Andrew J. Gingerich

Physiology, Behavior, and Survival of Angled and Air-Exposed Largemouth Bass

Abstract Catch-and-release practices are common in recreational fisheries, yet little is known about the behavior, physiology, and ultimate fate of released fish. We used a combination of radiotelemetry (external attachment) and nonlethal blood sampling (i.e., the blood concentrations of lactate and glucose and plasma concentrations of aspartate aminotransferase (AST), Na+, K+, and Cl−) to assess the relationship between the prerelease physiological status and postrelease behavior and mortality of largemouth bass Micropterus salmoides. The experiments were conducted at two temperatures: approximately 15°C and 21°C. Immediately after capture by standard angling techniques, largemouth bass were exposed to air for 0 to 15 min to assess the consequences of air exposure at two moderate water temperatures. Fish exposed to air for long periods (approximately 10 min or more) had significantly higher concentrations of blood glucose 30 min after air exposure and took significantly longer to regain equilibrium than ...

Contrasting Global Game Fish and Non-Game Fish Species

ABSTRACT: We compared biological and ecological traits between global game fish and non-game fish species using an analysis with randomly chosen fish species from each group and an analysis where species were matched by body length. We used data from the International Game Fish Association (IGFA), FishBase, and the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Game fish species were defined as being present in the IGFA world record list. The random comparison revealed that on average game fish were significantly larger (155.0 ± 121.5 versus 34.1± 59.5 cm), occupied shallower minimum depths (19.4 ± 58.8 versus 130.0± 359.0 m), had a broader latitudinal range (51°.2 ± 29.4° versus 31.1°± 25.9°), and significantly higher trophic levels (4.1 ±0.1 versus 3.4± 0.1 trophic units) than non-game fish species. The length-matched analysis simuarly identified that game fish species occupied higher trophic levels than non-game fish (3.9 ± 0.4 versus 3.6± 0.6 trophic units), but ...

The role of progeny quality and male size in the nesting success of smallmouth bass: integrating field and laboratory studies

Smallmouth bass display size-specific variation in reproductive success with larger brood-guarding males in a population more likely to rear offspring to independence than smaller individuals. The exact mechanisms responsible for this size-specific increase in reproductive output have yet to be identified. To assist in this process, we investigated the relationship between the size of brood-guarding male smallmouth bass and offspring quality (in this case, egg physiology, egg morphology, egg size, hatching success and lab survival). Further, we examined how factors such as egg physiology, egg morphology and egg size influenced reproductive success in the wild and hatching success in a controlled laboratory environment. Nesting male smallmouth bass that successfully reared their offspring to independence spawned earliest in the nesting period were the largest individuals, and guarded eggs with greater concentrations of cortisol compared to males that abandoned their offspring prematurely. Offspring survival in the laboratory was not correlated with offspring survival in the wild, indicating that caution should be used interpreting studies that attempt to relate laboratory-derived survival metrics to the wild. Together, results demonstrate size-specific differences in offspring quality for nesting smallmouth bass, which are correlated with higher concentrations of cortisol in eggs. However, hatching success under laboratory conditions was dissimilar to nesting success in the field relative to cortisol concentrations.

The effects of temperature change on the hatching success and larval survival of largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu

In this study, the effects of abrupt temperature change on the hatching success and larval survival of eggs, yolk-sac larvae (YSL) and larvae above nest (LAN), for both largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu were quantified. Temperature had a significant effect on hatching success and time to 50% mortality, with large heat shocks causing accelerated mortality. The temperature changes shown to influence survival of all life stages, however, were beyond what is typically experienced in the wild. Micropterus salmoides had greater egg hatching success rates and increased survival rates at YSL and LAN stages, relative to M. dolomieu. Additionally, egg hatching success and survival of LAN varied across nests within the study. These findings suggest that temperature alone may not account for variations in year-class strength and may emphasize the need for protection of the nest-guarding male Micropterus spp. to ensure recruitment.