Dipturus olseni

Common Name

Spreadfin Skate

Year Described

Bigelow & Schroeder, 1951


Disk diamond-shaped with a straight to concave anterior margin. Snout fairly long (16-17% TL). Pectoral fins bluntly rounded. Anterior pelvic fin lobe about 50% as long as the posterior lobe. Tail is 51-53% of TL and has skin folds on both sides. There are two dorsal fins, separated from each other by a distance equal to first dorsal base. The caudal fin has both a dorsal and ventral lobe. Upper jaw with 34-41 tooth rows.

Body is smooth above and below, without dermal denticles. There are scattered orbital thorns on the head. No scapular thorns. No thorns on midline of body anterior to pelvic base. Tail with a median row of thorns, flanked with a lateral thorn row on each side of the tail. Three or more thorns present between the dorsal fins. Ventral surface without dermal denticles except for around snout and anterior disk margin.


Medium to dark brown dorsally with numerous small spots and blotches. The ventral surface is dark gray to black. Ampullar pores darkened ventrally; pale dorsally.


Maximum size to 57cm TL.


Demersal from 55-384m.


Known only from the northern Gulf of Mexico.


Compagno, L.J.V. 2002. Sharks. In: Carpenter, K.E. (Editor) FAO Identification Guide for Fishery Purposes. The Living Marine Resources of The Western Central Atlantic. Volume 1: Introduction, mollusks, crustaceans, hagfishes, sharks, batoid fishes, and chimaeras. ASIH Special Publication No. 5. FAO, Rome.

McEachran, J.D. and J.D. Fechhelm. 1998. Fishes of the Gulf of Mexico. Volume 1: Myxiniformes to Gasterosteiformes. University of Texas Press, Austin. i-viii + 1-1112.