Allocations to clonal replication in a marine scyphozoan (Aurelia)

Clonal plants and animals share life history traits that may make them more similar to each other than each is to its unitary counterparts. However, there is little empirical or theoretical research treating clonal plants and animals as a group of organisms to be compared to unitary organisms. One difficulty in creating a unified concept of clonal biology is that botanists and zoologists share a common vocabulary to discuss clonal organisms, but use many of the terms differently. I developed a glossary that both outlines definitions for terms that are used similarly by botanists and zoologists, and incorporates new terms that may resolve some of the ambiguities. I also addressed the ecological and evolutionary consequences of clonality that are common to plants and animals. The chapter on clonal biology grew out of my interest in the complex life cycles of marine cnidarians.; The life cycle of Aurelia comprises two body forms---a benthic, clonal polyp and a pelagic, sexual medusa. The clonal activities of scyphozoan polyps are budding (which produces additional polyps) and strobilation (which produces juvenile medusae). Little is known about the biology of scyphozoan polyps, and how their ecology relates to that of medusae. In this year-long experiment, I subjected a cohort of genetically identical Aurelia polyps to two feeding regimes that differed only in the frequency of food availability. As expected, frequently fed polyps had higher budding and strobilation rates than polyps fed infrequently. However, in addition to having lower overall rates of cloning than their frequently-fed clonemates, which produced ephyrae and buds in roughly equal numbers, polyps fed infrequently demonstrated a different pattern of clonal allocation, producing five times as many dispersive ephyrae as stationary buds. This pattern may indicate: (a) a strategy to minimize competition among benthic polyps when food is scarce; (b) an attempt to disperse the genotype from the benthos into the plankton, where conditions may be more favorable; or (c) an attempt to produce the sexual phase of the life cycle before the genet goes extinct.