Author: Cloquet, 1821
Field Marks:
A large, white-spotted Mustelus with a relatively narrow internarial space,buccopharyngeal denticles covering almost entire oral cavity, unfringed dorsal fins, relatively small pectoral and pelvic fins, and 90 to 100 precaudal centra. It is the only white-spotted smooth-hound in European waters.
Diagnostic Features:
Body fairly slender. Head short, prepectoral length 13 to 17% of total length; snout moderately long and bluntly angular in lateral view, preoral snout 5.4 to 7.2% of total length, preorbital snout 5.7 to 7.2% of total length; internarial space fairly narrow, 2 to 2.6% of total length; eyes large, eye length 1.6 to 2.2 times in preorbital snout and 2.5 to 4.1% of total length; interorbital space relatively narrow, 3.4 to 4.5% of total length; mouth relatively short, subequal or smaller than eye length, its length 2.2 to 3.5% of total lenuth; Upper labial furrows considerably longer than lowers, upper furrows 1.8 to 2.5% of total length; teeth molariform and asymmetric, with cusp reduced to a low point, cusplets absent except in very young sharks; buccopharyngeal denticles covering entire palate and floor of mouth. Interdorsal space 19 to 25% of total length; trailing edges of dorsal fins denticulate, without bare ceratotrichia; pectoral fins moderate-sized, length of anterior margins 12 to 16% of total length, width of posterior margins 7.8 to 13% of total length; pelvic anterior margins 6.6 to 9.1% of total length; anal height 2.4 to 3.9% of total length; anal-caudal space usually greater than second dorsal height, 6.8 to 11% of total length; ventral caudal lobe not falcate in adults. Crowns of lateral trunk denticles broadly lanceolate, with longitudinal ridges extending at least half their lengths. Skeleton not hypercalcified in adults; palatoquadrates not subdivided; monospondylous precaudal centra 36 to 40, diplospondylous precaudal centra 49 to 61, precaudal centra 90 to 100. Colour grey or grey-brown, above, light below, usually with numerous small white spots on sides and back, but without dark spots or dark bars. Development ovoviviparous. Size large, adults 80 to 140 cm.
Geographical Distribution:
Eastern North Atlantic: British Isles and North Sea to Canary Islands, Mediterranean and Mauritania.
Habitat and Biology:
A common inshore and offshore shark of the continental and insular shelves, on or near the bottom at depths from the intertidal down to at least 100 m. Prefers sandy and gravelly bottoms.
Ovoviviparous, without a yolk-sac placenta; number of young 7 to 15 per litter, with litter size proportionate to maternal size. The gestation period is about 12 months. Young are dropped inshore in summer, and presumably mating occurs in the same season. From growth-curve data it has been suggested that this species is fast-growing, maturing at an age of two to three years, but this has not been confirmed with direct ageing methods such as calibrating vertebral rings.
Primarily a crustacean feeder, that eats crabs, hermit crabs, lobsters and slipper lobsters. Hermit crabs are eaten complete with the whelk shells they live in and sometimes with the commensal sea anemones that live on their shells.
Size:
Maximum about 140 cm, males maturing between 78 and 85 cm, females at about 85 cm; size at birth about 30 cm.
Interest to Fisheries:
Caught by bottom trawls, line gear, and probably gillnets; utilized fresh and probably dried salted; also taken by shore anglers.
Remarks:
This species is very similar to other Eastern Hemisphere smooth-hounds with white spots and oviviviparous reproduction, including M. manazo, M. antarcticus, M. lenticulatus, and M. palumbes. All of these species are allopatric to M. asterias, but, according to Heemstra (1973 and pers. comm.), all are distinct if littledifferentiated. M. manazo is most similar, but differs in being smaller and in having fewer vertebrae; M. lenticulatus and M. antarcticus have broader internarials and less extensive buccopharyngeal denticles; and M. palumbes has larger paired fins, a broader internarial, and somewhat fewer vertebrae. The white-spotted smoothhounds from the Western Hemisphere, M. mento and M. schmitti, are very different from M. asterias and can be distinguished from it in the key to species.
Type material:
Holotype: None. Type Locality: None mentioned.