CRCritically Endangered

Cephaloscyllium sarawakensis

Cephaloscyllium sarawakensis, commonly known as the Sarawak swellshark, is a small benthic shark species endemic to the waters off Sarawak, Malaysian Borneo. This catshark belongs to the family Scyliorhinidae and is characterized by its ability to inflate its body when threatened, a defensive mechanism typical of swellsharks.

Decreasing

Population trend

8

Countries

01Classification

Taxonomy & Classification

Kingdom

ANIMALIA

Phylum

CHORDATA

Class

CHONDRICHTHYES

Order

CARCHARHINIFORMES

Family

SCYLIORHINIDAE

Genus

Cephaloscyllium

Cephaloscyllium sarawakensis belongs to the family SCYLIORHINIDAE, order CARCHARHINIFORMES, within the CHONDRICHTHYES class.

02Description

Species Profile

Cephaloscyllium sarawakensis, commonly known as the Sarawak swellshark, is a small benthic shark species endemic to the waters off Sarawak, Malaysian Borneo. This catshark belongs to the family Scyliorhinidae and is characterized by its ability to inflate its body when threatened, a defensive mechanism typical of swellsharks. The species inhabits continental shelf waters at moderate depths, where it feeds on small fish, crustaceans, and other benthic invertebrates. As a bottom-dwelling species with limited mobility and a restricted geographic range, the Sarawak swellshark faces significant conservation challenges. The primary threats to this species include intensive fishing pressure from both commercial and artisanal fisheries operating in its limited range. Bottom trawling activities pose a particular risk, as they directly impact the seafloor habitats where these sharks live and feed. Habitat degradation from coastal development, pollution, and sedimentation further compounds the pressures on remaining populations. The species' naturally low reproductive rate, typical of sharks, limits its ability to recover from population declines. Currently, there are no specific conservation measures in place for this species, though it may receive some indirect protection through general marine protected areas in Malaysian waters. Research efforts to better understand its ecology, population status, and specific habitat requirements are critically needed to develop effective conservation strategies for this endangered endemic shark.

The Sarawak swellshark faces severe pressure from intensive fishing activities, particularly bottom trawling, within its limited geographic range off the coast of Malaysian Borneo. Habitat degradation from coastal development, pollution, and sedimentation further threatens the seafloor environments where this species lives and feeds.

Key Facts

IUCN StatusCritically Endangered (CR)
TrendDecreasing
GroupFishes
03Habitat

Habitat & Distribution

This species inhabits continental shelf waters off Sarawak, Malaysian Borneo, living on or near the seafloor at moderate depths. It occupies benthic environments where it can find shelter and prey on small fish, crustaceans, and other bottom-dwelling invertebrates.

MARINEMajor
04Threats

Threats

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IUCN Red List: Critically Endangered

The Sarawak swellshark faces severe pressure from intensive fishing activities, particularly bottom trawling, within its limited geographic range off the coast of Malaysian Borneo. Habitat degradation from coastal development, pollution, and sedimentation further threatens the seafloor environments where this species lives and feeds.

Fishing & harvesting aquatic resources

Ongoing

Hunting & trapping terrestrial animals

Ongoing

Intentional use: hunting/trapping

Ongoing

Invasive non-native/alien species/diseases

Ongoing

Logging & wood harvesting

Ongoing

Marine & freshwater aquaculture

Ongoing

Other ecosystem modifications

Ongoing
05Conservation

Conservation Actions

Species recovery
Awareness & communications
Policies and regulations
Compliance and enforcement
Community

Community Sightings

Report a sighting

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

This page: SpeciesRadar (2025). Cephaloscyllium sarawakensis (Cephaloscyllium sarawakensis). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/sarawak-pygmy-swell-shark

Full citation guide & data usage terms