Atlantic sawtail catshark

The original description of the Atlantic sawtail catshark, as Pristiurus atlanticus, was published in 1888 by French naturalist Léon Louis Vaillant, in . Vaillant based his account on a specimen caught at a depth of off Cape Spartel in northwestern Morocco. This species was long thought to be the same as the closely similar blackmouth catshark (G. melastomus), until it was resurrected by Ramón Muñoz-Chápuli and A. Perez Ortega in 1985. Castilho and colleagues (2007) further affirmed the distinction between G. atlanticus and G. melastomus using morphometric and mitochondrial DNA data. ==Distribution and habitat==

The Atlantic sawtail catshark is found from Cape St. Vincent in southwestern Portugal, through the Strait of Gibraltar into the Alborán Sea, to as far as Cabo de Gata in southwestern Spain. It is most abundant in the center of the Alborán Sea, and around Isla de Alborán. This species has been recorded a few times off Morocco and once off Mauritania; it may be extremely rare or mistaken for G. melastomus in the region. There is a lone record from shallower than . This species does not exhibit spatial segregation by either sex or size, or conduct seasonal migrations. ==Description==

The Atlantic sawtail catshark reaches a maximum known length of . The first dorsal fin is positioned over the latter portion of the pelvic fin bases, while the second is positioned over the latter portion of the anal fin base. Both dorsal fins are angular and similar in size. The pectoral fins are large and wide, with rounded corners. The short, low pelvic fins are placed close to the anal fin, which is elongated and angular. The caudal peduncle is compressed from side to side; its height is greater than in G. melastomus, exceeding 4.5% of the total length. The caudal fin is low, with a small lower lobe and a ventral notch near the tip of the upper lobe. The skin is covered by dermal denticles, each with a leaf-shaped crown bearing a median ridge and three marginal teeth. A prominent crest of enlarged denticles runs along the front portion of the dorsal caudal fin margin. The coloration is gray above and pale below, with a series of dark gray saddles or blotches along the back and tail. The dorsal fins are dusky at the base and lighten towards the trailing margins. The trailing margin of the caudal fin is black, as is the interior of the mouth. ==Biology and ecology==

The Atlantic sawtail catshark is rarer than the blackmouth catshark, which shares its range. Its natural history is poorly understood. Reproduction is oviparous, with mating and spawning proceeding throughout the year. Females can contain up to nine maturing eggs at a time, divided between the two functional oviducts. The tough egg case is flask-shaped and reddish, with a rounded bottom and a pair of "horns" at the top, and measuring around long and across. The egg case of G. melastomus is similar in appearance but significantly larger. Rey and colleagues (2010) reported the smallest mature males and females in their study to be and long respectively. ==Human interactions==

Fishery data for the Atlantic sawtail catshark is inadequate as it is still recorded as G. melastomus by observers. This species is caught incidentally on deepwater longlines and bottom trawls targeting other species, including wreckfish (Polyprion americanus), conger eel (Conger conger), Norway lobster (Nephrops norvegicus), and red shrimp (Aristeus antennatus). Most landed sharks are discarded and likely suffer high mortality due to damage sustained during capture; the larger specimens are marketed for human consumption. Given the small extent of its range and the ubiquitous heavy fishing pressure within, the International Union for Conservation of Nature (IUCN) has assessed this shark as Near Threatened. ==References==