A catshark with a flat-head appearance and counter-shaded body

The Flathead catshark (Apristurus macrorhynchus) is a shark belonging to the family Scyliorhinidae found in the deep waters of the northwest Pacific Ocean. They are oviparous, but not much is known about this shark.


Family: Scyliorhinidae – Catsharks

Genus: Apristurus 

Species: macrorhynchus


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Scyliorhinidae

Common NameCatsharks




Average Size and Length: Their measurements are mostly unknown. An adult female was measured at a maximum of 66 cm/2.2 feet.

Teeth and Jaw: The mouth is short and arched. The labial furrows are long. The uppers reach the symphysis and the lowers are shorter. The teeth are small and wide spaced and almost burr-like. Each tooth has 3 cusps.

Head: The head is broad and flattened. The snout is round and elongated with large nostrils. The mouth extends to the anterior ends of the eyes. The eyes are small, oval and cat-like.

Tail: The caudal fin is elongated.

Demographic, Distribution, Habitat, Environment and Range: The Flathead catshark is found in the northwest Pacific off the coast of Japan from southeastern Honshu to Okinawa Trough. They have also been recorded off China and Taiwan Island. They can be found around islands over continental slopes on the sea bed in deep water between 722-3,740 feet. They are considered bathydemersal.

Aesthetic Identification: The Flathead catshark is light grey to grey-brown dorsally and white ventrally and on the fins. The gill slits are fairly small. They are smaller than the adult eye length. The first dorsal fin originates over the last quarter of the long pelvic fin bases. Which is two-thirds the side of the second dorsal fin. It is separated by a space greater than the first dorsal base. The anal fin is elongated and large. It is separated from the caudal fin by a small notch.

Biology and Reproduction: They are oviparous laying pairs of eggs.

Behavioral Traits, Sensing and Intelligence: Unknown, but could be nocturnal.

Flathead Catshark Future and Conservation: They are not evaluated but probably discarded by deepwater trawls as bycatch.

Flathead Catshark Recorded Attacks on Humans: Not a threat to humans.