marked subterminal notch but no developed lower lobe.

Confusion is most likely with other Chiloscyllium species. In the field, the white spots, dark bands and lack of a large black eyespot behind the pectoral fins are the most useful clues.

The species lives in the tropical and subtropical Indo-West Pacific. Florida Museum lists records from South Asia through Southeast Asia to Japan, Taiwan and the Philippines; Haitauchen currently links it with Bangladesh, China, India, Indonesia, Japan, Cambodia, Malaysia, Myanmar, Papua New Guinea, Philippines, Singapore, Sri Lanka, Taiwan, Thailand and Vietnam.

Ecologically, the whitespotted bamboo shark connects the Indian Ocean with the western Pacific Ocean. Sources differ on some edge records and older reports, so local records should ideally be read with photograph, depth and habitat.

Shallow coastal habitats

Typical habitats are shallow rocky and coral reefs, lagoons, sheltered coasts and structured bottoms with crevices, overhangs or rubble. This is not a wide-ranging open-ocean shark, but a bottom shark whose encounters depend strongly on quiet, shallow coastal habitat.

The whitespotted bamboo shark is mostly nocturnal. By day it often rests on the bottom, under structure or inside crevices; at night it searches slowly across reef, rock and sand for food.

Shark-References summarizes it as an inshore bottom shark that feeds mainly on small bony fishes and crustaceans. Its teeth are not built for large prey, but for gripping soft animals and crushing harder food on the bottom.

Eggs, young sharks and nocturnal activity

Like other bamboo sharks, Chiloscyllium plagiosum is oviparous. Eggs are laid in pairs, and embryos develop on yolk. Hatchlings are very small and already live close to the bottom as miniature versions of the adults.

Seasonal patterns are known from Taiwan, with mating in winter, egg laying in spring and hatching in summer. Such data should be read regionally because temperature, coast type and husbandry conditions can shift the timing.

The IUCN Red List lists the whitespotted bamboo shark as Near Threatened. That fits a species with a broad Indo-West Pacific range but a strong dependence on shallow coastal and reef habitats.

Important pressures include hook, trawl and inshore net fisheries, local use for food or traditional products, habitat pressure in shallow reefs and lagoons, and confusion with other small bamboo sharks.

Main pressures

Protection therefore means reducing bycatch in shallow coastal habitats, improving species identification in markets and landings, and keeping structurally rich reef and lagoon areas intact.

The whitespotted bamboo shark is harmless to people. It is small, bottom-living and focused on small prey; conflict is mainly possible when an animal is held, pulled from a crevice or harassed for photographs.

The U.S. Fish & Wildlife Service lists the species under the common name whitespotted bamboo shark. It is relatively familiar from public aquariums because its calm bottom life, egg laying and moderate size make it easy to observe.

Diving encounters

For night dives, approach slowly, leave the shark an exit route, do not touch or lift it, and use light sparingly. Good photos with place, depth and habitat are useful because they reduce identification errors.

For Haitauchen, Chiloscyllium plagiosum stands for the quiet shark encounters of shallow tropical reefs: not a large show shark, but a small bottom hunter whose protection is tied to healthy coastal reefs and respectful underwater behaviour.