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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°C) and salinities (10, 20 and 30%) revealed that its development is euryhaline. The ~nfluence of temperature was found to be greatest on the second instar. Mortality rates at 15°C temperature ranged from 43 % (30% salinity) to 99% (10%0 salinity). Rearlng 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 rnisrouting may well be the main cause of reproductive loss.

The daily growth rate at 30•Ž decreased more in larger flounder (88 and 176 g) than in smaller ones (4 and 16 g), and the higher catabolic rate at 30•Ž for larger flounder appeared in the relationship between feeding rate and growth rate. Therefore, the high energy expenditure for catabolism appears to reduce the energy available for growth of larger flounder at 30•Ž.

Mangrove benthic macro-invertebrate communities have access to various food sources. The food web in this system may not be based on homogenous mangrove detritus. In order to determine the contributions of mangrove leaf litter and microalgae to the benthic macro-invertebrate community, we analyzed carbon and nitrogen stable isotope ratios in primary producers (mangrove leaf litter, phytoplankton and microphytobenthos), particulate organic matter, sedimentary organic matter and benthic macro-invertebrates from 3 microhabitats (tidal creeks, inside forests and forest gaps) in a mangrove forest in Trang province, Thailand. The stable isotope values of particulate and sedimentary organic matter did not differ greatly between microhabitats, and values were relatively similar to mangrove leaf litter. Invertebrates from tidal creeks and inside forests also showed δ 13 C values similar to mangrove leaf litter, whereas invertebrate tissues from forest gaps were close to microphytobenthos δ 13 C values. Most invertebrates showed an enriched δ 15 N value compared to the local particulate and sedimentary organic matter. These results indicate that invertebrates utilize different food sources in different microhabitats; they utilized mainly mangrove detritus in the tidal creeks and inside forests, but mainly microphytobenthos in the forest gaps. Moreover, the invertebrate biomass was highest in the forest gaps. This is important new information supporting the view that the mangrove food web is actually a diverse combination of webs based on a variety of resources, including homogenous mangrove detritus.