Tetraclita (Cirripedia, Thoracica) tests as an important habitat for intertidal isopods and other marine and semi-terrestrial fauna on tropical rocky shores

The barnacles Tetraclita singaporensis and T. squamosa have a thick test to protect the animals against the diverse environmental stress of the tropical intertidal zone and also against predation by muricid gastropods. After the death of the barnacle, however, the empty test is often taken over by other marine fauna as well as semi-terrestrial animals. The sphaeromatid isopod Dynamenella ptychura was the most abundant inhabitant in empty tests observed in Singapore and Malaysia. Ovigerous crustaceans were common. Gastropod specimens comprised almost entirely juveniles of common intertidal species, including those of the littorinids Littoraria articulata and L. strigata . Gastropod eggs and veligers, insect larvae, pupae and nymphs, and spider spiderlings and immatures were also present. The haminoeid gastropod Smaragdinella was the dominant animal colonizing barnacles in a succession experiment. Temperature was significantly lower inside the empty test than outside, by 0.2°C. Almost 40% of the barnacle tests remained attached to the substratum for more than four months after the death of the individuals.