Recruitment Dynamics and Size Structure in Experimental Populations of the Mosquitofish, Gambusia affinis
Experimental populations of the cannibalistic livebearer, Gambusia affinis, were exposed to varying degrees of shelter for juveniles vulnerable to cannibalism by adults. High densities of shelter significantly reduced the effects of cannibalism and effectively maintained reproducing populations throughout the experiment (380 days). Population densities continuously declined in medium and low refuge density treatments due to a lack of recruitment. The size distributions of fish in these treatments narrowed with time, although the rate at which this occurred was greater in the low refuge density treatment.Abstract
Mean density (± SE) of mosquitofish (number · L−1) in the three refuge treatments over the duration of the experiment
Length frequency distributions of mosquitofish (percent composition of seven size classes) in the six aquaria over the duration of the experiment; A and B refer to the two replicates