Active selection for large guppies, Poecilia reticulata, by the pike cichlid, Crenicicha saxatilis

Article Abstract:

Investigation was conducted to determine whether Crenicichla saxatilis is a size-selective predator, if the selectivity is a result of active choice and if the optimal prey size can be explained according to an optimal foraging model. The study confirms that Crenicichla saxatilis is a size-selective predator selecting large guppies, while earlier evidence for selectivity for large prey in Crenicichla cichlids was weak and equivocal.

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The relationship between wetland hydroperiod and nestedness patterns in assemblages of larval amphibians and predatory macroinvertibrates

Article Abstract:

Patterns of nestedness in assemblages of larval amphibians and predatory macroinvertibrates in 42 isolated freshwater wetlands in southern New Hampshire, USA were investigated. It was found that amphibians had a significantly lower degree of nestedness than macroinvertibrates, suggesting that a higher proportion of amphibian species found in species-poor assemblages was unlikely to occur in species-rich assemblages of amphibians.

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Timing an ontogenetic niche shift: reponses of emerging salmon alevins to chemical cues from predators and competitors

Article Abstract:

The responses of emerging Atlantic salmon (Salmo salar) alevins to chemical cues from two piscivorous fish predators and conspecific competitors are examined. The salmon alevins exhibit flexible ontogenetic niche shifts in the timing of emergence in response to predator cues.

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