Cannibalism in Crustaceans

AbstractCannibalism is widespread in animal taxa, but perhaps nowhere more so than in crustaceans. It receives considerable research attention because it structures populations, influences the management of economically important species, and affects species of conservation concern on both the endangered and invasive ends of the spectrum. Crustaceans are particularly likely to engage in cannibalism because they molt. Molting is an energetically expensive process, and cannibalism may provide critical nutrition, even in typically herbivorous species. In addition, molting is a dangerous process that puts individuals at risk, and molting creates distinct size classes, with smaller individuals experiencing greater risk of depredation. The occurrence of cannibalism in crustaceans is influenced by many environmental factors, including habitat type and complexity and the availability of refugia, the availability of alternative prey, and the size structure of populations. In addition, the occurrence of cannibalism may be influenced by genetics and kin selection. While all these factors have been found to influence cannibalism in a range of crustacean species, there is significant variation within and among species in the likelihood of cannibalism and which factors are most influential in any given group. Despite much research on the proximate causes of cannibalism in crustaceans, many avenues of research remain, including the genetics of cannibalism and the degree to which kin selection might influence the evolution of crustacean cannibalism.