W. A. Rogers

Human chorionic gonadotropin (HCG) is often used to induce spawning offish. However, the U.S. Food and Drug Administration has not approved HCG for use in fish because they claim additional efficacy data are required. Efficacy of HCG for spawning striped bass (Morone saxatilis) and white bass (M. chrysops) was evaluated at 15 hatcheries in 10 states. For strip spawning of females, a single dose of HCG was effective for 90.2% of striped bass (N = 428) and 89.4% of white bass (N = 660). After strip spawning, hatching rates were 39.5% for striped bass and 26.1% for white bass. Of 90 striped...

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...

In a food-habits study of young largemouth bass at the National Fish Hatchery, Marion, Alabama, midges were found to comprise 80 to 90 percent of the total food volume in fish from 25 to 55 millimeters in length. Since midges were found to be such an abundant food item in the diet of these fish, attempts were made to increase the midge crop by providing additional surface area in the pond for attachment. It was found that ponds having a dominant blue-green algae bloom (Anacystis spp. and Anabaena spp.) produced more midges than ponds having a dominant green algae bloom (Oocystis spp.,...