Effects of lunar cycles on the activity patterns and depth use of a temperate sport fish, the largemouth bass, Micropterus salmoides

Largemouth Bass Micropterus salmoides, Florida Bass M. floridanus, and their intergrade are socially and economically valuable sport fish. In the southeastern United States, it is customary to age black bass (Micropterus) spp. using sagittal otoliths which requires killing the fish. Presently, fisheries managers and black bass anglers show reluctance to sacrifice large individuals. Development of a nonlethal ageing technique would not only allay concerns of sacrificing large black bass, but it could offer a pathway for new research, management, and conservation. We excised dorsal spines III–V from Largemouth Bass in Florida varying from 30–57 cm total length to evaluate the effects of the procedure on survival over 35 days. No mortalities were observed for fish with excised dorsal spines, and experiment-wide survival was 0.94 (0.87–1.00; 95% confidence interval). No significant differences in survival, weight change, or incidence of external injuries were observed between control and excised fish. The areas of spine excision healed with no visible infection or inflammation at the conclusion of the experiment. Therefore, dorsal spine removal offers managers a nonlethal option for collecting ageing structures of adult Largemouth Bass in Florida, including large individuals, and this result likely extends to other Micropterus spp. as well.

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Black Bass Diversity: Multidisciplinary Science for Conservation

Black Bass Diversity: Multidisciplinary Science for Conservation ◽

10.47886/9781934874400.ch18 ◽

2015 ◽

Keyword(s):

Largemouth Bass ◽

Micropterus Salmoides ◽

The United States ◽

Environmental Drivers ◽

Minimum Length ◽

Catch And Release ◽

Black Bass ◽

Intensively Managed ◽

Catch Rates ◽

Sport Fish

Abstract.—Largemouth Bass (LMB) Micropterus salmoides is one of the most popular sport fish in the United States and is intensively managed across much of its range. Beginning in 1989, Wisconsin implemented more restrictive harvest regulations for LMB, including greater minimum length limits, reduced bag limits, and a catch-and-release-only season during the spawning period across much of northern Wisconsin. We tested for trends in LMB relative abundance, growth, and angler catch and harvest in relation to LMB management policies from 1990 to 2011. We also tested for potential sport fish community responses to changes in LMB abundances using Walleye (WAE) Sander vitreus as an example. Angler catch rates and electrofishing catch per unit effort of LMB greater than 8 and 14 in increased significantly statewide. Mean length of age-6 LMB decreased significantly statewide. Release rates of LMB increased from about 80% in 1991 and then plateaued at more than 96% from 2005 to 2011. Concurrent with increases in LMB, adult WAE densities declined in lakes containing LMB. Ongoing research is being conducted to test for interactions between LMB and WAE and to test for additional environmental drivers, such as climate warming, that may be associated with increased LMB abundances. Largemouth Bass abundances have increased in Wisconsin, possibly in response to changes in harvest regulations, angler behavior, and potentially other environmental drivers. These increases in LMB abundances have had negative intraspecific effects on growth and may be negatively affecting WAE stocks. We recommend that management goals for LMB consider intra- and interspecific consequences, particularly in water bodies where multispecies fisheries are desired.

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Are muscle fibers within fish myotomes activated synchronously? Patterns of recruitment within deep myomeric musculature during swimming in largemouth bass

Journal of Experimental Biology ◽

10.1242/jeb.198.3.805 ◽

1995 ◽

Vol 198 (3) ◽

pp. 805-815 ◽

Cited By ~ 18

Author(s):

B Jayne ◽

G Lauder

Keyword(s):

Largemouth Bass ◽

Muscle Activity ◽

Micropterus Salmoides ◽

Activity Patterns ◽

Three Dimensional ◽

Significant Heterogeneity ◽

X Rays ◽

Horizontal Septum ◽

Vertical Row ◽

Longitudinal Position

The myomeric axial musculature of fish has a complex three-dimensional morphology, yet within-myomere motor patterns have not been examined to determine whether all portions of each myomere are activated synchronously during locomotion. To gain insight into recruitment patterns in the deep myomeric musculature of fish, we implanted a series of fine-wire electrodes arranged in a vertical row of six electrodes and a longitudinal row of three electrodes on both the left and right sides of each of five largemouth bass (Micropterus salmoides). After recording electromyograms (EMGs) during the burst-and-glide swimming of each fish, post-mortem dissections and X-rays determined the location of electrodes with respect to (1) the longitudinal position (by counting the underlying vertebrae), (2) the position of the myomere containing the electrode, and (3) the portion within each myomere containing an electrode. Because of the convoluted overlapping shape of the myomeres, electrodes within the vertical row of sites could be located in any one of six different myomeres. Thus, we compared muscle activity for locations with a constant longitudinal position and differing myomeric position (vertical row) and among sites with both variable longitudinal and myomeric positions. We detected significant heterogeneity in EMG onset times for sites within the vertical row of electrodes; however, the durations of the EMGs from different sites were similar. EMG onset times at more posterior longitudinal positions preceded those of more anterior longitudinal positions when electrodes of the latter site were within a more posterior myomere. Thus, the timing of EMGs was consistent with the posterior propagation of muscle activity via the sequential activation of myomeres rather than the simultaneous activation of all contractile tissue within the longitudinal span of a single vertebra. In addition, extreme epaxial and hypaxial portions of myomeres showed distinct activity patterns which did not necessarily correlate with activity in the central myomeric fibers nearer the horizontal septum.

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