Longnose Skate, Beringraja rhina
Longnose Skate, Beringraja rhina, Male. Fish caught from coastal waters off Sitka, Alaska, May 2022. Length: 86 cm (2 feet 10 inches). Catch, photograph and identification courtesy of Chris Wheaton, Fullerton, California.
The Longnose Skate, Beringraja rhina, is a member of the Skate or Rajidae Family, that is known in Mexico as raya narigona. Globally, there are six species in the genus Beringraja (a new Genus created in 2012), of which five are found in Mexican waters of the Pacific Ocean.
The Longnose Skate is large in stature with a wide flattened kite-shaped granular disc that is 1.2X wider than it is long with an anterior margin that is strongly concave. They have a very long snout that is acutely pointed and small eyes. Their five gill slits and mouth, which is pointed downward and equipped with small teeth arranged in diagonal rows which each tooth being plate-like with a very small cusp, are on the ventral side. They have large spiracles located behind the eyes on the dorsal side. They do not have an anal fin, their caudal fin is a low fold with a fleshy lateral ridge on each side, their dorsal fins are small, broadly rounded, set well back on the tail, and well separated, their pectoral fins are triangular, broad, attached to the snout, and are incorporated with the body, and their pelvic fins are strongly notched with the anterior lobe being as long as the posterior lobe. They have short (ca. 66% of disc length), slender, tails that are depressed with broad lateral folds near the tip that have thorns staggered in multiple rows. They have a row of twenty sharp mid-dorsal spines that extend from the base of the tail to the space between the dorsal fins, one or two spines immediately behind the eyes, and a few discontinuous rows of spines around the inner edge of the eyes. There are thorns on the disc around the eyes and the alar and nuchal regions of the adult males. Dorsally the Longnose Skate is reddish-brown or grayish-brown and some have mottled indistinct darker spots and blotches. They have one small, distinctive black eyespot, each with a pale center and light ring, on each pectoral fin, and one eye-sized white spot posterior to the ocelli. Some fish have a light spot just behind the eyespot. Their snout is black and their bellies are grayish.
The Longnose Skate is a demersal species that is found at depths between 10 m (33 feet) and 1,295 m (4,250 feet), but normally between 200 m (660 feet) and 400 m (1,320 feet) over sand, mud, and mixed rock soft substrate. They reach a maximum of 2.04 m (6 feet 8 inches) in length with the females being much larger than the males. They swim via a graceful sweeping motion appearing to fly rather than swim through the water. They feed on small fishes and a wide variety of invertebrates including crustaceans, mollusks, and worms. In turn they are preyed upon by large bony fish, sea lions, sharks and whales. They utilize camouflage for protection, and they have the ability to bury themselves partially or completely in the substrate. Their tail thorns are considered to an important component of their defense mechanism to avoid predation. Their egg cases are consumed by snails and marine mammals.
The females reach maturity from 10 to 14 years and the males in 7 to 12 years. Reproduction is oviparous with internal fertilization. The egg (normally only one) develops over several months and is placed in a tough, permeable oblong 9.4 cm (3.7 inch) to 13.0 cm (5.1 inch) long by 5.7 cm (2.2 inch) to 7.7 cm (3.0 inch) wide capsules, that are known as Mermaid’s Purses, which have stiff pointed horns at the corners and are deposited in sandy or muddy flats. The embryo continues to develop with nourishment provided by the yolk and when the yolk is depleted in a few months they exit the case. The young hatch at lengths of 12 cm (4.7 inches) to 17 cm (6.7 inch) and appear as miniature adults. They have life spans of up to thirty years. The Longnose Skate is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction. They are considered to be harmless to humans.
In Mexican waters the Longnose Skate are found from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja and within the northern portions of the Sea of Cortez
The Longnose Skate is easily confused with the Big Skate, Behringraja binoculata (less pronounced snout; pectoral fin margins less concave, darker spots on the pectoral fins that do not have white centers), the California Skate, Behringraja inornate (rounded pectoral fin tips and found only in shallow water at depths less than 12 m (40 feet), and the Deepsea Skate, Bathyraja abyssicola (thicker snout, lacks orbital thorns).
From a conservation perspective the Longnose Skate is currently considered to be of Least Concern with stable, widely distributed populations. They are targeted by commercially fishermen, utilizing bottom trawls and longlines, and considered to be important commercially in the northern Sea of Cortez and sold to South Korea. In general, however, the flesh is not highly regarded for human consumption. They are slow maturing, slow growing and have low reproductive rates making them vulnerable to overfishing with noted reductions in landing rates in certain regions.