Sympterygia bonapartii

Common Name

Smallnose Fanskate

Year Described

Müller & Henle, 1841

Identification

Median thorns: 21

Disk heart shaped with broad, rounded pectoral fins and a weakly concave anterior margin of disk. Snout short, broad and soft with almost straight lateral edges. Skin mostly smooth with patches of prickles on outer pectoral fins and anterior disk/head. Ventrum quite smooth.. There are single pre-orbital and post-orbital thorns. No scapular thorns. There are 2-6 nuchal thorns. A single row of thorns on midline from back of head to the first dorsal fin. Tail thick and about length of disk. Caudal fin low. Dorsal fins are paired far back on tail and have a single thorn between them. Pelvic fins with a weak notch. Claspers large and broad. Mouth narrow. Teeth are conical and sharp (~35).

Color

Body pale brown with closely spaced dark round blotches giving the appearance of reticulations. Large patch of coalesced blotches on middle of pectoral fin creates a larger dark blotch there and often around the outer edge of disk. Belly pale with a dark snout.

Size

Maximum size to 88cm TL.

Habitat

Found mostly in coastal waters (<100m) but rarely deeper.

Range

Southwestern Atlantic: S. Brazil to Tierra del Fuego. Also S. Chile.

References

Last, P.R., White, W.T., Carvalho, M.R. de, Séret, B., Stehmann, M.F.W & Naylor, G.J.P (Eds.). 2016. Rays of the World. CSIRO Publishing, Melbourne.

Other Notes

Two other species of Sympterygia, S. brevicaudata and S. lima, from the Pacific coast are differentiated by the number of thorns on the midline. They have yet to be recorded from Atlantic Patagonia.