Hemoglobin patterns were identified by electrophoresis for channel catfish, Ictalurus punctatus; blue catfish, I. furcatus; white catfish, I. catus; brown bullhead, I. nebulosus; and (female x male) blue x channel, channel x blue, white x blue and channel x white hybrids. Hemoglobin patterns of each species were different with channel catfish having 11 bands; blue catfish, 8; white catfish, 5; and brown bullheads having 3 different patterns of 6, 10, and 11 bands. All hybrids except channel x white (10 bands) had 11 bands. The banding pattern exhibited by the hybrids was a combination of the parental pattern except for 1 or 2 hemoglobins unique to the hybrids. Total hemoglobin and hematocrit were higher for channel catfish and brown bullheads than blue catfish and white catfish. Maternal effects were evident for total hemoglobin in crossbred channel catfish and channel-blue hybrids. White x blue hybrids exhibited overdominance for total hemoglobin and hematocrit. The molecular weight of channel catfish hemoglobin was estimated to be 67,000 when compared to known compounds.
