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1.
Abstract  During live-release angling tournaments in North America, fish are typically retained in livewells onboard boats during the angling day. Mortality of fish occurs at some tournaments, and wave intensities and livewell conditions may influence mortality levels. This study used two species of fish targeted in live-release angling tournaments in North America (largemouth bass Micropterus salmoides L. and walleye Sander vitreus L.) to quantify the response(s) of fish in livewells to different wave treatments. Video analyses revealed that largemouth bass were active during low intensity disturbances, but during violent boat movements tended to settle to the bottom of the livewell and orient to face the direction of the disturbance. Walleye were less active than bass for all treatments, and additionally did not orient to face the direction of disturbance, consequently contacting the side of the livewell during boat rocking. These results are considered in the context of mortality at live-release tournaments.  相似文献   

2.
Abstract  Largemouth bass, Micropterus salmoides (Lacepède), smallmouth bass, Micropterus dolomieu Lacepède, and yellow perch, Perca flavescens (Mitchill), were collected from the Hudson River, New York, USA, to compare the precision of age estimates derived from scales and otoliths. Similar procedures were used to compare otolith and spine ages from brown bullhead, Ameiurus nebulosus (Lesueur). Overall percent agreement between readers ranged from 91% to 98% for otoliths compared with 38% to 67% for scales and spines. Disagreement rates associated with scales and spines increased as fish grew older. Average percent error between readers was about an order of magnitude higher for scales and spines than for otoliths. Ages estimated from scales and spines progressively decreased as age increased based on otolith examination. The use of scales and spines to age largemouth bass, smallmouth bass, yellow perch and brown bullheads from the northeastern US was less precise and will likely lead to underestimation of age of larger and older fish.  相似文献   

3.
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4.
Abstract Variation in brood abandonment was explored by conducting partial brood removals from smallmouth bass, Micropterus dolomieu Lacepède, nests in two north temperate lakes. In both lakes, percent of the brood removed had no effect on nest failure rates. Nest failure prior to offspring swim‐up was more common, but unrelated to brood size after removal, in the lake with higher post‐spawning mortality and lower growth and fecundity. Brood size after removal was negatively related to nest failure in the lake with high survival, growth and fecundity. Nests guarded by young males failed more frequently than those of old males, and young broods failed more frequently than old broods. Dynamic programming and logistic regression models developed to predict nest fate worked better for the lake with selective pressures that theoretically favoured abandonment (e.g. high post‐spawning mortality). Both models identified male age and brood age as important factors in predicting nest fates. Because nest success is related to the age of the parent, this could have consequences for overall nest success for populations with different demographics.  相似文献   

5.
When break-offs occur during recreational angling, lures may be retained by the fish. To date, there have been few studies on the consequences of lure retention on sportfish. This study evaluated how the retention of three different types of lures (i.e., crankbait, jig and plastic worm—all with barbed hooks) influenced the behaviour, physiology and reproductive success of nesting, male smallmouth bass (Micropterus dolomieu) relative to controls released after lure removal. Bass were angled from their nests and subjected to a simulated lure retention scenario in which one of three lure types was placed in the upper middle jaw. Males were subsequently released and their behaviour (time to return to nest, parental care behaviour) was monitored. Immediately after release, fish with retained lures exhibited altered behaviour relative to control fish, attempting to expel the lure. However, these differences in behaviour were no longer apparent after 24 h even for those fish that retained the lures. Rates of nest abandonment did not differ between treatment and control fish in the short term. Fish were rarely able to liberate themselves from the retained lure in the several days post-treatment. Physiological sampling conducted on jig treatment fish and angled controls revealed elevated blood glucose concentrations in fish that had retained lures for 24 h, while lactate concentrations and hematocrit did not differ between treatment and control fish. These results demonstrate that lure retention in the short-term influences both the behaviour and physiology of smallmouth bass. Given that lures were generally retained throughout the study period, there may be merit in anglers using barbless hooks that may be more readily shed by fish that break the line, reducing the welfare impacts associated with lure break-offs on wild fish. Additional studies are needed to understand the longer term consequences of lure retention in free-swimming fish.  相似文献   

6.
Abstract. Fifty each of F2-generation gold ( gg ), bronze ( Gg ), and black ( GG ) Oreochromis mossambicus (Peters) and either zero, four or eight largemouth bass, Micropterus salmoides , (Lacepède) were stocked in 20-m2 concrete tanks. After 7 days, water in all tanks was drained, and fish in each tank were censused. Largemouth bass ate 18% of the tilapia in the four-bass treatment (1 tilapia/bass/day) and 60% of the tilapia in the eight-bass treatment (1·6 tilapia/bass/day); the difference was significant (P=0–05). In the four-bass treatment there was a greater observed mean predation rate on gold than that on black or on bronze tilapia, but the difference was not significant: largemouth bass ate 25% of the gold tilapia, 16% of the bronze tilapia, and 13% of the black tilapia. In the eight-bass treatment, predation on the gold tilapia was significantly greater than that on both bronze (P=0·05) and on black (P=0·06) tilapia; predation on bronze and black tilapia was similar: largemouth bass ate 80% of the gold tilapia, 48% of the bronze tilapia, and 51% of the black tilapia. Overall average total predation (both treatments combined) on gold tilapia was significantly (P=0·06) greater than that on both bronze and on black tilapia, which did not differ: largemouth bass ate 52% of the gold tilapia, 32% of the bronze tilapia, and 32% of the black tilapia. The increased vulnerability of gold tilapia to predation was a negative pleiotropic effect of the gg genotype.  相似文献   

7.
Abstract. The Formosa snakehead, Channa maculata (Lacepède), and the largemouth bass, Micropterus salmoides (Lacepède), were given an intraperitoneal (i.p.) and/or intramuscular (i.m.) inoculation of Nocardia asteroides isolated from cultured Formosa snakehead, Typical granulomatous lesions induced by the experimental fish were similar to the naturally infected cases. The Formosa snakehead showed 100% and 93% mortality at 14 and 35 days after i.m. inoculation with 8 mg and 0·8 mg of bacterial suspension, respectively. The largemouth bass was slightly resistant to N. asteroides but still had 95% mortality at 35 days after inoculation (i.m.) with 8 mg bacterial suspension. The bacteria were easily reisolated from spleen and kidney of the experimental fish. Many typical multifocal granulomata were found at the sites of injection and the internal organs such as liver, spleen, kidneys, pancreas, intestine, gills, eyes and brain. The result indicated that the N. asteroides isolated from the field ease was pathogenic to Formosa snakehead and largemouth bass.  相似文献   

8.
Catch‐and‐release angling is popular in many parts of the world and plays an increasingly important role in management of recreational fisheries. Although the magnitude of catch‐and‐release mortality is well documented for many species, potential sublethal effects have been little studied. An experiment was conducted to assess directly the effects of catch‐and‐release angling on growth of largemouth bass, Micropterus salmoides Lacépède. Angling mortality was 0.00 ± 0.092% for largemouth bass caught on plastic grubs. There was no difference (P = 0.57) in weight gain between caught and uncaught fish over a 40‐day angling and recovery period. Although catch‐and‐release angling appears to have no effect on largemouth bass growth, previous studies documented sublethal effects on growth and reproduction in other species, suggesting that the occurrence and magnitude of sublethal effects vary among species.  相似文献   

9.
Activity patterns of largemouth bass in a subtropical US reservoir   总被引：1，自引：0，他引：1  
Abstract  Nine largemouth bass, Micropterus salmoides Lacepède, >1.5 kg were implanted with radio tags and tracked for 1 year in an embayment of Lake Seminole, Georgia, USA. Most largemouth bass movement was <50 m h−1 in all seasons and at all times of day. During the day largemouth bass were offshore in deeper water near large woody structures and moved little. Movement was lower during dusk and night periods, and a general movement towards shoreline areas was evident. Water depths where largemouth bass were located had bimodal distributions in all seasons and diel periods, with one mode typically at depths <1 m and another around 3 m. Home ranges were typically largest in the summer and smallest in the winter. Largemouth bass appeared to divide their time between an offshore resting area, primarily occupied during the day, and a near-shore area, where foraging presumably occurred, primarily used during low-light periods. The largemouth bass population in Lake Seminole consists of multiple overlapping subpopulations, offering the opportunity for embayment-specific management.  相似文献   

10.
Abstract  Standard methods for comparing population characteristics within and among fish populations greatly enhance communications among fisheries scientists, improve the efficiency of data analysis, and provide insight that helps guide management actions. Although standard methods are available for comparing some fish population characteristics (e.g. length structure, body condition), similar methods are lacking for comparing growth. The purpose of this study was to provide standards (i.e. percentiles and a standard growth model) for nine ecologically and recreationally important fish species. Percentile distributions of mean back-calculated length at age were estimated using data obtained from the published literature and from data solicited from state and federal agencies throughout North America. Percentiles of growth were estimated for bluegill, Lepomis macrochirus Rafinesque, common carp, Cyprinus carpio Linnaeus, flathead catfish, Pylodictis olivaris (Rafinesque), largemouth bass, Micropterus salmoides (Lacepède), sauger, Sander canadensis (Griffith & Smith), smallmouth bass, Micropterus dolomieu Lacepède, white bass, Morone chrysops (Rafinesque) and yellow perch, Perca flavescens (Mitchill). Standard growth models (i.e. von Bertalanffy models) were developed for these species and for channel catfish, Ictalurus punctatus (Rafinesque). These results provide tools that will help scientists compare growth of fishes across North America.  相似文献   

11.
Abstract  Removal of piscivores may affect population size structure, abundance and growth rates of the remaining fish community. A total of 572 northern pike, Esox lucius L., was removed from 25-ha West Long Lake, Nebraska from 2003 to 2006. The northern pike population was reduced from 36 fish ha−1 and 22 kg ha−1 in 2002 to 20 fish ha−1 and 9 kg ha−1 in 2006. The northern pike population shifted to dominance by smaller individuals. Relative abundance increased for bluegill, Lepomis macrochirus Rafinesque, but remained similar between years for largemouth bass, Micropterus salmoides (Lacepède), and yellow perch, Perca flavescens (Mitchill). Bluegill and yellow perch size structure increased probably because of reduced predation by northern pike. The effects of reduced northern pike density on largemouth bass were less evident. The largemouth bass population may be returning to higher density with smaller size structure observed before pike were introduced. The sport fish community responded positively to the removal of northern pike in this small lake.  相似文献   

12.
Diet overlap in a piscivore community   总被引：1，自引：0，他引：1  
Abstract— We examined prey selection of largemouth bass ( Micropterus salmoides ), smallmouth bass ( M. dolomieu ), and yellow perch ( Percaftavescens ) by comparing diet overlap in a small, unexploited lake in Michigan, USA from 1988 to 1990. Niche hypervolume principles were applied to diet data as a means of assessing diet space for each species and the community as a whole. Largemouth bass occupied the largest proportion of community diet space (70.2%), followed by smallmouth bass (44.2%), and yellow perch (21.7%). The majority of community diet space (58.8%) was occupied by a single species, and 41.2% was shared by ≥ 2 species. Diet overlap was assessed by measuring the amount of diet space of one species occupied by the other species. Our analyses demonstrated that diet partitioning in a three species piscivore community is reflected in different use of the prey resource by co-occurring species. Niche overlap of largemouth bass with smallmouth bass and yellow perch is strongly asymmetric, largely due to the ability of largemouth bass to effectively consume prey of terrestrial origin.  相似文献   

13.
Abstract  This paper summarises recent peer-reviewed literature addressing the effects of catch-and-release angling on black bass, Micropterus spp., to facilitate management and conservation of these fish. Traditionally, the effects of catch and release have been evaluated by measuring mortality. Many recent studies have measured sublethal effects on physiology and behaviour. There is also greater emphasis on adding more realism to sublethal catch-and-release experiments through angler involvement in research activities and by conducting studies in the field rather than in laboratory environments. Owing to these advances, there have been a number of recent findings, which are summarised here, related to air exposure, gear (e.g. circle hooks) and the weigh-in procedure that are particularly relevant to black bass anglers, tournament organisers and fishery managers. Additional research is particularly needed for: (1) population-level effects of angling for nesting fish; (2) population-level effects of tournament-associated mortality; (3) effectiveness of livewell additives for enhancing survival; (4) consequences of fish displacement in competitive events; (5) effects of weigh-in procedures and other organisational issues on fish condition and survival; and (6) reducing barotrauma.  相似文献   

14.
Millions of Florida bass, Micropterus floridanus Lesueur, are stocked annually into populations of largemouth bass, Micropterus salmoides Lacepède, to increase trophy fish abundance. However, little effort has related the role that resultant hybrids make to angler catches. Largemouth bass were sampled from an important recreational fishery subject to extensive Florida bass stocking to address the hypothesis that anglers capture Florida bass, largemouth bass and hybrids at rates equivalent to their overall abundance in the population. Fin clips obtained from tournament angling events (n = 348) and boat‐mounted electrofishing sampling (n = 219) were screened at 38 species‐diagnostic markers and individuals were assigned to genealogical classes using Bayesian clustering algorithms. No significant differences were identified between angler and electrofishing catches providing evidence that hybridised individuals stemming from a long‐term stocking programme may constitute an important contribution to tournament angling catch.  相似文献   

15.
Tournament fishing has risen in popularity over the last half a century. As such, social and financial incentives combined with technological advancements are expected to drive changes in angler's capacity to exploit tournament‐eligible fish stocks, as has been observed in commercial fisheries. The aim of this study was to quantify temporal trends in angler efficiency and their ability to exploit a given fish stock relative to effort in largemouth bass fishing tournaments. A collective analysis across seven Illinois reservoirs comparing change through time in angler catch rates and relative population abundances indicated that angler efficiency has generally improved through time. For the decade from 2005 to 2015, a greater than threefold increase in the efficiency of anglers to exploit a static population of largemouth bass was estimated. Anglers have become more efficient at exploiting populations, which is likely to influence management decisions in the future, particularly in harvest‐orientated fisheries and those reliant upon fishery‐dependent surveys.  相似文献   

16.
Abstract  During the summer of 1990 the diet of Micropterus salmoides (Lacepède) was studied in four southern Portuguese reservoirs. The dominant food items were insects (especially Odonata and Ephemeroptera naiads, and Odonata and Hemiptera adults), the crayfish, Procambarus clarkii (Girard), and pumpkinseed sunfish, Lepomis gibbosus (L.). There was an increase in the consumption of L. gibbosus as bass changed from 100–200 mm total length to over 200 mm, and a corresponding decline in the insect and crayfish components. Carp, Cyprinus carpio L., and other benthic cyprinids were absent from the stomach contents. The association between the different prey consumed and the habitat characteristics are discussed in relation to the feeding ecology of largemouth bass, an exotic species in Portugal.  相似文献   

17.
One strategy for protecting the federally listed fountain darter, Etheostoma fonticola (Jordan & Gilbert), during low flow conditions is the removal of piscine carnivores [in this case, largemouth bass, Micropterus salmoides (Lacepède)]. However, headwater spring communities of the Comal and San Marcos rivers include another potential predator [red swamp crayfish, Procambarus clarkii (Girard)]. Removal of piscine carnivores could produce cascading effects by increasing crayfish consumption of benthic fish. The purpose of this study was to evaluate if piscine carnivore removal will lessen predatory pressure or induce a trophic cascade with crayfish increasing and causing declines in fountain darter. The numbers of fountain darter consumed were quantified among three predator treatments (red swamp crayfish only, largemouth bass only and red swamp crayfish and largemouth bass combined) and vegetation treatments (vegetated and non‐vegetated) at three temperature regimes (18, 22, 27°C). Vegetation had no effect on fountain darter predation. Among temperature trials, largemouth bass only and red swamp crayfish and largemouth bass combined consumed similar numbers of fountain darter, and red swamp crayfish only consumed the least numbers of fountain darter, except at 22°C. Largemouth bass did not consume more red swamp crayfish than fountain darter. Therefore, largemouth bass removal appears to be a viable option for reducing fountain darter predation during periods of low flow.  相似文献   

18.
Abstract The major food items of adult largemouth bass, Micropterus salmoides (Lacepède), in Lake Naivasha, Kenya are not markedly different from those in its native range. Although insects and their larvae are major components of the diet for both temperate and equatorial populations of juvenile bass, the equatorial population also eats Procambarus clarkii (Girard), juvenile fish and aquatic weeds. In temperate populations they also eat crustaceans, rotifers and oligochaetes. The frequency of occurrence of the major prey organisms in the stomachs of M. salmoides varies seasonally with population peaks in these organisms. Similar to North American populations, the Naivasha population feeds during the day between dawn and dusk. In contrast to temperate populations, the population of M. salmoides in this equatorial lake feeds throughout the year, with feeding intensity correlated with water temperature.  相似文献   

19.
Abstract – We assessed temporal dynamics and variation among species and age-classes in the diets of age 0 and age 1 piscivorous fish species in Spirit Lake, Iowa, USA during 1997 and 1998. Species included walleye Stizostedion vitreum , yellow perch Perca flavescens , smallmouth bass Micropterus dolomieui , largemouth bass Micropterus salmoides , black crappie Pomoxis nigromaculatus and white bass Morone chrysops. Thirty taxa were identified in diets, including 12 species of fish. We found dramatic differences in diets among species, among age-classes within species and over time. Walleye, largemouth bass, smallmouth bass and white bass were piscivorous at age 0. Black crappie began piscivory at age 1. Yellow perch also began piscivory at age 1, but fish were a very small fraction of age-1 diets. The primary temporal pattern, seen in several species and age-classes, was an increase in piscivory from spring to fall. This pattern was due to the lack of small, age-0 prey fish in spring. Although some patterns were evident, the taxonomic composition of the diets of all species was highly variable over time, making generalizations difficult. A surprising result was the absence of yellow perch in the diet of age-0 walleye, despite their abundance in Spirit Lake and prominence in diets of age-1 walleye and other age 1-piscivores. Age-0 yellow perch were consistently too large to be eaten by age-0 piscivores, which preyed primarily on invertebrates and smaller fish such as johnny darters Etheostoma nigrum and age 0 bluegill Lepomis macrochirus. This finding suggests that predator-prey interactions and resulting population dynamics may be quite different in Spirit Lake than in other systems dominated by walleye and yellow perch.  相似文献   

20.
Angler satisfaction is based on the presence of catchable fish, and therefore, understanding the mechanisms driving catchability is important for fisheries biologists and managers. Lure avoidance learning (including via social learning) may be a driver of catchability, but these mechanisms have not been explored in depth. To address this, largemouth bass, Micropterus salmoides (Lacépède), were stocked into four ponds, and two were angled using a green plastic worm. Naïve bass were then introduced into all ponds, and angling commenced using a sequence of three lures (green plastic worm, white plastic worm and in‐line spinnerbait). Naive bass stocked alongside experienced conspecifics were not less catchable, indicating socially learned lure avoidance did not take place. Catch rates declined across sessions until the switch to the spinnerbait, when rates temporarily spiked. This suggests that the similarity of a novel lure to previously experienced lures may determine if a fish avoids angling capture.  相似文献   

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