Equatorial Skate, Raya equatorialis: The Equatorial Skate has a light brown back and a white underside; the edges of the disk are pale.
The snout and spines are translucent. The body of this fish species consists of a large flattened rhomboidal disk with a pointed head and pointed “wings.”
The head of the Equatorial Skate has large spiracles behind the eyes, a rigid snout. The front edge of the disk is straight to convex.
This fish species has two dorsal fins at the rear of the tail and no caudal fin. The width and length of the disk are the same and the tail is approximately 57 percent of the length of the disk. The pelvic fins have two distinct lobes with the rear one being large.
The disk is covered with small, thin, ungrooved oval based spines. There is one row of thorns from the nape of the neck along the back of the disk to the tail, another row on each side along the tail, a row inside and before the eye, and for or five short rows of thorns on the edges of the disk opposite the eyes.
The Equatorial Skate can be confused with a series of other skates. However only two others have the large pair pelvic fins: the California Skate, Raja inornata (one row of tail thorns, no thorns on edges of pectoral fins); and the Rasptail Skate, Raya velezi (large thorns on tail; two ocelli spots on back).
It is found between 60 and 600 feet deep in the water column over sandy bottoms. It reaches a maximum length of just under 3 feet.
In Mexican waters the Equatorial Skate is found south of Guerrero Negro, along the Pacific side of Baja California, in the lower 70 percent of the Sea of Cortez, and along the Mexican mainland coast south to Guatemala.
It is a member of the Rajidae Family which includes fanskates and skates, known in Mexico as rayas.
There are 200 members of the family with 18 genera of which 32 species are of the Raja Genus with 5 species frequenting Mexican fishing waters. They all have a large flattened rhomboidal disk that consists of head, body and pectoral fins. The eyes are on top of the head with spiracles immediately behind. The nostrils are a little in front of the mouth (found on the underside) and the lobes from the nostrils form a curtain between them and the mouth. They have slender tails, which are well demarcated from the body, less then twice as long as the length of the disk. They have two small dorsal fins near the rear of the tail with the caudal fin existing as a fold behind the second dorsal fin. The pelvic fins have two lobes that are separated by a notch. The upper surface of the body is covered with prickles and there are rows of thorns along the mid-line.