Longnose Eagle Ray, Myliobatis longirostris
The Longnose Eagle Ray, Myliobatis longirostris, whose common Spanish name is águila picuda, is a species in the Eagle Ray or Myliobatidae Family, known collectively as águilas marinas in Mexico. This fish is also known as the Snouted Eagle Ray. Globally, there are eleven species in the genus Myliobatis, five of which are found in Mexican waters, one in the Atlantic, three in the Pacific, and one in both oceans.
The Longnose Eagle Rays have flattened rhomboidal disc-shaped bodies that are approximately 1.75 times wider than they are long. They are dark reddish brown dorsally and their undersides are dusky white with gradual to dark edges. Their head is large, bulbous, elevated, and protruding with a long pointed snout. Their head and eyes are behind the origin of the pectoral fins; these fins are long and form equivalent triangles with pointed tips and concave rear edges. Their mouth has flat, pavement-like plates of teeth arranged in seven series. They have a single dorsal fin at the base of their slender whip-like tail, which is approximately twice the length of the disc and contains a long venomous spine with an injecting barb at the base used for self-defense. They have smooth skin without denticles.
The Longnose Eagle Rays are found inshore over sandy bottoms at depths up to 210 feet. They reach a maximum disc width of 97 cm (38 inches). Reproduction occurs via ovoviviparity with internal fertilization. Embryos are initially fed on yolk then receive additional nourishment from the mother by indirect adsorption of uterine fluid enriched with mucus, fat, and protein. Litter and pup sizes are unknown. They are an exceedingly rare and poorly studied species with very limited information available about their lifestyle and behavioral patterns including specific details on catch, age, growth, longevity, movement patterns, diet, habitat use, reproduction, and range.
In Mexican waters the range of the Longnose Eagle Ray is poorly documented, however, they are believed to be found from Guerrero Negro southward along the central and southwest coasts of Baja and within the Sea of Cortez.
The Longnose Eagle Ray can be confused with the Bat Rat, Myliobatis californica (much shorter non-projecting head) and the Rough Eagle Ray, Pteromylaeus asperrimus (disc width greater than twice the disc length; striping on underside; longer snout).
The Longnose Eagle Rays are scarce and seldom caught by artisanal fishermen. They do show up occasionally as a bycatch of demersal shrimp trawls, longlines, and gill nets and are normally discarded with a high mortality rate. There is no commercial fishery for the Longnose Eagle Ray. From a conservation perspective they are currently considered “near threatened”. This assignment is based on infrequent catches by artisanal fishermen, the overall population decline of many myliobatid rays, and an intense and unregulated fishery. Note: Rays of the genus Myliobatis have tails with a venomous spine. Although the Longnose Eagle Rays are exceeding rare, they are potentially dangerous as they can inflict wounds with intense pain and slow recovery. Approximately 1,500 stings from stingrays are reported annually.
Longnose Eagle Ray, Myliobatis longirostris. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, July 2009. Disc width: 60 cm (24 inches) x 32 cm (13 inches). Tail: 80 cm (31 inches). Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.