Channel Catfish, Ictalurus punctatus
The Channel Catfish, Ictalurus punctatus, whose common Spanish name is bagre de canal, is a member of the North American Catfish or Ictaluridae Family, known collectively as bagres de agua dulce in Mexico. This fish is also known as the Channel Cat. Globally, there are 51 species in the Ictaluridae Family, which have been placed in seven genera and include blue catfish, bullheads, channel catfish, and madtoms. The Ictaluridae Family is the largest freshwater family endemic to North America. There are 10 species in the genus Ictalurus, all of which are found in the freshwater systems of Mexico.
The Channel Catfish have elongated bodies that are compressed posteriorly. They are bluish olive, gray or black dorsally and transition to white ventrally. They have dark round spots randomly scattered along their sides. Juveniles are lighter in color than adults. They are dimorphic with males being swollen above the eyes and having black lips during the breeding season while the body and lips of females turn lighter in color. Their head is wide when viewed from above. They have small eyes and an inferior mouth with eight sensory barbels, four on the chin, two on the snout, and one on each corner of the mouth. Their anal fin has 24 to 27 rays and a rounded margin; their caudal fin is deeply forked; their dorsal fin has one stout venomous spine and six or seven rays followed by a small adipose fin; their pectoral fins have one stout venomous spine; and their pelvic fins are found on the abdomen. They have smooth skin and no scales.
The Channel Catfish are normally found in small streams and ponds with clean and well oxygenated water but are also known to enter larger bodies of water with temperatures between 10oC (50oF) and 32oC (90oF). They reach a maximum length of 1.32 meters (4 feet 4 inches) and weight of 26.3 kg (58 pounds). They are active nighttime predators and probe the bottom as scavengers seeking food by smell, sight, and touch. They feed on small fish, clams, crustaceans, snails, aquatic insects, and small marine mammals. Juveniles consume plankton and aquatic insect larvae. In turn they are preyed upon by various larger fish as well as birds. They are known to “hibernate” by burying themselves in the substrate during low oxygen and low temperature episodes. Reproduction is oviparous with each female placing between 2,000 and 70,000 eggs in a small hole or depression on the lake floor; these eggs are then fertilized and guarded by males. Males exclude females to avoid cannibalization of their eggs. The eggs hatch within a week and the young form schools that are guarded by males for a short period. They grow rapidly in the first year. Introduced Channel Catfish are known to hybridize with several native catfish and bullheads in Mexico, including with the Yaqui Catfish, Ictalurus pricei. They are scientifically interesting and have been studied extensively due to their keen sense of hearing, sight, and smell. They also have the ability to generate a wide variety of different drumming sounds, which are used as important communication methods and also as defense mechanisms. They release a specific individual pheromone that can be recognized by other Channel Catfish. They have been used as test subjects for determining chemical transfers, immune responses, and antibody formation in basic scientific research. They have a lifespan of up to 24 years.
In Mexican water the Channel Catfish are well known along the northern and northeast parts of the mainland in all freshwater systems of the Atlantic drainage. The fish photographed below documents the presence of this species within Baja California Sur and one can only surmise that it got there via introduction.
The Channel Catfish are a major commercial species caught either in baited slat traps or hoop traps or raised as farmed fish. They are considered an exceptional food fish and widely sold commercially. They are also a major target of recreational anglers as larger fish can be fierce foes by rod and reel. They are caught by a wide variety of methods on almost any bait as well as by a unique method known as “noodling” where fish are caught by hand. They have, however, developed a reputation for being nuisance fish due to their effective bait stealing abilities. From a conservation perspective they are considered of Least Concern being common throughout their range and having increasing populations. Introductions are widespread globally as both sportfish and food fish, however, they quickly become highly invasive and a nuisance fish. Introduced fish are known to consume, compete with, and contribute to the demise of the Colorado Pikeminnow, Ptychocheilus lucius, an endangered species, the Humpback Chub, Gila cypha, the Razorback Sucker, Xyrauchen texanus, the Trout-Perch, Percopsis omiscomaycus, and the Chiricahua Leopard Frog, Rana chiricahuensis. They are also raised in abundance via aquaculture. The albino form is sold by the aquarium trade.
Channel Catfish, Ictalurus punctatus. Fish caught via hook and line by Mauricio Correa from an irrigation pond in the greater Los Cabos area, Baja California Sur, February 2008. Length: 54 cm (21 inches). Catch courtesy of Mauricio Correa, Los Cabos, Baja California Sur. Fish identification by H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.