Nutrition and feeding of yellow perch (Perca flavescens)

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.     

Isolation and characterization of microsatellites in yellow perch (Perca flavescens)

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.     

Use of enclosures to detect the contribution of particular zooplankton to growth of young-of-the-year yellow perch (Perca flavescens Mitchell)

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.     

Physiological correlates of growth and condition in the yellow perch (Perca flavescens)

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.     

Mycobacteriosis in yellow perch (Perca flavescens) from two lakes in Alberta

Granulomatous skin lesions were identified in a population of yellow perch (Perca flavescens) from Sandy Lake (Alberta, Canada) in 1985. Severe granulomatous peritonitis and hepatitis was identified subsequently in a separate population of yellow perch from Wolf Lake (Alberta, Canada). Mycobacterium chelonae was isolated from affected fish in both epizootics. The source and route of infection were not determined in either case. The nature of the inflammatory reaction in both cases suggested a depressed immunity.     

Variation in diet of yellow perch (Perca flavescens) in a Quebec reservoir

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     

Diet and intestinal helminths in a population of perch, Perca flavescens

In 1967 and 1968 1310 Perca flavescens (Mitchill) were examined from Lake Opeongo, Ontario for changes in five diet categories and in incidence of eight intestinal helminths in relation to seasons, host size and sex. Male fish were less common than females and were smaller. A high proportion of fish (57.7 %) had empty stomachs, but of the four types of foods taken microcrustacea were high in spring, late summer and again in early winter; insects increased in summer with another peak in autumn; crayfish had a small peak in spring and a larger one in autumn; and fish were lowest in summer. Males ate more smaller foods (microcrustacea) than females, but females ate more larger foods (crayfish and fish); no sex difference was seen with regard to insects or empty stomachs. Male fish ate very few larger items, but females showed an increase in food size with increasing size of fish. There was no seasonality in incidence of fish free of all parasites, but two trematodes Bunodera sacculata Van Cleave & Mueller and B. luciopercae (Müller), and one cestode Proteocephalus pearsei La Rue showed seasonality with populations lowest in fish in summer; and one trematode Crepidostomum cooperi Hopkins and one nematode Dacnitoides cotylophora Ward & Magath showed seasonality with populations highest in summer. In addition one cestode Bothriocephalus sp., one nematode Spinitectus gracilis Ward & Magath and one acanthocephalan Leptorhynchoides thecatus (Linton) showed no seasonality, perhaps on account of the low incidence in the case of Bothriocephalus sp. and L. thecatus. No parasites were more common in males, but two (P. pearsei and L. thecatus) were more common in females. In both males and females, with increasing size fish, (i) fish free of all parasites decreased, but (ii) incidence of C. cooperi increased. Incidence of B. luciopercae, Bothriocephalus sp., S. gracilis and L. thecatus all increased with increasing size of fish only in females. The relationship between diet and incidence of intestinal helminths is discussed in the light of what is known of their life cycles. The exercise illustrates our ignorance of population ecology of fish parasites and the interactions of parasites and their host populations.     

Reproductive physiology of yellow perch (Perca flavescens): environmental and endocrinological cues

An understanding of the mechanisms involved in the regulation of reproductive processes in yellow perch is fundamental for intensive culture of this commercially important, freshwater, perciform fish. This paper describes the annual reproductive cycle of female and male perch. It presents the current state of knowledge on the regulation of ovarian steroidogenesis, final maturation of oocytes and ovulation in this species. Moreover, data concerning biochemistry of spermatozoa and seminal plasma as well as testicular steroidogenesis are summarized. In addition to endocrinological factors, the involvement of environmental (photoperiod and temperature) cues in the regulation of yellow perch reproduction is reviewed. Finally, practical aspects of controlling perch reproduction are outlined.     

Factors affecting the early life history of yellow perch,Perca flavescens

Synopsis From 1979 to 1981 we followed the movement, diet, and growth of yellow perch,Perca flavescens, for their first 70 days after hatching in Lake Itasca, Minnesota. Perch spawned inshore during early spring; hatching occurred 10–20 days after spawning. Newly hatched perch were 5.6–6.2 mm total length (TL). Soon after hatching the larvae moved into the limnetic zone where they began feeding. This movement is probably a mechanism to escape intense predation in the littoral zone. Normally the first food of perch was immature copepods, but within a week they incorporated all common zooplankters into their diet. When the perch reached 25 mm TL (about day 40) they returned to the littoral zone, where they ate larger and more abundant prey than was present in the limnetic habitat. There is no correlation between growth rates and zooplankton abundances, which suggests that food quantity is not a limiting factor in the early life history of perch in Lake Itasca.     

Sex control and ploidy manipulations in yellow perch (Perca flavescens) and walleye (Stizostedion vitreum)

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.     

Behavioural salinity preference of juvenile yellow perch Perca flavescens

The present study determined the behavioural salinity preference of a freshwater stock of juvenile yellow perch Perca flavescens acclimated to salinities of 0 and 10. The preferred salinities ranged between 7·3 and 13·0 (mean ± s.d . = 10·4 ± 1·7; n = 13) with no significant effect of acclimation salinity. The results showed that juvenile P. flavescens prefers near isoosmotic salinities, which could be due to a lowered energetic cost of osmoregulation.     

Diet overlaps and feeding relationships between the year classes in the yellow perch (Perca flavescens)

Synopsis A comparative study of the diets of five year classes of perch in Lake Opinicon showed Year class 0 to be mainly Cladocera feeders, the Year class 11 to take a diversified range of insect larvae, whereas from Year class V onwards Anisoptera nymphs, decapods, and fish dominated the diet. Sizes of the dominant food items changed strikingly with growth, prey weights of 0.1, 0.5–1.0, and 100–250 mg predominating in these three age groupings. There were marked month to month changes in types and proportions of different prey consumed.Overall and month to month feeding overlaps between consecutive year classes were considerable, most values ranging from 0.68–1.0 by the Levins formula. However, diet overlap dropped sharply with increasing age gap.Month to month dietary changes and year class differences were interpreted relative to benthic invertebrate abundance cycles. Months of increased diet overlap were characteristically those when favored prey types peaked, thereby simultaneously attracting several year classes to them. Hence increased diet. overlap is not necessarily an indicator of increased intraspecific competition.Habitat differences between the year classes of perch in Lake Opinicon were partial and concerned mainly the smaller, and larger, fish relative to those in the middle size range.     

The landscape genetics of yellow perch (Perca flavescens) in a large fluvial ecosystem

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.     

Growth- and feeding-related isotopic dilution and enrichment patterns in young-of-the-year yellow perch (Perca flavescens)

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.     

Effects of inhibitors on monoamine oxidase activity in perch (Perca flavescens) brain in vitro

1. Perch brain homogenates were incubated in vitro and monoamine oxidase (MAO) activity was determined fluorometrically, using a kynuramine substrate. 2. Clorgyline, harmaline and deprenyl inhibited MAO activity in a concentration-related manner, with single sigmoid inhibition curves, and the type A inhibitors harmaline and clorgyline were more effective than the type B inhibitor deprenyl. 3. Two types of inhibition were recognized in vitro; a fast-onsetting inhibition, similar to that produced by a reversible inhibitor, and a slow-onsetting inhibition, which is time- and concentration-dependent and presumably represents inactivation of the enzyme.     

Individual variation in the foraging strategies of young yellow perch (Perca flavescens) from the Ottawa River

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.