Seasonal variation in settlement and spiculation of sponge larvae

A settlement study, based in the Hauraki Gulf, Auckland, New Zealand, has revealed 3 different seasonal reproductive patterns among Demospongiae. Species which settled on our substrates can be divided into summer settlers, winter settlers, or all-year-round settlers. The composition of these groups is given, and the affinities and habitats of the constituent species are commented on. Variation in aspects of the spicule complement have been observed and discussed for three species: Mycale macilenta, Microciona coccinea and Ectyomyxilla kerguelensis.