Atlantic sawtail catshark

The Atlantic sawtail catshark (Galeus atlanticus) is a little-known species of deepwater catshark, belonging to the family Pentanchidae, found in a small area of the northeastern Atlantic Ocean, centered on the Strait of Gibraltar and the Alborán Sea. It is found on or close to the bottom over the continental slope, mostly at depths of 400–600 m (1,300–2,000 ft). This shark closely resembles, and was once thought to be the same species as, the blackmouth catshark (G. melastomus); both are slender with a series of dark saddles and blotches along the back and tail, and a prominent crest of enlarged dermal denticles along the dorsal edge of the caudal fin. It differs subtly from G. melastomus in characters including snout length, caudal peduncle depth, and the color of the furrows at the corner of its mouth.

Reproduction in the Atlantic sawtail catshark is oviparous, with females carrying multiple maturing eggs at once. Mating and spawning occur year-round. This species is caught incidentally by commercial deepwater fisheries throughout its range, but the impact of fishing pressure on its population is uncertain as it is not recorded separately from G. melastomus. Given its restricted distribution, it has been assessed as Near Threatened by the International Union for Conservation of Nature (IUCN).