Diagnosis

A moderately-sized dogfish with two spined dorsal fins and no anal fin. First dorsal fin spine almost equal in height to the apex of the fin; second dorsal fin spine taller than fin (compare with S. acanthias) and often measuring more than 6% of TL. First dorsal fin origin above pectoral inner margins. Small lateral keels on lower sides of caudal peduncle; precaudal pit present; caudal fin without subterminal notch. No white spots on body.  Dorsal colour grey or grey-brown, often rather sandy; dorsal fins with lighter edges, especially in juveniles; ventral surfaces paler or white.

Size

Maximum ca. 100cm; mostly less than 90cm; size at birth about 23cm.

Status and Distribution

N.E. Atlantic: From the Bay of Biscay (not common) southwards along the Iberian coast where abundance increases; N.W. African coasts from Morocco through Western Sahara and Canary Islands to Senegal and Cape Verde; range extends through African equatorial waters where these sharks are sympatric with other very similar spurdogs (shortnose spurdog Squalus megalops and shortspine spurdog S. mitsukurii), with which they may be readily confused.
Mediterranean Sea: Very common. Entire Mediterranean, Sea of Marmara and Black Sea.

Biology

Longnose spurdogs are a common species found in warmer waters (above 10C) than S. acanthias but over similar substrates and depths; ranging from the intertidal to at least 440m over gently shelving sandy or muddy bottoms, especially near offshore banks on continental slopes where these sharks may readily form large schools. Feeding ecology similar to the piked dogfish, taking a variety of small teleosts including mackerel, sometimes cephalopods such as squid; also crabs, lobsters and other benthic invertebrates. Ovoviviparous, with 3 to 9 embryos; one litter born every two years. Females mature at ca. 60cm; males at ca. 50cm.