Featured Elasmobranch – Cortez Stingray

  • -

Featured Elasmobranch – Cortez Stingray

Photo Copyright: Amezuca Linares

Cortez Stingray

Urobatis maculatus (Garman, 1913)

Family Urotrygonidae

 

Identification: Disc circular shape, with tail length equal to or slightly less than disc length, a long venomous spine originating at mid-tail on the dorsal side; snout angular, dorsal fins absent, and a well-developed caudal fin. Skin smooth. Dorsal color varies from brown to brownish grey; dark spots and blotches cover the upper side of this ray; these blotches and spots are irregular, variable, and spread out; ventral surface lighter to whitish.

 

Size:  Maximum size is 25.7 cm disc width and 42 cm total length.  Size at maturity and at birth is unknown.

 

Distribution: The known range of this species is limited to the Gulf of California.

 

Habitat:   Occurs in benthic coastal waters, near sheltered areas around islands, bays, lagoons, and estuaries. They are found in depths ranging from 2 to 20 meters.

 

Biology: Little is known about the biology of this species but it has been speculated that it exhibits viviparity with yolk-sac placenta, similar to U. concentricus and U. halleri.  It is believed that the gestation period lasts 3 months with litters of 3 to 6 pups.  It feeds on bottom dwelling invertebrates such as crustaceans, mollusks, worms, and small fish. The spots and blotches on the dorsal side of are used for camouflage, allowing it to ambush prey and hide from predators.

 

General Interest:  The Cortez stingray is likely caught as bycatch, although the extent is unknown since commercial fisheries in Mexico do not typically utilize these rays. This species may be at risk due to its limited range, but management is difficult due to the lack of species information and confusion with U. concentricus and U. Halleri.  Conservation status is listed as data deficient.

 

The taxonomy on this ray is currently being investigated due to its similarities to Urobatis concentricus (Bullseye Round Stingray), and U. halleri (Round Stingray). However, the blotches can be used to distinguish U maculatus from U. halleri.

 

Justin Cordova

CSU Monterey Bay