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1.
Yellow perch ( Perca flavescens ) have become one of the focal points in aquaculture in the Great Lakes region of the United States. In this paper, we reviewed existing information on nutrition of yellow perch and identified critical areas in need of development. Yellow perch are small at hatching (4–7 mm total length), and are difficult to feed. Zooplankton cultures remain the only viable means of mass propagation, but larvae can be trained to accept formulated feeds in ponds at the age of 30–45 days. Few nutritional requirements exist for yellow perch, thus there are no diets formulated specifically for this species. The current recommendations are use of feeds formulated for trout and salmon. Ongoing research efforts are underway that will improve our ability to feed yellow perch at all life history stages.  相似文献   

2.
Summary Densities of the cladoceran, Holopedium gibberum, were manipulated in 18 enclosures containing juvenile (age 0+) yellow perch (Perca flavescens) and mean-lake densities of other zooplankton. In enclosures, where nearlake densities of all zooplankton species including Holopedium were maintained, young-of-the-year perch grew significantly heavier and longer than in experimental enclosures where Holopedium was excluded. Holopedium comprised between 15–45% of the diet (wet weight) of perch in the first 2 weeks of July in the control treatment (Holopedium at or near ambient lake densities) and only 3–7% of total biomass ingested in the experimental treatment (Holopedium density selectively reduced). Predation on Holopedium decreased dramatically after the 2nd week of July in the control treatment after which Chaoborus, chironomids, and Sida became dominant prey items (by weight) of juvenile perch. These findings suggest that growth and survivorship of age 0+ perch in Precambrian Shield lakes may be coupled to Holopedium abundance. Thus, utilization of Holopedium by young-of-the-year yellow perch may affect recruitment of this species since overwintering survivorship, range of accessible prey sizes or species, and vulnerability of juvenile perch to predation by larger fish depend on body size, which is reduced when Holopedium is excluded from the diet.  相似文献   

3.
A total of 45 microsatellite loci from yellow perch, Perca flavescens, were isolated and characterized. Among the 45 microsatellite loci, 32 had more than two alleles. A wild population of P. flavescens (n = 48) was used to examine the allele range of the microsatellite loci. Mendelian inheritance of alleles was confirmed by examining the amplified products in pair‐mated families. The number of alleles for the 32 polymorphic loci varied from two to 16, and observed heterozygosity ranged between 0.024 (YP79) and 0.979 (YP60). Cross‐species polymorphic amplification in four other Percidae species was successful for 22 loci.  相似文献   

4.
Synopsis Relationships between sublethal concentrations of cadmium and zinc in natural water and metal uptake by and growth of fish were investigated. RNA-DNA ratios and weight gain were used to assess seasonal growth differences between yellow perch populations from contaminated and control sites. Whole-body concentrations of cadmium and zinc in young-of-the-year perch (Perca flavescens) were significantly different between sites. Measurable growth differences did occur and were significantly correlated with cadmium levels. Growth differences that were prominent during mid-summer were reduced by late summer. RNA-DNA ratios were sensitive indicators of fish growth.  相似文献   

5.
This study on yellow perch (Perca flavescens) examines a series of enzymatic markers and the relative weights of pyloric caeca and visceral lipids, their response to changes in feeding regime and their potential use to infer recent changes in growth rate and fish condition. Fish were exposed to four different feeding regimes for 12 weeks resulting in specific growth rates ranging from 0.3% to 3.5% (%/day). Growth and condition responded rapidly to changes in ration and the weight of pyloric caeca and visceral lipids reflected increased feed intake. Growth rate was correlated with muscle citrate synthase and caecal nucleoside-diphosphate kinase activities, whereas condition was correlated with muscle citrate synthase and lactate dehydrogenase activities and with caecal glucose-6-phosphate dehydrogenase activity. Results showed that enzyme activities and biometric parameters responded rapidly to increased feed intake, but the response was slower when food intake decreased. Plateaus were attained for both condition and visceral lipid index, but the relative weight of pyloric caeca continued to increase throughout the experimental period. Results from this study could, in principle, be used to infer recent growth and energy status in wild yellow perch and thus provide an indicator of food availability in their environment.  相似文献   

6.
We determined the diet of 1 to 1 1/2 a old yellow perch (Perca flavescens) in a Quebec reservoir, relative to occurrences of available prey species and size classes of prey. We used Schindler-Patalas trap samples taken over four 24-h intervals between June and September 1981 to determine size distribution of available prey species. Relative abundances and size distribution of ingested prey species were determined from examination of gut contents of perch trapped by gill nets during the same time intervals. Electivity values of different prey species and of different size classes of prey were determined. Larger zooplankton prey (e.g.Epischura andLeptodora) were generally preferred but there was considerable variability in diet among individual fish that cannot be explained by patterns of prey availability. Within particular size classes of prey, perch have definite preferences, e.g. when perch consume small prey, they preferBosmina to other similar-sized prey. These results are discussed in relation to theories attempting to describe and predict feeding patterns of planktivorous fish species.Deceased, June 6, 1983  相似文献   

7.
Landscape genetics is being increasingly applied to elucidate the role of environmental features on the population structure of terrestrial organisms. However, the potential of this framework has been little explored in aquatic ecosystems such as large rivers. Here, we used a landscape genetics approach in order to (i) document the population structure of the yellow perch ( Perca flavescens ) by means of genetic variation at microsatellite markers, (ii) assess to what extent the structure was explained by landscape heterogeneity, and (iii) interpret the relevance of interactions between genetics and landscape for management and conservation. Analysis of the genetic variation among 1715 individuals from 16 localities and distributed over 310 km in the freshwater section of the Saint Lawrence River (Québec, Canada) revealed a relatively modest level of genetic structuring ( F ST = 0.039). Application of the Monmonier's algorithm combining geographical and genetic information identified three zones of restricted gene flow defining four distinct populations. Physical barriers played a more important role on gene flow and genetic structure than waterway geographical distance. We found correlations between genetic differentiation and presence of distinct water masses in the sector of Lake Saint-Louis ( r =  0.7177, P  = 0.0340) and with fragmentation of spawning habitats in the sector of Lake Saint-Pierre ( r =  0.8578, P  = 0.0095). Our results support the treatment of four distinct biological units, which is in contrast with the current basis for yellow perch management. Finally, this study showed that landscape genetics is a powerful means to identify environmental barriers to gene flow causing genetic discontinuities in apparently highly connected aquatic landscapes.  相似文献   

8.
1. Isotopic signatures (δ15N and δ13C) from young‐of‐the‐year (YOY) yellow perch (Perca flavescens) were collected over the initial 4 month summer growing period from three separate and distinctive sites in northern Alberta, Canada. Data were analysed to test the hypotheses that there are within‐ and among‐population differences in the patterns of isotopic δ15N and δ13C change over the growing season, and that observed isotopic dilution and/or enrichment patterns were influenced by site‐specific physical and chemical factors. 2. Increases in δ15N relative to spawned egg masses were observed in immediate posthatch (emergent) YOY and attributed to enrichment associated with the assimilation of yolk during embryonic development. 3. Posthatch dilution of YOY δ15N signatures associated with ontogenetic dietary shifts from yolk to exogenous feeding and zooplanktivory to benthivory occurred at all sites and was associated at most sites with a concomitant increase in δ13C. 4. The rate and pattern of δ15N dilution and δ13C enrichment observed for the study populations varied between and within sites and depended on maternal trophic status and timing of ontogenetic dietary shifts, as determined by prey availability and site‐specific biogeochemical factors. 5. Comparisons of isotopic dilution patterns among species, using results from this study and literature‐derived values, indicated that dilution rates and patterns are species dependent and may vary in relation to key life‐history events. 6. Seasonal and spatial isotopic variability among populations and between species complicates field sampling. In particular, the connectivity to site‐specific conditions found here suggests that for locally resident juvenile fishes, spatial, as well as temporal variability must be included in isotopic sampling programmes designed to characterise littoral zone foodweb relationships.  相似文献   

9.
In both yellow perch ( Perca flavescens ) and walleye ( Stizostedion vitreum ), females grow significantly faster and reach a larger ultimate size than males. In addition, reproductive development in both of these species can have a significant negative impact on somatic growth and fillet yield. Accordingly, methods for producing monosex female populations and for inducing sterility, have important potential applications for both commercial fish culture and fisheries management. Of the several available methods for producing monosex female populations in fishes (such as yellow perch and walleye) in which females are homogametic, the preferred method (described herein) may be to treat juveniles with androgens to induce phenotypic sex inversion of genetic females, and to subsequently use sperm from these females to fertilize normal eggs. Initial efforts at inducing sterility focused on the direct use of either heat or hydrostatic pressure shocks to produce triploid yellow perch and walleye. The gonadal development of triploid yellow perch and walleye of both sexes is retarded compared to that of diploids, and triploid yellow perch can have higher fillet yields than diploids. The direct use of heat and pressure shocks to induce triploidy in yellow perch, however, has negative effects on growth that are independent of ploidy status. One way to circumvent this problem is to produce triploids by crossing fertile tetraploids with diploids. To date, methods of producing viable tetraploids (beyond the larval stage) have been developed for yellow perch but not for walleye.  相似文献   

10.
11.
Concentration factor and biological half-life of 54Mn were determined in three species representing an ecologically and economically important food chain. Green algae (Chlorella spp.), Daphnia magna and yellow perch (Perca flavescens) were exposed to 54Mn in water and assayed for 54Mn uptake. Steady state concentration factors computed from the laboratory data for algae, Daphnia and perch were 4230, 17 000 and 11, respectively. Respective biological half-lives were 1.6, 1.2 and 8.3 days.  相似文献   

12.
Bluegill (Lepomis macrochirus) and yellow perch (Perca flavescens) populations are often sympatric in the Great Plains region of the U.S.A. and portions of Canada; however, very little attention has been given to potential interactions between these species for available resources, especially during the early life stages. Relationships between age-0 bluegill and yellow perch growth and relative abundance were explored across multiple lakes and years within the Nebraska Sandhill region, USA. In addition, four habitat patch types (open water, Phragmites spp., Typha spp., Scirpus spp.) were sampled for age-0 bluegill and yellow perch, and food habits were examined for each species during August, September, and October of 2009 in one of these lakes. Age-0 yellow perch growth was negatively related to age-0 bluegill relative abundance across a spatiotemporal scale. Age-0 bluegill and yellow perch exhibited similar habitat use (moderate–high overlap), but generally consumed different important and dominant prey taxa (bluegill consumed both macroinvertebrates—56?% and zooplankton—44?%, while yellow perch consumed more zooplankton—66?%), which resulted in low overall diet overlap between species. Previous research indicates that age-0 yellow perch diet ontogeny often results in feeding predominately on macroinvertebrates and positively selecting them (and avoiding zooplankton prey) at sizes observed in our study. Therefore, yellow perch growth rates may be compromised by the presence of bluegill because of the need to consume less energetically profitable prey items such as zooplankton.  相似文献   

13.
Laboratory experiments were conducted to determine how larval and juvenile yellow perch Perca flavescens respond to changes in prey density when exposed to different levels and types of turbidity (phytoplanktonic or sedimentary). Across prey densities, consumption by P. flavescens tended to be less in phytoplanktonic turbidity compared with sedimentary turbidity. For larvae, this effect was dependent on turbidity level (consumption differed between turbidity types only at high turbidity), while for juveniles the difference with turbidity type was equal across turbidity levels. These results suggest that phytoplankton blooms are detrimental to the ability of late season age 0 year P. flavescens to forage and support the need to control factors leading to excessive phytoplankton growth in lakes.  相似文献   

14.
Differences in the foraging strategies among young individuals of the yellow perch (Perca flavescens) were observed in the laboratory by using two kinds of food (Daphnia and brine shrimp) separately and together. Individuals differed significantly in their ability for feeding attempts, time interval between two consecutive feeding attempts, feeding angles, regurgitation rate, and number of unsuccessful attempts and in their food preference. It is concluded that there are individuals with different foraging strategies. Variability in foraging strategies within single species populations is important because it may explain how the conspecific individuals may differ in their overall feeding behaviour.  相似文献   

15.
Synopsis Acidification of the lakes of the La Cloche Mountains, Ontario, has reduced population densities of the yellow perch. Yellow perch of age groups 1 to 3 responded with increased rates of growth. Yellow perch of age groups 4 to 9 responded with reduced rates of growth. On the basis of these findings it is suggested that the growth rate of yellow perch may serve as a valuable indicator of environmental stress. Based on a thesis submitted by P.M.R. in conformity with the requirements for the degree of Master of Science in the University of Toronto.  相似文献   

16.
1. For many fish species, survival during early life stages is linked to the size and energetic condition of females prior to reproduction. For example, females in good energetic condition are often more fecund and produce larger eggs and offspring than those in poor condition. 2. We measured the characteristics of female yellow perch (Perca flavescens) that may influence annual population fluctuations. From 2005 to 2007, we measured spatial variation in female reproductive traits, such as age, length, mass and energy density (J g?1) of somatic tissues and ovaries among four spawning aggregations of yellow perch in western and central Lake Erie. 3. Maternal traits, such as somatic energy density and spawner age distribution, differed between the western and central basin, whereas reproductive traits, such as fecundity and ovarian energy density, differed across years. 4. To understand the implications of observed differences in demographic rates (growth and mortality rates) between basins, we developed a deterministic model to simulate the total egg production in the western and central basins under different scenarios of fishing mortality. 5. High growth rates and low mortality rates combined to produce higher modelled estimates of total egg production in the central than in the western basin, and a larger proportion of eggs were produced by old age classes in the central basin than in the western basin. 6. Our results demonstrate that changing harvest levels for populations with different demographic rates can influence total reproductive output through complex interactions between age‐specific mortality, growth and size‐specific fecundity, which has implications for the population dynamics of yellow perch and related species across a broad geographic range.  相似文献   

17.
1. Previous studies in a variety of ecosystems have shown that ecologically and economically important benthic and bentho‐pelagic fishes avoid hypoxic (<2 mg O2 L?1) habitats by moving vertically or horizontally to more oxygenated areas. While avoidance of hypoxic conditions generally leads to a complete shift away from preferred benthic prey, some individual fish continue to consume benthic prey items in spite of bottom hypoxia, suggesting complex habitat utilisation and foraging patterns. For example, Lake Erie yellow perch (Perca flavescens) continue to consume benthic prey, despite being displaced vertically and horizontally by hypolimnetic hypoxia. 2. We hypothesised that hypolimnetic hypoxia can negatively affect yellow perch by altering their distribution and inducing energetically expensive foraging behaviour. To test this hypothesis, we used drifting hydroacoustics and trawl sampling to quantify water column distribution, sub‐daily vertical movement and foraging behaviour of yellow perch within hypoxic and normoxic habitats of Lake Erie’s central basin during August‐September 2007. We also investigated the effects of rapid changes in ambient oxygen conditions on yellow perch consumption potential by exposing yellow perch to various static and fluctuating oxygen conditions in a controlled laboratory experiment. 3. Our results indicate that, while yellow perch in general avoid hypoxic conditions, some individuals undertake foraging forays into hypoxic habitats where they experience greater fluctuations in abiotic conditions (pressure, temperature and oxygen concentration) than at normoxic sites. However, laboratory results suggest short‐term exposure to low oxygen conditions did not negatively impact consumption potential of yellow perch. 4. Detailed understanding of sub‐daily individual behaviours may be crucial for determining interactive individual‐ and ecosystem‐level effects of stressors such as hypoxia.  相似文献   

18.
Proteolytic activity was measured in the follicle wall surrounding oocytes from brook trout (Salvelinus fontinalis) and yellow perch (Perca flavescens) by use of two different protease assays: sodium dodecyl sulfate-polyacrylamide gel electrophoresis (substrate-SDS-PAGE) and a chromogenic synthetic peptide for type I collagen. In brook trout follicle walls, substrate-SDS-PAGE studies demonstrated that the activity of two proteolytic enzymes (80 kDa and 66 kDa) increased significantly before ovulation. The 80 kDa enzyme decreased significantly after ovulation whereas the 66 kDa enzyme remained elevated following ovulation. In yellow perch follicle walls, substrate-SDS-PAGE studies demonstrated that the activity of the major protease (66 kDa) increased before ovulation and remained elevated after ovulation. A chromogenic synthetic peptide was used to assay collagenolytic activity in follicle walls of brook trout and yellow perch. This assay revealed that collagenolytic activity increased significantly in both species before ovulation and remained elevated after ovulation. These findings suggest that metallo-proteases are involved in digesting the follicle wall in teleosts before and after ovulation.  相似文献   

19.
Synopsis Stunting in freshwater fish populations may be due to low availability of one or more prey components within their diet. If the limiting prey constitute a trophic level (i.e. zooplankton, benthos, or fish), we define the phenomenon as a trophic bottleneck. Growth of a non-stunted population of yellow perch, Perca flavescens, was simulated using an allocation model based on reported ontogenetic shifts in diet (planktivory to benthivory to piscivory). The model was then perturbed by limiting the available ration individually for each of the three feeding types. The resulting simulated growth curves all reflected lower growth rates than the unperturbed state and the shape of the curve differed between the limited food types. Only the reduced benthic ration produced a simulated growth that matched that observed for the stunted yellow perch of Lac Hertel (Québec). To test the hypothesis that benthic ration was limiting growth in Lac Hertel, all the fish species in the lake were sampled for diet composition and total length at age. We predicted that species feeding upon benthic invertebrates should exhibit the slow growth characteristic of stunting (based on the results of the allocation model). Of the seven fish species found in Lac Hertel, four were stunted: yellow perch, pumpkinseed, Lepomis gibbosus, rock bass, Ambloplites rupestris, and brown bullhead, Ictalurus nebulosus. Three species were non-stunted: northern pike, Esox lucius, golden shiner, Notemigonus crysoleucas, and white sucker, Catostomus commersoni. All stunted species fed on benthic invertebrates and all non-stunted species, except the white sucker, did not feed upon benthos. The prediction of the allocation model was thus supported.  相似文献   

20.
Previous work showed that goldfish learn to avoid a region of an aquarium where they receive a discrete shock to the flank. This avoidance is reduced if another fish is present next to the shock zone, suggesting fish trade-off avoidance against a tendency to associate [Dunlop, R., Millsopp, S., Laming, P., 2006. Avoidance learning in goldfish (Carassius auratus) and trout (Oncorhynchus mykiss) and implications for pain perception. App. Anim. Behav. Sci. 97 (2–4), 255–271]. Only shock intensity was adjusted in those experiments, here we report results where a requirement for food was also altered.Fish were trained to feed at a region of the aquarium where subsequently they would receive a discrete shock to the flank. One experimental group had different shock intensities applied, whereas in the other group shock intensity was consistent but food deprivation was varied.We show the number of feeding attempts and time spent in the feeding/shock zone decreased with increased shock intensity and with increased food deprivation the number and the duration of feeding attempts increased as did escape responses as this zone was entered. These data suggest that goldfish balance their need for food against avoidance of an acute noxious stimulus.  相似文献   

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