Use of Artificial Substrates to Estimate Prey Resources available to a Visually Feeding Benthivorous Fish

1990 ◽  
Vol 47 (4) ◽  
pp. 789-793 ◽  
Author(s):  
Blake R. Konkle ◽  
Nicholas C. Collins ◽  
Robert L. Baker
Keyword(s):  
Prey Availability ◽  
Lepomis Macrochirus ◽  
Stomach Contents ◽  
Artificial Substrates ◽  
Total Biomass ◽  
Benthivorous Fish ◽  
Taxonomic Range ◽  
Prey Resources ◽  
Lake Variation ◽  
Food Exploitation

Empirically derived estimates of prey resources using conventional sampling methods are generally poor indices of actual food available to visually feeding benthivorous fish. We preferentially sampled the most active fraction of the benthos (presumably that most detectable by fish) utilizing short-term (4 d) colonization of artificial substrates, and used colonist biomass to explain temporal variation in stomach contents of bluegill sunfish (Lepomis macrochirus) in Lake Opinicon, Ontario. Simple linear regressions showed that total biomass of colonists explained 75% of the variance in the biomass of stomach contents. Independent variables using a limited taxonomic range or size range of colonists explained less variance in stomach contents. The convenience and simplicity of this methodology, and its ability to explain within-lake variation in food exploitation by visual benthivores, suggest that artificial substrate colonization could be useful for surveys of prey availability to benthivorous fishes.

Patterns of Invertebrate Size and Abundance in Aquatic Habitats

1981 ◽  
Vol 38 (8) ◽  
pp. 896-904 ◽  
Author(s):  
Gary G. Mittelbach
Keyword(s):  
Body Size ◽  
Lognormal Distribution ◽  
Prey Size ◽  
Lepomis Macrochirus ◽  
Stomach Contents ◽  
Open Water ◽  
Total Biomass ◽  
Bare Sediment ◽  
Littoral Invertebrates

The size distributions of invertebrate prey found in the vegetation, bare sediment, and open water habitats of a small, Michigan lake were quantified for the months of May through August, 1979. The distribution of prey body size in each habitat generally conformed to a lognormal distribution, allowing a simple characterization of prey size and abundance in each habitat. Seasonally, the abundance of large littoral invertebrates declined markedly, shifting the distribution of prey size in the vegetation and bare sediment habitats towards smaller prey. The total biomass of vegetation-dwelling prey (exclusive of gastropods) also declined dramatically from May to August. These seasonal changes in prey size and abundance were correlated with a reduction in foraging intake for the dominant fish species in the lake, the bluegill sunfish (Lepomis macrochirus). Bluegills whose diet was > 80% vegetation prey showed a > 3-fold decline in stomach contents (prey weight/fish weight) from May to Ausut, during which time prey biomass in the vegetation declined 2.5-fold.Key words: body size, lognormal distribution, benthos, foraging, Lepomis, Michigan

scholarly journals Match–Mismatch Regulation for Bluegill and Yellow Perch Larvae and Their Prey in Sandhill Lakes

2010 ◽  
Vol 1 (2) ◽  
pp. 73-85 ◽  
Author(s):  
Jeffrey C. Jolley ◽  
David W. Willis ◽  
Richard S. Holland
Keyword(s):  
Yellow Perch ◽  
Prey Selection ◽  
Larval Fish ◽  
Lepomis Macrochirus ◽  
Perca Flavescens ◽  
Stomach Contents ◽  
Zooplankton Abundance ◽  
Growth And Survival ◽  
Fish Recruitment ◽  
Newly Hatched Larvae

Abstract Food availability may regulate fish recruitment, both directly and indirectly. The availability of zooplankton, especially to newly hatched larvae, is thought to be crucial to their early growth and survival. We examined stomach contents of larval bluegill Lepomis macrochirus and yellow perch Perca flavescens in Pelican Lake and Cameron Lake, Nebraska, in 2004 and 2005. We also determined zooplankton availability and calculated prey selection using Chesson's α. In addition, we investigated potential match–mismatch regulation of recruitment from 2004 to 2008. Bluegill positively selected copepod nauplii and Bosmina spp., and yellow perch often selected copepods. Abundant zooplankton populations were available for consumption. Matches of both larval bluegill and yellow perch abundance to zooplankton abundance were detected in all years; exact matches were common. Mismatches in predator and prey production were not observed. Predation by age-0 yellow perch on age-0 bluegill was not observed, even though yellow perch hatched 2 mo prior to bluegill. Given that zooplankton were abundant and well-timed to larval fish relative abundance over the time span of this study, the match–mismatch hypothesis alone may not fully account for observed recruitment variability in these populations. Environmental conditions may also affect recruitment and warrant further investigation.

Effect of water temperature on stomach evacuation rates, and estimation of daily food intake of bluegill sunfish (Lepomis macrochirus Rafinesque)

1990 ◽  
Vol 68 (3) ◽  
pp. 591-595 ◽  
Author(s):  
D. J. Booth
Keyword(s):  
Food Intake ◽  
Water Temperature ◽  
Field Experiments ◽  
Lepomis Macrochirus ◽  
Stomach Contents ◽  
Bluegill Sunfish ◽  
Field Methods ◽  
Daily Food Intake ◽  
Evacuation Rate ◽  
Daily Food

Field experiments were conducted over the summer of 1983 to determine food-evacuation rate and measure stomach fullness of bluegill sunfish (Lepomis macrochirus). A combination of these data gave estimates of daily food intake of fish. Fish were captured and held in large holding pens in Lake Opinicon, Ontario, Canada, and periodically subsampled over 24 h to monitor changes in mean weight of stomach contents. Stomach-evacuation rates obtained in this way increased significantly with water temperature over the range 10–25 °C. However, variation in stomach-evacuation rate was considerable, reducing the utility of water temperature as a predictor of stomach-evacuation rate. It is suggested that the simple field methods employed here to estimate stomach evacuation and food intake are more useful in the estimation of daily ration than the more commonly employed laboratory-based methods.

The diet of the emperor penguin, Aptenodytes forsteri, in Amanda Bay, Princess Elizabeth Land, Antarctica

1990 ◽  
Vol 2 (1) ◽  
pp. 23-28 ◽  
Author(s):  
N.J. Gales ◽  
N.T.W. Klages ◽  
R. Williams ◽  
E.J. Woehler
Keyword(s):  
Fish Species ◽  
Prey Availability ◽  
Stomach Contents ◽  
Emperor Penguin ◽  
Minor Components ◽  
Pleuragramma Antarcticum ◽  
Quantitative Studies ◽  
Emperor Penguins ◽  
Aptenodytes Forsteri ◽  
Local Topography

The diet of the emperor penguin Aptenodytes forsteri (Gray) in Amanda Bay, Princess Elizabeth Land, Antarctica, was studied by analysis of adult stomach contents during part of the chick-rearing period from August to October 1986. The penguins consumed almost entirely fish, mainly Pleuragramma antarcticum (Boulenger) (78% by number and 78% by mass). Other fish species, cephalopods and crustaceans were minor components. These results and those of the only other two, geographically distinct, quantitative studies of the diet of emperor penguins suggest that the diet of this species varies through the effects of local topography and hydrology on prey availability.

Community Response to Cumulative Toxic Impact: Effects of Acclimation on Zinc Tolerance of Aufwuchs

1992 ◽  
Vol 49 (10) ◽  
pp. 2155-2163 ◽  
Author(s):  
B. R. Niederlehner ◽  
John Cairns Jr.
Keyword(s):  
Second Generation ◽  
Community Response ◽  
Artificial Substrates ◽  
Community Respiration ◽  
Additional Stress ◽  
Total Biomass ◽  
Secondary Stress ◽  
Initial State ◽  
Zinc Tolerance ◽  
Zn Stress

Aufwuchs communities were developed on artificial substrates in a local pond. Second-generation communities were developed on identical substrates in laboratory systems receiving three levels of zinc (Zn): background, 73, and 172 μg∙L−1. After 21 d, second-generation communities were exposed to five concentrations of Zn ranging from background to 10 078 μg∙L−1 for 48 h. Protozoan communities developed under Zn stress were initially less rich taxonomically but subsequently lost fewer species in response to acute Zn exposures. Richness remaining after exposure to high Zn levels [Formula: see text] was similar for all groups. Taxonomic composition changed less in acclimated communities than in the control in response to secondary stress. Gross primary productivity was less impaired by secondary stress in communities acclimated to Zn. Community respiration, algal biomass, total biomass, respiration to biomass ratios, and ratios of soluble to total reactive phosphates did not differ in response to secondary stress. In general, communities developed under Zn stress were initially impaired but changed less in response to additional stress relative to their initial state.

Intrapopulation variation in the diet of franciscana dolphin (Pontoporia blainvillei) off southern Brazil

2021 ◽  
pp. 1-17
Author(s):  
Manuela Bassoi ◽  
Eduardo R. Secchi ◽  
Daniel Danilewicz ◽  
Ignacio B. Moreno ◽  
Roberta A. Santos ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Linear Models ◽  
Prey Species ◽  
Prey Availability ◽  
Prey Selection ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Brazilian Coast ◽  
Pontoporia Blainvillei ◽  
Franciscana Dolphin

Abstract The franciscana dolphin (Pontoporia blainvillei) is a coastal dolphin endemic to the western South Atlantic Ocean. The dolphin is listed as vulnerable in the IUCN Red List, with incidental catches in gillnet fisheries the greatest conservation concern for this species. Insights into the feeding habits of this dolphin are essential to understand its distribution, movements and use of habitat, which are fundamental for effective management of the species. The feeding habits of franciscana dolphins were investigated from analyses of stomach contents of animals incidentally caught by two fishing operations from southern and northern regions of the southern Brazilian coast. In this study we investigate the existence of intrapopulation (sexual maturity and sex-related) variation in the diet of the franciscana dolphin, evaluating the spatial (northern and southern geographic areas) and seasonal influences. The analyses were based on Linear and Generalized Linear Models (LM and GLM). The majority of identified prey species were bottom-dwelling teleosts and the squid Doryteuthis sanpaulensis. The most important prey differed spatially and seasonally between northern and southern regions of the study area, and our results revealed significant differences between sexes and sexual maturity stages, mainly related to prey species sizes. This variation might indicate differences in prey selection, availability or habitat use patterns among these groups. In any case, these dietary differences are likely to minimize intraspecific competition for food resources, and/or indicate spatio-temporal variation in prey availability.

Trophic ecology of a benthic intertidal hydroid, Tubularia crocea, at Mar del Plata, Argentina

2005 ◽  
Vol 85 (2) ◽  
pp. 307-312 ◽  
Author(s):  
Gabriel N. Genzano
Keyword(s):  
Trophic Ecology ◽  
Feeding Rate ◽  
Prey Availability ◽  
Stomach Contents ◽  
Dry Weight ◽  
Benthic Organisms ◽  
Food Items ◽  
The Mean ◽  
The Relationship ◽  
Prey Items

The trophic ecology and seasonal changes in the diet of the intertidal hydrozoan Tubularia crocea were studied analysing the enteron contents of hydranths collected each season of the year. The relationship between feeding rate, prey availability, and re-suspension processes caused by tidal currents was also assessed. The most prevalent food items were diatoms and crustaceans. The most remarkable differences occurred during summer, when crustaceans were more abundant than diatoms. Conversely, diatoms were the most abundant prey during other seasons, and they were almost the only prey found during winter. There was no relationship between abundances of primary prey items in the water column and their occurrences in stomach contents. Instead, most prey items consisted of benthic organisms, primarily two species of diatoms (Grammatophora marina and Licmophora abreviatta) and fragments (usually appendages) of the amphipods Caprella sp. and Jassa falcata. Most food items were digested within 4–4·5 hours. The mean number of items captured per polyp per day was determined to be 115·2±19·2 in summer, 93·6±14·4 in autumn, 76·8±21·6 in winter and 199·2±31·2 in spring. Prey biomass (dry weight) polyp−1 d−1 was 5·1 μg in summer, 2·3 μg in autumn, 1·8 μg in winter, and 6·3 μg in spring. These values, in relation to hydranth biomass (55·3 μg; dry weight), were equivalent to a food intake polyp−1 d−1 of 9·3%, 4·2%, 3·2% and 11·5% of its own weight, respectively.

Stable foraging areas and variable chick diet in Cassin's auklets (Ptychoramphus aleuticus) off southern California

2004 ◽  
Vol 82 (10) ◽  
pp. 1578-1595 ◽  
Author(s):  
Josh Adams ◽  
John Y Takekawa ◽  
Harry R Carter
Keyword(s):  
Southern California ◽  
Prey Availability ◽  
California Current ◽  
Breeding Ecology ◽  
Foraging Area ◽  
Cassin's Auklet ◽  
Prey Resources ◽  
Ptychoramphus Aleuticus ◽  
Second Clutch ◽  
Breeding Seasons

Planktivorous seabirds readily respond to changes in marine ecosystems and have the ability to integrate information regarding variability in abundance, availability, and community composition of key prey resources. We studied the foraging and breeding ecology of the Cassin's auklet, Ptychoramphus aleuticus (Pallas, 1811), off southern California during three breeding seasons (1999–2001), when large intra- and inter-annual variability occurred in local oceanographic conditions during a prolonged La Niña event. Radio-marked parents used consistent core foraging areas within 30 km of their colony, aggregated in shelf waters (<200 m depth), and occasionally foraged in deeper waters. Parents delivered primarily euphausiids, pelagic larval-juvenile fishes, and minor amounts of cephalopods and other crustaceans. Whereas the euphausiid Thysanoessa spinifera Holmes, 1900 was most important during 1999 and 2001, Euphausia pacifica Hansen, 1911 replaced adult T. spinifera in 2000 after an anomalous eastward inflection of the California Current occurred near the auklets' foraging area. Differences in chick diets, however, did not significantly influence fledging success and growth among first chicks, but the proportion of pairs successfully fledging an alpha chick and initiating a second clutch was exceptional in 1999 (63%) and 2000 (75%), and less in 2001 (7%). We suggest that dietary composition was influenced by modified prey availability driven in part by fluctuations in regional upwelling and circulation.

scholarly journals What makes Hemidactylus invasions successful? A case study on the island of Curaçao

2020 ◽  
Author(s):  
April D. Lamb ◽  
Catherine A. Lippi ◽  
Gregory J. Watkins-Colwell ◽  
Andrew Jones ◽  
Dan Warren ◽  
...  
Keyword(s):  
Urban Areas ◽  
Resource Competition ◽  
Food Resource ◽  
Stomach Contents ◽  
Western Hemisphere ◽  
Morphometric Analyses ◽  
Close Proximity ◽  
Reptile Species ◽  
Prey Resources ◽  
Hemidactylus Mabouia

AbstractHemidactylus spp. (House geckos) rank among the most successful invasive reptile species worldwide. Hemidactylus mabouia in particular has become ubiquitous across tropical urban settings in the Western Hemisphere. H. mabouia’s ability to thrive in close proximity to humans has led to the rapid displacement of native geckos in urban areas, however the mechanisms driving this displacement remain understudied. Here we combine data from nitrogen and carbon stable isotopes, stomach contents, and morphometric analyses of traits associated with feeding and locomotion to test alternate hypotheses of displacement between H. mabouia and a native gecko, Phyllodactylus martini, on the island of Curaçao. Consistent with expectations of direct food resource competition, we demonstrate substantial overlap of invertebrate prey resources between the species. Additionally, we found strong evidence from both diet content and stable isotope analyses that H. mabouia acts as a vertebrate predator, preying upon P. martini as well as other native and non-native reptiles. Finally, we show that H. mabouia possesses several morphological advantages, including larger sizes in feeding-associated traits and limb proportions that could offer a propulsive locomotor advantage on vertical surfaces. Together, these findings suggest the successful establishment of H. mabouia likely involves a combination of both exploitative interspecific competition and predation. Given the ubiquity of H. mabouia, illuminating the role of this species as both a competitor and a predator casts new concerns on the ecological and demographic impacts of this widespread urban invader.

scholarly journals Desert pumpkinseed: diet composition and breadth in a Moroccan river

2021 ◽  
pp. 34
Author(s):  
Christos Gkenas ◽  
Maria Filomena Magalhães ◽  
Nazaret Campos-Martin ◽  
Filipe Ribeiro ◽  
Miguel Clavero
Keyword(s):  
Arid Regions ◽  
Diet Composition ◽  
Prey Availability ◽  
Stomach Contents ◽  
Elevational Gradient ◽  
Diet Breadth ◽  
Lepomis Gibbosus ◽  
Feeding Plasticity ◽  
Generalist Diet ◽  
Widely Invasive

The widely invasive North American pumpkinseed sunfish, Lepomis gibbosus, is currently established in desert rivers in Morocco. The success of pumpkinseed in novel ecosystems has been associated with its generalist diet, but this trait remains unevaluated in arid regions. Desert rivers are harsh environments with limited water and prey availability which may adversely constrain the diet of fish. Here we studied the diet of pumpkinseed across 4 sites in the Draa River, embracing a 450 m elevational gradient covering from extremely dry lowlands to relatively humid highlands. We described pumpkinseed diet through the analysis of stomach contents of 82 individuals, collected in the fall of 2013. Pumpkinseed diet was dominated by Chironomidae in dry lowlands, while Ephemeroptera, Heteroptera, Trichoptera and Odonata were relevant prey in more humid highlands. Population diet breadth expanded with elevation, but individual specialization in diet was low among all sites. Our results highlight considerable changes in diet composition and breadth with aridity, suggesting that feeding plasticity and use of exclusive, locally abundant prey rather than generalized feeding may be associated with the success of pumpkinseed in most arid areas in desert rivers.

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