Common Name
Onefin Skate
Year Described
McEachran & Compagno, 1980
Identification
Disk rhomboidal with a concave anterior margin and convex posterior margin. Snout moderate with stiff rostral cartilage. Tip of snout blunt with a filamentous tab. Pectoral fins with angular tips. Pelvic fin consists of a single lobe with hook-like anterior lobe and scalloped margin. Tail is extremely long and thin. Side of tail with narrow skin folds that broaden at tail tip. A single dorsal fin. Caudal fin with equal lobes bisected by tail. Eyes and mouth large. Jaws with 25-45 tooth rows. Male claspers thin and long.
Body is covered with dermal denticles dorsally. Males have curved alar thorn patch. Ventrum smooth. Thorns present in two bands adjacent to midline and some additional rows on flanks. Thorns when present are more like enlarged dermal denticles and not very obvious.
Color
Dorsum brownish with irregular brown bloches and spots. Tail with 6-8 brown bands. Ventrum pale with brownish disk edging.
Size
Maximum size to 53cm TL.
Habitat
Known from deep continental slope waters from 400-800m.
Range
Taken from northern and southern Brazil.
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
Easily differentiated from other family members by having a single dorsal fin.