Ecomorphological diet predictions: an assessment using inland silverside (Menidia beryllina) and longear sunfish (Lepomis megalotis) from Lake Texoma (original) (raw)
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Resource partitioning by Lake Tana barbs predicted from fish morphometrics and prey characteristics
Reviews in Fish Biology and Fisheries, 2000
We develop a food-fish model (FFM), whichquantitatively relates properties of aquaticfood types (size, shape, escape velocity,habitat, mechanical properties and chemicalquality) to feeding structures of cyprinidfish. The model is based on functionalmorphology and experiments on search, capture,selection, and internal processing of food byfish. The FFM shows which food properties aremost critical in feeding and how fish canoptimise coping with them. Relative food sizeimposes the highest demands, followed by preyvelocity, food habitat and mechanicalproperties. These overrule taxonomic affinitiesof food types. Highly demanding food types(large, fast prey, suspensions of plankton,benthic prey and mechanically tough items)impose incompatible morphological requirementson fish. We apply the FFM to the endemic Barbus species flock of Lake Tana (Ethiopia),since the structural diversity of its 14species reflects recent adaptations to trophicniches. We predict their potentials inutilising different food types by quantitativecomparisons of 35 parameters, measured for eachspecies, with the values for each foodspecialist derived from the FFM. These dietpredictions are tested against gut contentsfrom 4,711 fish, sampled over seasons andhabitats. Gut contents and predictions show agood overall fit. The value of the model isshown by its resolution in predicting resourcepartitioning among the barbs. For the 14 barbsa trophic hierarchy with six major trophicgroups is reconstructed which closely matchesthe predictions. Trophic specialists (> 65%by volume of a single food type) are alsostructurally specialised, whereas less extremeanatomical structures characterise trophicgeneralists, allowing them to switch betweenfeeding modes. Trophic generalists are bestdefined by behavioral flexibility, sincefeeding modes integrate both fish and foodcharacters. The FFM is of practical use inevaluating the role of morphological diversityin an ecosystem and enables the analysis oftrophic interactions in fish communities and ofthe cascading effects by environmental change.Such an approach can be instrumental in thedevelopment of management strategies forfisheries and in conservation of biodiversity.
Canadian Journal of Fisheries and Aquatic Sciences, 1994
We used multivariate analyses to examine which variables among the environmental and spatial components can best account for dietary variation in a freshwater fish, brook trout, Salvelinus fontinalis. The diet composition of brook trout was quantified in 37 lakes of the Laurentian Shield, Québec, Canada. Among the 25 measured environmental variables, fish species composition, sampling date, macrophyte abundance, and trout body length were the best predictors of diet composition. The total variation in diet composition was partitioned into four components: pure environmental 21.6%, pure spatial 23.2%, shared 19.9%, and unexplained 35.3%. A significant spatial trend in diet composition existed even after accounting for the main effects measured by the environmental variables. The two sets of spatial variables, when combined with the environmental descriptors, extracted different components of the dietary variation. The study allowed us to (1) highlight the role of spatial structure in...
Archives of Polish Fisheries, 2015
Factor and multiple regression analysis were used to extract the morphometric variables that contributed to feeding success in three small freshwater fishes. Of the first two factors, factor 1, showed high loading of gut weight (GW), length of the upper (UJ), and lower jaws (LJ) in mola, Amblypharyngodon mola (Hamilton), and GW and vertical mouth opening (VMO) in punti, Puntius ticto (Hamilton). In darikana, Esomus danricus (Hamilton), GW, horizontal mouth opening (HMO), and VMO were highly loaded on factor 2. Gut length (GL) was closely associated withGWof all three species. Subsequently, variables with high loading on factors 1 or 2 were subjected to multiple regression analysis to observe their effect on feeding success, consideringGWas the dependent variable and the extracted variables as the independent variable. In A. mola, HMO and GL influenced GW, whereas in P. ticto, only GL determined GW in the fish. In E. danricus, GL, VMO, and HMO exerted a low effect on GW. Exceptionall...
Feeding Ecology of Fishes -A Mini Review
Fishes constitute more than half of the vertebrates, inhabiting almost every aquatic habitat of the world and form an inexpensive source of vital nutrients. The depletion of fishery stocks as a result of anthropogenic interferences is evident worldwide and mandates an urgent need to address the cause before rate of loss exceeds the limit. This makes the assessment of various aspects of fish, especially their feeding ecology quite imperative for developing conservation and management strategies. Food forms a vital factor for fishes required chiefly for growth and reproduction in fishes and its qualitative or quantitative variation is influenced by various biotic and abiotic factors. Amongst the various attributes influencing fishes, food and feeding constitute a vital aspect that impacts the growth and general wellbeing of the fish. Feeding ecology of a fish is directly linked to its population dynamics and helps in understanding of various aspects of fish like habitat preference, competition, prey selectivity, energy transfer etc. Under this backdrop the current review was drafted to acquire knowledge about the three major aspects of feeding ecology of fish i.e., analysis of the gut contents, feeding biology and prey selectivity. The analysis of gut contents helps to identify the prey diversity and abundance consumed by a fish. Feeding biology helps to evaluate the acceptability of the prey by depicting the correlation between biology of the fish and its food preferences. Prey selectivity deals with the evaluation of prey choice depicting the reason behind choice of one prey over the other.