Triakis scyllium

Author: Müller and Henle, 1839

Field Marks:
A moderately slender houndshark with a short broadly rounded snout, lobate anterior nasal flaps that do not reach the mouth and are far separated from each other, long upper labial furrows that reach the lower symphysis of the mouth, teeth partially bladelike, with strong, erect to oblique cusps on all teeth and well-developed cusplets, relatively narrow fins, and scattered black spots.

Diagnostic Features:
Teeth with strong cusps and cusplets on almost all teeth, not semimolariform, lateroposterior teeth bladelike, with strongly oblique cusps. Pectoral fins broadly triangular in adults. First dorsal fin with nearly vertical or posteroventrally sloping posterior margin. Total vertebral counts 149 to 155. Body with sparsely scattered small black spots and broad dusky saddles in young, spots fading and sometimes absent in adults.

Geographical Distribution:
Western North Pacific: Southern Siberia, Japan, the Koreas, China (including Taiwan Island), ? The Philippines.

Habitat and Biology:
A common to abundant, temperate bottom-dwelling shark of the continental and insular shelves of the Western Pacific, often occurring in shallow water close inshore, on or near the bottom. Favours estuaries and shallow bays, especially sandy and algal-covered areas and eelgrass flats; apparently tolerant of reduced salinities. Seldom gregarious, though some may cluster in resting areas on bottom.

Ovoviviparous, without a yolk-sac placenta; number of young 10 to 20 per litter.

Feeds on small fishes and probably crustaceans and other bottom invertebrates.

Size:
Maximum size at least 150 cm, males maturing between 99 and 108 cm.

Interest to Fisheries:
Apparently commonly fished off Japan and probably the Koreas and northern China. Details are not known by the writer but its meat is apparently regarded as of inferior quality to other houndsharks in Japan.

Remarks:
Synonymy of Hemigaleus pingi with this species follows Compagno (1979). Philippines records for this shark are doubtful. Four late fetal specimens in the Stanford University Fish Collection from the Philippines identified as T. scyllium by A.W. Herre, their collector, turned out to be an undescribed species of Hemitriakis (see Compagno, 1970, 1979).

Type material:
Holotype: Rijksmuseum van Natuurlijke Historie, Leiden, dried specimen ? Type Locality: Japan.

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