Ontogenetic variation in the body stoichiometry of two fish species

摘要: One of the central questions ecological stoichiometry theory is to what extent animal species maintain constant elemental composition in their bodies. Although several recent studies demonstrate intraspecific variation composition, relatively little known about ontogenetic changes vertebrates, especially during early life stages. We studied and interspecific body two fish different orders; fathead minnow (Pimephales promelas) sheepshead (Cyprinodon variegatus), reared under controlled laboratory conditions. During ontogeny, we measured chemical bodies, including carbon (C), nitrogen (N), phosphorus (P), calcium (Ca), ribonucleic acid (RNA) contents. found that N RNA contents were high stages declined substantially development. In contrast, C C:N ratios low embryos, post-embryos larvae, increased remarkably thereafter. Concentrations some elements (e.g., Ca, P, Ca:P) did not exhibit consistent trends, but fluctuated dynamically between consecutive developmental both species. Specific growth rates correlated significantly with Analyses relative importance P pools at each stage revealed was a considerable pool post-embryos, while bone-associated dominant later Our results suggest bodies considerably ontogeny. Each has its own stoichiometric signature, timing, magnitude direction can vary taxa.