Clearnose Skate

Clearnose Skate, Raja eglanteria

The Clearnose Skate, Raja eglanteria, whose common Spanish name is raya naricita, is a member of the Skate or Rajidae Family, known collectively as rayas in Mexico. Globally, there are thirty-two species in the genus Raja, eight of which are found in Mexican waters, three in the Atlantic and five in the Pacific.

The Clearnose Skates are diamond-shaped with their snout and pectoral fins forming a flattened disc that includes the head, body, and pectoral fins. The front edge of their disc can be straight or convex and their snout and pectoral fins are at a right angle. They have a pointed head and pointed “wings”. They are light brown to gray with darker spots and bars dorsally and transition to white ventrally. Their snout is translucent after which they are named. They have a series of small dark spots and bars on their back. They have a rigid pointed snout and large spiracles behind their eyes. They have small blunt teeth that are set close together with 46 to 54 teeth on their upper jaw and 48 teeth on their lower jaw. Their disc is slightly wider than it is long and their tail is 57% of disc length. They have two dorsal fins at the base of their tail and no caudal fin. Their pelvic fins have two distinct lobes with the rear lobe being the largest. Their disc is covered with small thin oval spines. They have one row of thorns that run from the nape of their neck along the back to the tail, another row on each side of their tail, a row inside and before their eyes, and four or five short rows on the edges of their disc opposite the eyes.

The Clearnose Skate are found demersal along shallow waters of the continental shelf over soft substrate like mud and sand or on harder surfaces like rock and gravel at depths up to 1,000 feet. They have a maximum disc width of 48 cm (19 inches) and length of 84 cm (33 inches) and their tail is approximately half the disc length. They can be found in water temperatures between 6.3oC (43oF) and 27oC (81oF). They are known to make seasonal northward migrations moving to cooler waters during the summer months and returning south in the fall and winter. During cold water episodes they are also known to move to deeper waters. They are sexually dimorphic with males having sharper teeth than females. They are nighttime predators consuming crabs, mollusks, shrimp, and small fish. In turn they are preyed upon by various larger sharks. Reproduction is oviparous with females being able to store sperm for at least three months. Large fertilized eggs are laid in black or dark green leathery shells, known as mermaid’s purses, that have an oblong outline with a hollow tendril at each corner, which is used to attach to marine objects; these are deposited in sandy and muddy flats that are approximately 7.0 cm (2.8 inches) long and 4.2 cm (1.6 inches) wide. They are produced in pairs with each case containing up to seven embryos and each female producing up to 66 eggs per year. The embryos emerge in approximately 12 weeks as miniature adults that are 13.0 cm (5.1 inches) to 15.0 cm (5.9 inches) in total length with disc widths of 8.4 cm (3.3 inches) to 10.5 cm (4.1 inches). They have a lifespan in excess of five years. They are fairly rare with a limited distribution and very little is known about their behavioral patterns.

In Mexican waters the Clearnose Skates have a limited distribution being found only in the western portions of the Gulf of Mexico.

The Clearnose Skate is similar in shape to the Gulf Skate, Fenestraja sinusmexicanus, the Roundel Skate, Raja texana, and the Spreadfin Skate, Dipturus olseni, but the snout of all three is solid in color and similar to the dorsal body coloration.

The Clearnose Skates are a frequent catch of recreational anglers but deemed to be of limited value. They are not targeted commercially due to their small size but are caught with some frequency by otter trawls. They are not considered excessively dangerous to humans. They lack the venomous spines found in stingrays, however the thorns on their back can be truly lethal. They adapt well to captivity and have become a popular component of large public aquariums. From a conservation perspective they are currently considered of Least Concern with stable populations, however, catch levels and population trends are not monitored.

Clearnose Skate (1)Clearnose Skate, Raja eglanteria. Fish caught from coastal waters off Tampa, Florida, December 2013. Disc width: 32 cm (13 inches); disc length: 30 cm (12 inches); tail: 17.0 cm (6.7 inches). Catch, photo, and identification courtesy of Ben Cantrell, Peoria, IL.