Bigger is not always better : offspring size does not predict growth or survival for seven ascidian species
MetadataShow full item record
The presumed trade-off between offspring size and quality predicted by life history theory is often invoked to explain the wide range of propagule sizes observed in animals and plants. This trade-off is broadly supported by intraspecific studies but has been difficult to test in an interspecific context, particularly in animals. We tested the fitness consequences of offspring size both intra- and interspecifically for seven species of ascidians (sessile, suspension-feeding, marine invertebrates) whose offspring volumes varied over three orders of magnitude. We measured two major components of fitness, juvenile growth rates and survival, in laboratory and field experiments encompassing several food conditions. Contrary to the predictions of life history theory, larger offspring size did not result in higher rates of growth or survival, and large offspring did not perform better under nutritional stress, either intraspecifically or interspecifically. In fact, two of the four species with small offspring grew rapidly enough to catch up in size to the species with large offspring in as little as eight weeks, under wild-type food conditions. Trade-offs between growth potential and defense may overwhelm and obscure any trade-offs between offspring size and survival or growth rate. While large initial size may still confer a competitive advantage, we failed to detect any consequences of interspecific variation in initial size. This implies that larger offspring in these species, far from being inherently superior in growth or survival, require compensation in other aspects of life history if reproductive effort is to be efficient. Our results suggest that the importance of initial offspring size is context dependent and often overestimated relative to other life history traits.
Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 91 (2010): 3598–3608, doi:10.1890/09-2072.1.
Showing items related by title, author, creator and subject.
Effects of dissolved sulfide, pH, and temperature on growth and survival of marine hyperthermophilic archaea Lloyd, Karen G.; Edgcomb, Virginia P.; Molyneaux, Stephen J.; Boer, Simone; Wirsen, Carl O.; Atkins, Michael S.; Teske, Andreas (American Society for Microbiology, 2005-10)The ability of metabolically diverse hyperthermophilic archaea to withstand high temperatures, low pHs, high sulfide concentrations, and the absence of carbon and energy sources was investigated. Close relatives of our ...
Effect of habitat, origin, and herbivory on the survival and growth of recruit-sized S. polycystum fronds from MPAs and non-MPAs when reciprocally transplanted Hay, MarkRaw data on the survival of recruit-sized rammets of Sargassum polycystum originated from marine protected and non-protected areas (MPAs and non-MPAs, respectively) in Fiji, reciprocally transplanted between these areas ...
Hay, MarkRaw data on the growth of mature Sargassum polycystum fronds transplanted into or outside Sargassum beds, crowded and isolated conditions respectively, in a non-protected area in Fiji. Growth was obtained using the initial ...