Some observations in tetraclita squamosa rufotincta Pilsbry

Aspects of the biology of Tetraclita squamosa rufotincta Pilsbry were investigated. Although a tropical species, on the shores at Elat, Israel, its breeding is virtually restricted to the colder winter months. The causal factors are considered and the results of some experimental work relative to temperature control given. For a cirripede, T.s. rufotincta has a remarkably large 'egg' - unusual in a tropical or even warm-water species. The egg size is compared with that of other species and the survival value of large size considered; excess nutrients are carried over from the embryo to at least the first planktonic larva, and may aid survival in a relatively nutrient poor environment. The animals do not become sexually mature until the second year after their settlement. Growth takes place largély in the colder winter months and is seasonally separated from the period when gonadal tissue is developed.