Author: (Müller and Henle, 1839)
A small, very slender, light grey or greybrown shark with horizontally oval eyes and internal nictitating eyelids, nostrils with slender barbels but no nasoral grooves, mouth long, arched and reaching past anterior ends of eyes, labial furrows very long, small cuspidate teeth, two small, spineless, equal-sized dorsal fins and an anal fin, the first dorsal fin on the back between pectoral and pelvic fins, no precaudal pits, and the caudal fin without a strong ventral lobe or lateral undulations on its dorsal margin.
Head without laterally expanded blades; eyes horizontally oval, with lengths less than 2 times height; nictitating eyelids internal; spiracles present and very small; anterior nasal flaps formed into slender barbels; internarial width about 2.5 to 3.2 times the nostril width; labial furrows very long; teeth small, with acute narrow cusps, lateral cusplets, and strong basal ledges and grooves, not bladelike and similar in both jaws; posterior teeth not comblike; tooth rows 49 to 60/43 to 54. Precaudal pits absent. First dorsal fin small and not keel-like, much shorter than caudal fin; first dorsal base well ahead of pelvic bases, slightly closer to pectoral bases than pelvics; pectoral fins with radials confined to bases of fins; ventral caudal lobe absent or very weak; no undulations or ripples in dorsal caudal margin. Neurocranium without supraorbital crests; vertebral centra with strong, wedge-shaped intermedial calcificiations. Valvular intestine with a spiral valve of 14 to 16 turns. Colour grey above, light below, no colour pattern. Development viviparous, with a unique globular placenta.
Eastern Atlantic: Mauritania to Angola, possibly north to Morocco and Mediterranean.
Habitat and Biology:
This is a small, common, inshore tropical shark of the West African continental shelf, found near the bottom at depths of 10 to 75 m. It is especially abundant off river mouths, prefers muddy bottoms. Water temperatures where it occurs range from 20 to 27°C; salinities from 35 to 36°/oo; oxygen from 3 to 4 ppm. Nothing is known of the behaviour of this little shark, which apparently has never been kept in captivity. Its firm skin and muscles, long strong tail, rather short body caviity and small liver all suggest that it is an active swimmer rather like smooth-hounds (Mustelus, Family Triakidae).
Viviparous, with a unique spherical or globular placenta; two females had litters of 7 young. Pregnant females are found with young from July to October off Senegal, with largest fetuses (up to 20 cm) occurring in October. Presumably the gestation period is at least 4 months.
An unusual morphological feature of the barbeled houndshark is pronounced sexual heterodonty or dental sexual dimorphism. Males have greatly enlarged anterior teeth, possibly of use in courtship and copulation.
This species is a generalized feeder on small bottom and littoral organisms with a preference for crustaceans. and eats a variety of small bony fish including sardines, anchovies, snake eels, blennies, gobies, and flatfish, as well as skate and flyingfish eggs, crabs, shrimp, lobsters, octopi and sponges. It occasionally swallows inedible objects such as feathers and vegetable debris (including flowers).
Maximum 82 cm; males probably maturing at about 55 to 60 cm and definitely adult at 56 to 77 cm; females maturing at or above 52 cm and definitely adult at 58 to 82 cm; size at birth probably above 20 cm.
Interest to Fisheries:
Probably important to inshore artisanal fisheries in the West African area, where it is taken with hook and line as well as fixed bottom gillnets; also caught by commercial bottom trawlers. Its flesh is utilized fresh, smoked, or dried salted for human consumption and its skin is used for leather.
Holotype: British Museum (Natural History), stuffed adult male. Type Locality: "Kabendabay" (Cabinda Bay, Cabinda, Angola).