Whitesnout Guitarfish, Pseudobatos leucorhynchus
Whitesnout Guitarfish, Pseudobatos leucorhynchus, Juvenile. Provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, August 2013. Length: 21 cm (8.3 inches). Note that the underside of the snout is dusky which we believe is one present in juveniles. Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.
Whitesnout Guitarfish, Pseudobatos leucorhynchus. Fish caught out of coastal waters La Bocana, Baja California Sur, October 2015. Length: 66 cm (2 feet 2 inches). Catch and photograph courtesy of Jeff Dawson, Joseph, Oregon.
The Whitesnout Guitarfish, Pseudobatos leucorhynchus, is a member of the Guitarfish or Rhinobatidae Family, and is known in Mexico as guitarra trompa blanca. There are eight global members of the Pseudobatos Genus, of which seven are found in Mexican waters, two in Atlantic and five in the Pacific Ocean.
The Whitesnout Guitarfish has a shark-like body and a large triangular head that tapers to a pointed blunt snout and incorporate the fused pectoral fins. Their discs are longer than they are wide. They are dark gray-brown in color with a few scattered spots on their back. Their snout is translucent and has a dark tip. Their ventral side is off-white. Their snout is moderately long with a blunt point and their mouth is straight with long oblique nostrils. Their snout has 2 cartilaginous ridges that are fairly wide apart and converge at the front. They have a small spiracle behind each eye, with 2 folds in the rear border. Their body is smooth to the touch, with a series of small spines along the middle of their back, a single group on each shoulder, and a few above each eye and around their spiracles. Their caudal fin is asymmetrical and without a distinct lower lobe. They have 2 large triangular-shaped dorsal fins of equal size that originate behind their pectoral fins.
The Whitesnout Guitarfish is a demersal species that that is found in shallow coastal waters over sandy and muddy bottoms in bays and estuaries at depths up to 50 m (165 feet). They reach a maximum of 70 cm (2 feet 4 inches) in length and 3.2 kg (7 lbs 0 oz) in weight. They consume a wide variety of crustaceans and small fish. They are masters at camouflage and have the ability to rapidly change colors to match their substrate. Reproduction is via yolk sac with offspring born alive in litter sizes of 2 to 16 pups. The Whitesnouth Guitarfish 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.
The Whitesnout Guitarfish is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.
The Whitesnout Guitarfish is very similar in size and shape to several other Guitarfish but they are only one of two species that have a translucent or semi-translucent snout. The Speckled Guitarfish, Pseudobatos glaucostigma (slate gray spots on its head and upper body and parallel non-converging cartilaginous ridges on the snout), and the Shovelnose Guitarfish, Pseudobatos productus (darker snout).
From a conservation perspective the Whitesnouted Guitarfish and currently considered to be Near Threatened. They are heavily targeted by artisanal fishermen in all Mexican waters of the Pacific and also retained by bottom trawlers and gill net fishermen. Unregulated fisheries, their shallow water habitat and landing levels being unknown across their range all contribute to the concerns of the long term viability of this species. They are considered harmless to humans.