Common Name
Spined Pygmy Shark
Year Described
Smith and Radcliffe, 1912
Identification
Teeth: 22-23 upper, 16-21 lower. Upper teeth slender and erect. Lower teeth slightly larger with oblique cusps.
Body torpedo-shaped and strongly tapering posteriorly. Head large. Snout longer than orbit diameter. Nostrils under snout. Mouth small with upper labial furrows, very long post-oral grooves, and thin fringed lips. Eyes large. Five gill slits short. Two dorsal fins spaced widely. First dorsal fin placed about at mid-body (above pectoral tip) and with a tiny spine. Second dorsal fin much longer than first and lacks a spine. Pectoral fin moderate and squared off. Pelvic fin well posterior and larger than first dorsal fin. Anal fin absent. Caudal fin with a paddle-like upper lobe and and pronounced lower lobe. Skin rough. Denticles small squares with deep interspaces and small depressions in center.
Color
Body dark brown overall with a darker belly. Ventral surface assumed to be bioluminescent. Most of fins except caudal whitish. Caudal fin brown with a pale margin. Pectoral fin with brown blotch at tip. Eye green.
Size
Maximum size to 28cm TL. Mature adults 15-20cm TL, making it one of the smallest known sharks.
Habitat
Epipelagic. Taken between 120-1800m but more common <500m to the surface. Vertically migrates (shallower at night).
Range
Known from off the U.S. east coast, Bermuda, the southern Gulf of Mexico, and off Brazil.
References
Castro, J.I. 2011. The Sharks of North America. Oxford University Press, 640 pp.
Ebert, D. A., & M. Dando. 2020. Field Guide to Sharks, Rays & Chimaeras of Europe and the Mediterranean. Princeton University Press. 2020.
Other Notes
The only spined member of this family.