Life history and its variation of an intertidal dal barnacle, Chthamalus challengeri Hoek (Preliminary report)

Abstract

Intra-populational variation of life history traits in Chthamalus challengeri was studied in an intertidal bed rock which has a gentle slope with smooth surfaces. Although the occurrence of adults was restricted in the high tide-zone, the barnacle settled on rock surfaces from MHWS to MLWS with various density. Settlement, growth, reproduction (percentage of brooding, adult size versus total egg weight etc.) and survival pattern of the barnacle were investigated in detail at four different tidal zone including no-adult zone. Although it is considered that these four sub-populations of barnacles were from same gene-pool, it became clear that each sub-population had a highly differential life history pattern. Furthermore, timing of settlement affected the growth, reproduction and survival pattern of the barnacle. Intra-populational variation of life history traits in Chthamalus challengeri is very complicated. Factors affecting the population dynamics are discussed on the basis of the results of field and laboratory experiments. The comparison of life history traits of four sub-populations were carried out in full consideration of their environment conditions, and the importance of life history variation is discussed.