scholarly journals Evidence Dorsal Spine Removal is Nonlethal and Unharmful for Largemouth Bass in Florida

Author(s):  
Summer Lindelien ◽  
Andrew C. Dutterer ◽  
Paul Schueller ◽  
Chris C. Anderson

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.

<em>Abstract</em>.—Largemouth Bass (LMB) <em>Micropterus salmoides</em> 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) <em>Sander vitreus</em> 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.


2018 ◽  
Vol 94 ◽  
Author(s):  
M. García-Varela ◽  
C.D. Pinacho-Pinacho

AbstractMembers of the genusNeoechinorhynchusStiles & Hassall, 1905 are endoparasites of freshwater fishes, brackish water fishes, and freshwater turtles distributed worldwide. In North America, 33 species have been described. One of the most widely distributed species in the eastern United States and Canada isNeoechinorhynchus (Neoechinorhynchus) cylindratus,a common acanthocephalan that infects centrarchid fishes. In the current study, adult specimens ofN. (N) cylindratuswere collected from largemouth bass (Micropterus salmoides) from the Purificación River in northern Mexico. In the same freshwater system, two additional congeneric species (Neoechinorhynchus (Neoechinorhynchus) emyditoidesandNeoechinorhynchus (Neoechinorhynchus) panucensis) were collected and analysed. Sequences of the large subunit, internal transcribed spacers ITS1 and ITS2, 5.8S from nuclear DNA, and sequences of the cytochromecoxidase subunit I (cox1) from mitochondrial DNA were generated and aligned with other sequences obtained from GenBank. Maximum likelihood and Bayesian inference analyses inferred for each dataset showed thatN. (N) panucensis,N. (N) emyditoidesandN. (N) cylindratuswere nested within several clades, indicating that these species do not share a common ancestor. Our phylogenies also revealed that the genusNeoechinorhynchusis paraphyletic, requiring further taxonomic revision using phylogenetic systematics and re-examination of morphological and ecological data. The presence of severalN. (N) cylindratusadults in northern Mexico allowed us to typify this species for the first time using a combination of morphological and molecular characteristics. The current record shows a wide distribution range ofN. (N) cylindratusacross Canada, the United States and Mexico in the Nearctic region.


<em>Abstract</em>.—Thirteen United States fishery agencies utilized routine supplemental stocking as a means to manage largemouth bass <em>Micropterus salmoides </em>populations in large (>405-ha) reservoirs. State agencies stocking largemouth bass used two strains (i.e., northern and Florida) as well as intergrades. Largemouth bass for stocking were raised in hatcheries, lakeside nursery ponds, or both. Among states, methods used to monitor fish in hatchery ponds and lakeside nursery ponds, the date ponds were drained, and methods to enumerate fish from the ponds varied. Although most states cited bolstering weak year-classes as their main reason for routine stocking, others noted increasing genetic variability within populations and public pressure as reasons that their agencies stocked large reservoirs with largemouth bass. As agencies continue to respond to public pressures for larger fish, they should consider the possible consequences of mixing stocks of largemouth bass. With continued development of agency rearing techniques, especially in lakeside nursery ponds, methods to enumerate fish should be considered to aid in future stocking evaluations. Improved rearing and stocking techniques will allow fisheries managers to utilize resource dollars in a way that provides benefit to anglers while ensuring the sustainability of largemouth bass populations.


2008 ◽  
Vol 15 (5-6) ◽  
pp. 357-364 ◽  
Author(s):  
K. C. HANSON ◽  
S. ARROSA ◽  
C. T. HASLER ◽  
C. D. SUSKI ◽  
D. P. PHILIPP ◽  
...  

<em>Abstract.</em>—Largemouth Bass <em>Micropterus salmoides</em> is typically thought of as a freshwater species, but populations occur in oligohaline portions of estuaries throughout the U.S. Atlantic and Gulf of Mexico coasts, often with popular fisheries. These coastal populations must deal with the physiological stresses associated with salinity variation and may be isolated from inland freshwater populations, increasing the potential for differentiation. To understand factors important to the ecology and management of these coastal populations, we quantified individual- and population-level parameters for Largemouth Bass across a natural salinity gradient in the Mobile-Tensaw River delta in southwestern Alabama during 2002–2009 (including population demographics, feeding ecology, movement, recruitment, and bioenergetics processes). Combining traditional mark–recapture and telemetry techniques with otolith microchemical analyses, we demonstrated that Largemouth Bass of all ages moved very little, even in response to increasing salinity (up to 15‰) in downstream areas. Large individuals were rare in our sampling across both fresh and brackish habitats (only 7 out of 9,530 individuals were >2.27 kg), and fish body condition increased downstream with increasing marine influence. Growth responses for fish across the estuary were more complex, varying with both fish age and salinity. Faster growth was observed in the brackish, downstream areas for fish ≤age 2, while growth of older fish was faster in freshwater upstream sites. Using bioenergetics modeling, we demonstrated that a complex combination of spatial variation in water temperature, prey energetic content, and metabolic cost of salinity was responsible for age-specific spatial variation in growth. Preliminary genetic analysis suggests that these coastal Largemouth Bass may differ genetically from inland fish. Coastal Largemouth Bass populations face a number of potential conservation concerns, and their management will require different approaches compared to their inland counterparts, including different goals and expectations, likely even requiring consideration as unique stocks.


1981 ◽  
Vol 38 (12) ◽  
pp. 1715-1723 ◽  
Author(s):  
David P. Philipp ◽  
William F. Childers ◽  
Gregory S. Whitt

Genetic differences exist among 90 largemouth bass (Micropterus salmoides) populations from different geographic regions of the United States. Genetic variation at 28 loci was determined through the use of vertical starch gel electrophoretic analyses. Allelic polymorphism was observed at 16 of these loci. Marked differences in allele frequencies at six of these loci exist among the populations. Distinct north–south clinal distributions of the alleles at the MDH-B, SOD-A, IDH-B, and AAT-B loci suggest a possible involvement of the associated enzymes in the thermal tolerance/preference limits for this species.We conclude that one or more of these enzymes may be directly involved in temperature tolerance/preference or indirectly associated with temperature-related effects. In either instance, selection (if occurring) may be acting upon the enzyme locus or genes closely linked to it. Through a combination of ecological and genetic principles, it is becoming increasingly feasible to select or construct specific populations of marine or freshwater fish optimally suited for specific environments. Fisheries management programs would benefit from the application of these principles. Multidisciplinary approaches of this nature are essential to maximize the successful conservation and management of our natural resources.Key words: largemouth bass, allele, loci, polymorphism, selection, population


<em>Abstract</em>.—Stream restoration techniques in the southeastern United States have focused mostly on habitat manipulation. However, using simple and aggressive methodologies is necessary to promote cost effective methods of restoring habitat. A review of stream restoration practices is provided, with two detailed and different restoration scenarios presented, followed by a discussion on the effectiveness of these methods and lessons learned to help facilitate a range of options during the development of restoration goals and objectives.


<em>Abstract</em>.—We conducted a stock assessment of Shoal Bass <em>Micropterus cataractae</em> in the upper Chipola River in Jackson and Calhoun counties, Florida from 2007 to 2012 to aid in the species’ conservation. Shoal Bass are currently listed as a species of special concern by the American Fisheries Society and are a recreational sport fish species in Florida. Previous Shoal Bass research in Florida was limited in terms of quantified habitat use or population abundance. Although one of the potential threats to Shoal Bass in the Chipola River has been described as sedimentation, little information existed regarding abundance, growth, mortality, or fishing effort. Shoal Bass and sympatric Largemouth Bass <em>M. salmoides</em> were collected by electrofishing from three study reaches. Modified Schnabel population estimates from mark– recaptured fish were used to describe abundance in 2009, 2010, and 2011. A roving creel survey was conducted in 2010 and 2011 to provide effort, total catch, catch per unit effort (fish caught per angler-hour), and harvest estimates. Mean total length at age was described by von Bertalanffy growth curves for Shoal Bass collected in 2008 and 2010, and growth differed between years. Total annual mortality (<EM>A</EM>) for Shoal Bass averaged 57% and was greater than total annual mortality for Largemouth Bass (<EM>A </EM>= 32%, <EM>P </EM>= 0.009) at this system. Missing or underrepresented year-classes from the 2008 and 2010 Shoal Bass age samples suggested highly variable recruitment. Strong Shoal Bass year-classes were associated with low median flows and low flow variation in spring and summer. An abundant population of Shoal Bass exists in the Chipola River, and the fishery received low angling harvest and directed effort. However, Shoal Bass remain potentially threatened by sedimentation, variable hydrologic events, and its confined range and habitat requirements.


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