INFLUENCE OF TEMPERATURE AND SALINITY ON LARVAL DEVELOPMENT OF BALANUS AMPHITRITE - IMPLICATIONS IN FOULING ECOLOGY

Recruitment of the barnacle Balanus amphitrite into a macrofouling community was examined in a semi-enclosed coastal environment (Hamana Bay, Japan), where water exchange with the adjacent open sea is very limited. The recruitment period of these barnacles was shorter than the period in which this species can breed and in which the cirripede larvae are present in the environment. Rearing of B, amphitrite larvae at different temperatures (15 to 30 degrees C) and salinities (10, 20 and 30%) revealed that its development is euryhaline. The influence of temperature was found to be greatest on the second instar. Mortality rates at 15 degrees C temperature ranged from 43% (30% salinity) to 99% (10% salinity). Rearing experiments indicated that larvae released to the environment during autumn and winter failed to establish themselves in the macrofouling community because of adverse environmental conditions. These results also show that loss of planktonic larvae through starvation and misrouting may well be the main cause of reproductive loss.