Variability in the reproductive effort of the limpet, Cellana tramoserica.

The reproductive effort of the limpet, Cellana tramoserica was investigated in high, mid, and low intertidal areas of the rocky shore as well as in a subtidal population. The reproductive effort of individuals within a population was independent of age. There was, however, a noticeable difference among populations with respect to the relative amount of gonad material spawned per year. The individuals from the subtidal population had the greatest reproductive effort, spawning the equivalent of 101% of their somatic weight per year, while the low, mid and high intertidal populations spawned the equivalent of 66%, 20%, 51%, respectively.Experimental transplants showed that individuals from all three intertidal populations increased their reproductive effort to match that of subtidal individuals. It was unlikely, therefore, that the observed patterns were the result of genetic differences among the populations. The reproductive effort of the populations was also not correlated with the rate of mortality of the adults in the four populations. The observed differences could be explained by a combination of the availability of food and intraspecific competition. The flexibility in the reproductive pattern of Cellana is hypothesised to be a result of this species having a dispersive larval stage, which may result in selection for plasticity of reproductive allocation, depending upon the environmental conditions at the site of settlement and growth to adult size.