Relative effects of maternal and juvenile food availability for a marine snail

The relative importance of maternal vs. juvenile food environment on juvenile performance is poorly understood, particularly for marine organisms. Here, we use a manipulative experiment to compare the influence of maternal and juvenile nutrition on early juvenile performance for a marine gastropod (Cominella virgata) with completely benthic development. Adult whelks adjusted growth and capsule volume to food availability, but there was no effect on the initial size or number of their hatchlings, which varied greatly within and among females. Although hatchling survivorship was also unaffected by maternal nutrition, juveniles fed lower food showed decreased survivorship. By contrast, growth of C. virgata hatchlings in the month after hatching was higher for hatchlings from high-food mothers, suggesting important carry-over effects of maternal nutrition on early juveniles, mediated by a trait other than offspring size. This maternal effect faded in the second month after hatching, as the hatchling environment became more important.