Effects of Reservoir Hydrology on Reproduction by Largemouth Bass and Spotted Bass in Normandy Reservoir, Tennessee

Abstract.—Following reports of invasive Spotted Bass Micropterus punctulatus in the Chipola River, Florida, we initiated a microsatellite DNA survey of black basses in that system to assess genetic risks to the native population of Shoal Bass M. cataractae. Nonnative Spotted Bass and naturally occurring Largemouth Bass M. salmoides × Florida Bass M. floridanus intergrades were sampled from the Apalachicola and lower Chipola rivers to serve as reference specimens. In 2007, we identified five Shoal Bass hybrids among 45 specimens of Micropterus. Two of the hybrid specimens had introgressant alleles from Spotted Bass and another two had introgressant alleles from Largemouth Bass × Florida Bass intergrades. The introgressing taxon for the remaining hybrid was not immediately identifiable and was later determined to be an undescribed species of Micropterus (provisionally named Choctaw Bass), which inhabits the coastal plain rivers of the eastern Gulf of Mexico. From 2008 to 2010, an additional 217 specimens from the system were genotyped, resulting in the identification of 36 hybrids. Overall, 15.9% of the unknown specimens were heterospecific; the overall genomic proportion of introgressant alleles was 4.0%. The largest fraction of introgressant alleles (3.0%) originated from Choctaw Bass, most likely carried by emigrants from the nearby Choctawhatchee River system. Largemouth Bass × Florida Bass intergrades contributed the next highest introgressant proportion (0.6%), followed by Spotted Bass (0.4%). One genetically pure Spotted Bass was detected among the upper Chipola River specimens. Point estimates of genetic effective size for the Chipola River Shoal Bass population ranged from 110.4 to 131.4 (95% confidence interval [CI] = 79.1 to 195.9); values of this magnitude could signal an increased susceptibility to hybrid-swarm formation and reduced efficacy of purifying selection. While this population harbors a nontrivial amount of introgressant alleles, the majority of interbreeding appears to originate via natural processes. Nonetheless, if nonnative Spotted Bass become further established in the Chipola River and increase their interactions with Shoal Bass, the genetic integrity of the endemic population could deteriorate rapidly.

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Influence of Trophic State on Spotted Bass and Largemouth Bass Spawning Time and Age-0 Population Characteristics in Alabama Reservoirs

North American Journal of Fisheries Management ◽

10.1577/1548-8675(2000)020<0100:iotsos>2.0.co;2 ◽

2000 ◽

Vol 20 (1) ◽

pp. 100-108 ◽

Cited By ~ 5

Author(s):

James C. Greene ◽

Michael J. Maceina

Keyword(s):

Largemouth Bass ◽

Trophic State ◽

Population Characteristics ◽

Spawning Time ◽

Spotted Bass

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Managing Centrarchid Fisheries in Rivers and Streams

Managing Centrarchid Fisheries in Rivers and Streams ◽

10.47886/9781934874523.ch8 ◽

2019 ◽

Keyword(s):

Largemouth Bass ◽

Habitat Associations ◽

Habitat Partitioning ◽

Habitat Alteration ◽

Wet Prairie ◽

Rivers And Streams ◽

Distributional Patterns ◽

Wadeable Streams ◽

Spotted Bass ◽

Species Specific

Abstract.—Historic reports and museum records describe a distinct spatial distribution pattern and habitat partitioning between Largemouth Bass Micropertus salmoides salmoides and Spotted Bass Micropterus punctulatus. However, beginning in the mid-20th Century, the literature describes more co-occurrences and less species specificity among habitats and distributions. Herein, we conducted a retrospective analysis of recently collected data (2005–2014) to assess: (1) how current distributional patterns of Spotted Bass and Largemouth Bass compare with historic distributions in Louisiana; (2) evidence of species-specific habitat associations based on abundance and habitat data collected; and (3) whether the Florida Largemouth Bass M. salmoides floridanus stocking program has affected Spotted Bass populations in adjacent river systems. Analyses of 68 wadeable streams and rivers indicated that current spatial distributions matched historic descriptions for 6 of 9 major drainages, with evidence still supporting distinct habitat associations for each species. Importantly, Spotted Bass did appear to be negatively influenced by widespread Largemouth Bass stocking. Further, construction of reservoirs across the state and landscape conversion from wet prairie and forest to intensive agriculture may have negatively impacted both species. Overall, habitat alteration and loss was the most widespread explanation for declines in Spotted Bass, with Largemouth Bass stocking of secondary and more localized importance.

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Managing Centrarchid Fisheries in Rivers and Streams

Managing Centrarchid Fisheries in Rivers and Streams ◽

10.47886/9781934874523.ch14 ◽

2019 ◽

Keyword(s):

Life History ◽

Relative Abundance ◽

Largemouth Bass ◽

Rivers And Streams ◽

Major Tributary ◽

Black Bass ◽

Spotted Bass ◽

Coastal River ◽

Choctawhatchee River ◽

Regulation Changes

Abstract.—The Choctaw Bass Micropterus cf. punctulatus is an undescribed black bass found in coastal river systems of northwest Florida and southern Alabama. The Choctaw Bass is morphologically similar to the Spotted Bass M. punctulatus. Prior to this study, there was no published life history information specific to this black bass. The need to address these information gaps was further influenced by the popularity of black bass fishing and potential statewide black bass regulation changes in Florida. Our research examined relative abundance, age, mortality, growth, and diet of Choctaw Bass collected from the Choctawhatchee River, Florida and Holmes Creek, a major tributary of the Choctawhatchee River in fall 2012 and 2013. Choctaw Bass were compared to sympatric Largemouth Bass M. salmoides × Florida Bass M. floridanus intergrades. Relative abundance was lower for Choctaw Bass than Largemouth Bass in both the Choctawhatchee River and Holmes Creek. The oldest Choctaw Bass from the Choctawhatchee River was age-5 and the oldest Choctaw Bass from Holmes Creek was age-11. Total instantaneous mortality of Choctaw Bass was statistically similar between the study areas. Total instantaneous mortality for Choctaw Bass from Holmes Creek was also similar to sympatric Largemouth Bass. Growth differed for Choctawhatchee River and Holmes Creek Choctaw Bass. Diets of Choctaw Bass collected from the Choctawhatchee River consisted primarily of fish while diets of Choctaw Bass and Largemouth Bass collected from Holmes Creek consisted primarily of crayfish. The observed restricted distribution, limited abundance relative to Largemouth Bass, limited number of Choctaw Bass collected greater than 406 mm TL, and the lack of Choctaw Bass older than age-5 in the Choctawhatchee River led to the recommendation that Choctaw Bass be managed separately from Largemouth Bass.

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