Yellow Bobo, Polydactylus opercularis
The Yellow Bobo, Polydactylus opercularis, whose common Spanish name is barbudo nueve barbas, is a member of the Threadfin or Polynemidae Family, known collectively as barbudos in Mexico. Globally, there are twenty species in the genus Polydactylus, five of which are found in Mexican waters, three in the Atlantic and two in the Pacific.
The Yellow Bobos have elongated compressed bodies and are fairly similar to freshwater catfish. They are bronzy brownish dorsally and transition to silvery yellow ventrally. They have a large dark blotch on their gill cover. Their pectoral fins are bright yellow and their other fins are yellowish. Their head has a short conical snout that overhangs the mouth, large eyes with fatty covers that are well forward, and a modest sized mouth below the snout equipped with teeth in bands on the top jaw. Their anal fin has a short base with 3 spines and 13 to 15 rays. Their caudal fin is deeply forked. They have two well-separated dorsal fins, the first with 7 spines and the second with one spine and 12 or 13 rays. Their pectoral fins are low on the sides and divided in two parts: the first is low and under the gills with 6 to 9 long free rays and the second is in the upper section with 14 to 16 rays. Their free pectoral rays serve as feelers and scoops in the feeding process. Their pelvic fins are far behind the pectoral fins and slightly preceding the second dorsal fin. They have 31 to 37 gill rakers. Their lateral line extends into the caudal fin branching into each lobe. Their body is covered with rough scales.
The Yellow Bobos are a non-migratory species found over sandy and muddy bottoms in bays, estuaries, and river mouths, and along sandy beaches at depths up to 350 feet. They reach a maximum length of 50 cm (20 inches). They feed on mobile benthic invertebrates. The Yellow Bobos are poorly studied and very little is known about their behavioral patterns.
In Mexican waters the Yellow Bobos are found in all waters of the Pacific with the exception of the extreme northern portions of the Sea of Cortez.
The Yellow Bobo is easily confused with the Blue Bobo, Polydactylus approximans (blue-white coloration; 5 or 6 free pectoral rays; black pectoral fin).
The Yellow Bobos are relatively small, not abundant, and of limited interest to most. However, when available they are considered an excellent food fish. From a conservation perspective they are widespread with abundant populations in certain locations and are currently classified as of Least Concern.
Yellow Bobo, Polydactylus opercularis. Fish caught off the beach at Punta Lobos, Baja California Sur, May 2006. Length: 30 cm (12 inches).