Spotted-Belly catshark

Recently described catshark in Indonesia

The Spotted Belly catshark (Atelomycterus erdmanni) is a species of shark belonging to the family Scyliorhinidae. It is found in eastern Indonesia. It is a more recently described catshark, having several similarities to its family members, but clear and identifiable differences.


Family: Scyliorhinidae – Catsharks

Genus: Atelomycterus 

Species: erdmanni


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Scyliorhinidae

Common NameCatsharks




Average Size and Length: Males have been recorded at 50.1 cm/1.6 feet and female at 50.8 cm/1.7 feet.

Head: They have a relatively short snout between 3.4-3.8% of the total length. The head length is between 17.5-17.9% of the total length.

Denticles: They have strongly tricuspid denticles with an elongate medial cusp.

Demographic, Distribution, Habitat, Environment and Range: The Spotted-Belly catshark can be found in the western Pacific in Indonesia. They are tropical, reef-associated found at a depth of between 9-203 feet.

Aesthetic Identification: The color pattern of the Spotted-Belly catshark has dark brown to black and white spots and blotches, and faint dark brown saddles. The white spots are surrounded by 2-4 dark spots. The dark spots are scattered along most of the ventral surface, which is less distinct in males. A distinct white stripe runs through the upper third of the gill slits.

The Spotted-Belly catshark differs from the Bali catshark in having white spots present over the body, it has a larger first dorsal fin, paired fins closer together, and pelvic fins farther apart from the ventral caudal-fin origin. The Spotted-Belly catshark differs from the Coral catshark in having far less numerous white spotting, a larger first dorsal fin, and the clasper glans about half length of clasper outer margin.

The precaudal length is between 76.6-79.1% of the total length. The interdorsal space is between 13.4-13.7% of the total length. The distance between the pectoral and pelvic fins and pelvic to anal fins is about equal. The ratio of the pectoral-pelvic and pelvic-anal is between 1.01-1.02. The anal-fin length to anal-fin base ratio is 1.29. They have moderately falcate dorsal fins with posterior margins sloping anteroventrally from fin apices.

Reproductive System: The claspers of the adult males are relatively short; the outer length is 9% of the total length. The clasper base width is 15.5% of the clasper outer length, they are not stubby, not tapering from base to tip. The clasper glans extends to about half of the clasper outer length. The cover of the rhipidion is relatively narrow. The rhipidion is moderately large, partly concealed by the cover of the rhipidion and exorhipidion. The pseudosiphon is about half the length of the cover of the rhipidion. The clasper tip is narrow and bluntly pointed.

Biology and Reproduction: Not much is known, but they are more than likely oviparous.

Behavioral Traits, Sensing and Intelligence: Not much is known about their behavior, but they have been observed by dive operators in North Sulawesi and Ambon on night dives at depths of 9-49 feet, so more than likely they are nocturnal.

Spotted-Belly Catshark Future and Conservation: Not evaluated.

Spotted-Belly Catshark Recorded Attacks on Humans: Not a threat to humans.