MARKOW, T; WATTS, T; University of Arizona; University of Arizona: The coupling of growth, RNA and DNA content, and C:N:P stoichiometry in Drosophila

The growth rate hypothesis, that rapid growth is associated with high levels of phosphorus relative to nitrogen and high levels of RNA relative to DNA, was tested in three species of Drosophila characterized by different ecologies. Egg to adult development time in the oliphagous D. melanogaster is 10 days, in the mycophagous D. falleni it is 9 days, and the soil-breeding cactophilic D.mettleri requires 20 days. Larvae were sampled every 12 hours after hatching and their mass specific growth rates determined. Although the mass-specific growth rates different significantly among species, the overall pattern of elemental ratios and nucleic acid contents were consistent with the growth rate hypothesis. Growth was most rapid early in development, when P relative to N and RNA relative to DNA, were high.