Featured Elasmobranch – Equatorial Skate
Category : Featured Elasmobranch
Photo Copyright: Phillippe Bearez
Raja equatorialis (Jordan and Bollman, 1890)
Identification: Disc width one-third greater than length; width is greater than tail length. Snout produced at an acute angle with rounded tip. Interorbital space is highly concave. Eye diameter about equal to spiracle length. Pectoral fins extend to middle of pelvic fins, which are as long as tip of snout to posterior side of spiracles. The Equatorial skate is similar in appearance to the California skate (Raja inornata); however, it can be distinguished by having four rows of thorns below the eyes and a series of thick thorns on either side of the tail in adult males. The Equatorial skate has a median series of prickles and a spine on each shoulder of dorsal surface, but otherwise is smooth. No markings are present on the underside of this skate. Coloration is light brown with an obscure round dusky blotch at the middle of the base of the pectoral fins and a darker blotch near the posterior base. The edges of its pelvic and pectoral fins and snout are pale. Dark markings are present on the interorbital area and below the eye.
Size: Maximum total length (TL) recorded was 88 cm (2.88 ft). Length at maturity is currently unknown.
Distribution: The Equatorial Skate occurs along the central Eastern Pacific coast from the Gulf of California to Peru as well as the Galapagos Islands.
Habitat: This tropical skate species occurs on the continental shelf on the central Eastern Pacific Ocean. There is much to be learned still about specific habitat associations. Current depth range for this species has been recorded as 3 to 200 meters. The maximum depth limit for this species is unknown.
Biology: The Equatorial Skate is oviparous and its eggs have ‘horn-like’ projections on the shell. Nothing else is known about its biology.
General Interest: This species has been listed as Data Deficient on the IUCN Red List. It is likely caught as bycatch in demersal fisheries in the central Eastern Pacific. The shrimp trawl fleet, in particular, fishes heavily inside the Equatorial Skate’s range along the continental shelf. Very little is currently known about the life history aspects of this species, making management and conservation difficult.
By: Ryan T. Fields
Fisheries Conservation and Biology Lab
Moss Landing Marine Laboratories