W. Clell Guest

A landlocked population of blueback herring (Alosa aestivalis) was established in 1982 in Lake Theo, Texas, and persisted for 7 years. Analysis of scales provided inaccurate ages for fish older than age 1. Analysis of otoliths provided valid ages of blueback herring, but protracted formation of annuli on otoliths limited the use of otoliths for back-calculating lengths of these fish. Fish in this landlocked population attained maximum total lengths of 240 mm, lived 2 years, and spawned only once. The disappearance of blueback herring in Lake Theo was attributed to their short life cycle...

The growth and reproductive cycle of a landlocked population of blueback herring (Alosa aestivalis) were evaluated in Lake Theo, a North Texas reservoir. Scales were collected and length, weight, and gonad characteristics were recorded for individual herring. Herring reproduced each year of the study. Average size of Age I herring ranged from approximately 70 to 170 mm total length (TL). Average size of Age II herring was approximately 200 mm TL and maximum size was 237 mm TL. Scale annuli formation in immature fish began in April; spawning marks occurred on scales in late summer. Herring...

Survival, growth, reproductive potential, and catchability of parental, F1 hybrid, and trihybrid sunfishes were evaluated in hatchery ponds for 28 months. The longear sunfish o x redbreast sunfish o F1 hybrid, its reciprocal, and these F1 hybrids outcrossed with the reader sunfish (i.e., trihybrids) were produced artificially, but natural hybridization in ponds was erratic. Survival of all fish types was good, and growth of F1 hybrids and trihybrids was greater than that of parentals. Only 1 F1 hybrid (redbreast sunfish o x longear sunfish o) exhibited a reduced reproductive potential. F1...

Adult Florida (Micropterus salmoides floridanus) and northern (M. s. salmoides) largemouth bass were subjected in the laboratory to low water temperature regimes similar to those occurring on Texas hatcheries. Northern largemouth bass survived all temperature regimes experienced. Florida largemouth bass suffered mortality that increased as temperature decline rate (1, 2, and 4 C/ day) increased. They survived prolonged exposure (30 days) at 4 C well, but total mortality occurred at 3 and 2 C. Northern largemouth bass were more tolerant than Florida largemouth bass of rapid temperature...