Common Name
Eyespot Skate
Year Described
Regan, 1903
Identification
Nuchal median thorns: none
Tail median thorns: 7-10
Disk rhomboidal and entirely smooth. Ventrum smooth. Median thorn row lacking anterior to pelvic fin. Snout moderate with slightly convex anterior margins. Snout with semi-translucent window between pectoral origin and snout tip (unique to Atlantoraja and Rioraja). Anterior margin of pectoral fins concave. No ocular thorns. No scapular thorns. Alar thorn patch is elongated. Eyes small. Median row of tail thorns relatively few and interrupted (many missing in larger adults). Dorsal fins are small and separated by 1-3 interdorsal thorns. Pelvic fin notched with projecting anterior lobe and broad posterior lobe. Tail is about body length and slender, with small lateral folds. Caudal fin short but tall. Male claspers long; reaching dorsal fin. Teeth are conical and sharp.
Color
Dorsum various shades of light brown to reddish-brown. Two prominent ocelli present on base of pectoral fins consisting of two double black rings. Ocelli are larger than eye. Rest of body and tail with no obvious spots or markings. Sides of snout translucent. Ventrum pale gray with dark sensory pores.
Size
Maximum size to 75cm TL.
Habitat
A coastal species occurring over soft bottoms to a maximum depth of 320m.
Range
Southwestern Atlantic: Southern Brazil to northern Argentina.
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
The other smooth species of Atlantoraja, A. platana, has a different disk shape and never has an ocellus on the pectoral fin.