Population dynamics of the acorn barnacles, Tetraclita squamosa and Tetraclita japonica (Cirripedia: Balanomorpha), in Hong Kong

Abstract

Tetraclita squamosa and Tetraclita japonica are common, intertidal barnacles. In Hong Kong, the population dynamics of the two species exhibited spatial and temporal variation on two semi-exposed shores. T. squamosa produced egg masses from May-June and annual settlement and recruitment occurred from June-July. In contrast, settlement and recruitment of T. japonica was sparse from March-May, but intensified in July-October. Mature gonads and egg masses were, however, only present from September-November, suggesting the larvae from the two settlement pulses originated from other locations as well as Hong Kong populations. Settlement intensity and post-recruitment mortality of the two species varied between sites, possibly due to spatial variation in free rock space, physical transport of larvae and abundance of food in the water column. © Springer-Verlag 2004.