| Blue crab population size in the northern Gulf of Mexico is believed to be controlled by high levels of post-settlement mortality, rather than by larval supply. It has been suggested that intra-year class cannibalism is the dominant source of post-settlement mortality of early juvenile blue crabs, yet little has been done to test this hypothesis in the field. In this study, field and laboratory experiments demonstrated that the density of prey, the availability of alternate food and the threat of predation did not significantly influence cannibalistic interactions between early juvenile blue crabs. Mortality of first instars due to intra- and inter-cohort cannibalism occurred in all but two of the field and laboratory treatments. These data suggest that intra- and inter-cohort cannibalism are self-regulatory mechanisms that control early juvenile blue crab abundance. |
