Rex A. Dunham

Ozark hellbenders (Cryptobranchus alleganiensis bishopi) are large aquatic salamanders found in flowing waters. The abundance of this species is thought to have declined over the long term. What had been the most abundant population, in Spring River, Arkansas, appears to have declined precipitously in the last decade. The possibility of supplementing the population through captive propagation has been suggested, raising concerns about genetic issues. Random amplified polymorphic DNA (RAPD) was evaluated for assessing genetic variability among and within populations of Ozark hellbenders...

Twenty-eight populations of brook trout (Salvelinus fontinalis) in Georgia were genetically compared using isozymes and their genetic relatedness determined. Eight populations (29%) were classified as southern based on fixation for CK-A2*122 allele, 2 (7%) populations were classified as northern based on fixation for CK-A2*100 allele, and the remaining 18 (64%) were northern-southern hybrid populations. All 8 southern populations shared some variant alleles with northern populations. Northern brook trout in Georgia had much greater genetic variation than southern brook trout, and hybrid...

Striped bass (Marone saxatilis) from the Apalachicola River, Florida; Chattahoochee-Flint River, Georgia; Ogeechee River, Georgia; Savannah River, Georgia; Santee-Cooper River, South Carolina; Tallapoosa River, Alabama; and Chesapeake Bay, Maryland, were examined for polymorphism in their mitochondrial DNA (mtDNA) genotype. The Xba I site loss that is supposed to identify individuals with matemallineage from Gulf Coast stocks was found in some fish from the Apalachicola and Chattahoochee-Flint rivers, as well as one individual from the Ogeechee River. Additionally, a unique Bgl I site gain...

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...

Two populations of channel catfish (lctalurus punctatus) with different histories of domestication-Marion (Alabama) and Kansas-were grown in earthen ponds at 7,500/ha. The largest 10% of each population were selected when population mean weights were 500 g. The reproductive performance of these selects was compared to that of brood from random control populations. Data were analyzed for each strain then pooled and re-analyzed. No differences were found in spawning day, spawning rate, hatchability of eggs and survival of sac fry. Fecundity (eggs deposited) was increased (P < 0.05) in the...