Cannibalism of newly-metamorphosed juvenile sea stars

Cannibalism is widespread across the animal kingdom, occurring in more than 1300 species of invertebrates and vertebrates across terrestrial and aquatic habitats (Fox, 1975; Polis, 1981; Elgar and Crespi, 1992). Cannibalism, defined as the consumption of all or part of a conspecific individual, can occur during multiple stages in the life cycle of an organism (Elgar and Crespi, 1992).  As such, cannibalism potentially affects animal behavior, life history strategies, population size and reproductive success (Cushing et al., 2015). Intra- and inter-specific competition, overcrowding, lack of food, or poor quality food are all stressors that induce cannibalistic behavior (Elgar et al., 1992). Cannibalistic individuals should even be selected for since those individuals would gain nutritional resources with high stoichiometric compatibility and face decreased intraspecific competition (MacArthur et al., 1966; Mitra & Flynn, 2005). Acquisition of high quality nutrients and reduced compe...同类相食在动物界中广泛分布，已在陆生与水生生境的1300余种无脊椎动物和脊椎动物类群中被记录（Fox, 1975; Polis, 1981; Elgar and Crespi, 1992）。同类相食被定义为取食同种个体的全部或部分躯体，可发生于生物体生命周期的多个阶段（Elgar and Crespi, 1992）。正因如此，同类相食可能对动物行为、生活史策略、种群规模与繁殖成功率造成影响（Cushing et al., 2015）。种内与种间竞争、种群过度拥挤、食物匮乏或食物质量低劣，均为诱发同类相食行为的胁迫因子（Elgar et al., 1992）。具备同类相食行为的个体理应受到自然选择的青睐，因为此类个体能够获取化学计量相容性较高的营养资源，并降低种内竞争压力（MacArthur et al., 1966; Mitra & Flynn, 2005）。获取优质营养与降低竞争……