Nakedbelly Searobin, Bellator gymnostethus
The Nakedbelly Searobin, Bellator gymnostethus, whose common Spanish name is vaca enana, is a species in the Searobin or Triglidae Family, known collectively as rubios and vacas in Mexico. Globally, there are only eight species in the genus Bellator, six of which are found in Mexican waters, three in the Atlantic and three in the Pacific.
The Nakedbelly Searobins, named for their scaleless breast and belly, have rectangular block-like bodies that are mottled reddish brown in color with faint brown bars on their sides and white undersides. Their large square bony head is covered with many ridges and spines. They have a single spine just above the front of each eye (a key to identification – see picture below). Their anal, second dorsal, and pelvic fins are transparent. Their caudal fin is orange with a dark spot on the lower lobe and there is a prominent ocellus spot between the fourth and fifth dorsal spines. Their mouth is small and their jaw does not reach eye level. Their snout has a pair of prolonged snout plates that form a “scalloped” shovel-shaped extension on each side of their snout tip. They have two separated dorsal fins with 11 spines and eleven rays with the second spine being the longest (another key to identification). Their pectoral fins are short, but reach the anal fin origin, and have two or 3 detached rays at the bottom of the fin. Their body is covered with rough scales.
The Nakedbelly Searobins are found over and within sandy and muddy bottoms adjacent to reefs at depths between 100 and 650 feet. They reach a maximum length of 15.0 cm (5.9 inches). They are more active and feed at night; during the day they are found submerged in sand.
In Mexican waters the Nakedbelly Searobin are found from Guerrero Negro southward along the central and southwest coasts of Baja, in the southern 80% of the Sea of Cortez, and along the coast of the mainland south to Guatemala.
Due to their size and rarity, the Nakedbelly Searobins are of limited interest to most. They are a frequent by-catch of deepwater shrimp trawlers around the tip of Baja.