Cominate Sea Catfish, Occidentarius platypogon

Cominate Sea Catfish, Occidentarius platypogon. Fish caught from coastal waters off Puerto Vallarta, Jalisco, February 2023. Length: 15 cm (5.9 inches). Catch and photograph courtesy of Ben Cantrell, Peoria, Illinois.

Cominate Sea Catfish, Occidentarius platypogon. Fish caught from coastal waters off Puerto Vallarta, Jalisco, February 2023. Length: 16 cm (6.3 inches). Catch and photograph courtesy of Allyn Toth, Peoria, Illinois.

Cominate Sea Catfish, Occidentarius platypogon. Commercial fish courtesy of Soriana’s Mercado, San José del Cabo, Baja California Sur, April 2019. Length: 27 cm (11 inches).

Cominate Sea Catfish, Occidentarius platypogon. Fish caught within the coastal waters of Magdalena Bay, Baja California Sur, October 2017. Length: 30 cm (12 inches).

Cominate Sea Catfish, Occidentarius platypogon. Fish caught at night off the beach at Todos Santos, Baja California Sur, January 2019. Length: 32 cm (13 inches). Catch, photograph and identification  courtesy of Brad Murakami, Surrey, British Columbia, Canada.

The Cominate Sea Catfish, Occidentarius platypogon, is a member of the Sea Catfish or Aridae Family, and is known in Mexico as bagre cominate. Globally, this is only species in the genus Occidentarius, and it is found in Mexican waters of the Pacific Ocean.

The Cominate Sea Catfish has a robust flattened body. They are a grayish olive-brown on the back that transitions to silvery and then to white ventrally. The fins are dusky and the anal fin has a white border. The head has three pairs of barbels, large eyes, a broad mouth with thick lips that is equipped with two pairs of tooth patches on the roof of the mouth with the inner pair being smaller than the triangular shaped, back pointing outer pair, and 3 pairs of barbels. They have wide gill openings and do have 14 to 16 gill rakers but none on the rear surfaces of the first two arches. Their anal fin has 18 to 20 rays; their caudal fin is deeply forked; their dorsal fin has 1 spine that is long and thin with prominent granules on the front surface that is venomous, and 7 rays; the second dorsal (adipose) fin has a base that is one-half to two-thirds of the first dorsal fin; and, the pectoral fins have 1 serrated and venomous spine and 10 or 11 rays.

The Cominate Sea Catfish is found in coastal waters over sandy and mud bottoms at depths between 6 m (20 feet) and 130 m (330 feet). The reach a maximum of 50 cm (20 inches) in length. They feed on small fishes and benthic invertebrates including clams, crabs and mollusks and reside over coastal sandy and mud bottoms. The Cominate Sea Catfish 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 Cominate Sea Catfish is a resident of all Mexican waters of the Pacific with the exception that they are absent from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.

The Cominante Sea Catfish is a somewhat challenging identification and can be easily confused with the Bigbelly Sea Catfish, Cathorops dasycephalus (second dorsal fin base greater than first dorsal fin base, found only from Mazatlán, Sinaloa southward along the coast of the mainland to Guatemala, with a maximum of 29 cm in length), the Tete Sea Catfish, Arius seemanni (pelvic fins with white borders, found only in from the central Sea of Cortez south to Guatemala, maximum of 35 cm in length, and the Widehead Sea Catfish, Ariopsis guatemalensis (blue back, small eyes).

From a conservation perspective the Cominate Sea Catfish is currently considered to be of Least Concern with stable widely distributed populations. They are fished commercially with nets and purse seines, and sold fresh or salted commercially for human consumption, but not at a significant level. From a recreational angling perspective, they are considered to be a “hated trash fish.”