Reproductive Biology, Taxonomy, and Aspects of Chemical Ecology of Latrunculiidae (Porifera).

Sexual reproduction has been observed for the first time within the widely distributed sponge family, the Latrunculiidae. Latrunculia magnifica Keller 1889 was studied mainly in the northern Red Sea in the Gulf of Eilat and the Gulf of Suez. The sponge is hermaphroditic and viviparous. The embryo develops to a large (mean 868 +/- 144 {mu}m, max. 1200 {mu}m) parenchymella larva. The period of reproduction lasts for several months, ceasing only during the winter. Like oocytes, sperm appear to develop from archeocytes, which is uncommon among sponges. The presence of brooded larvae in L. magnifica supports the position of Latrunculiidae within the order Poecilosclerida, subclass Ceractinomorpha, rather than within the Tetractinomorpha. The absence of a periflagellar sleeve from around the base of the choanocyte's flagellum lends further support to this idea. Nuclear magnetic resonance (NMR) analysis of secondary metabolites within the sponge and its nudibranch predator (Chromodoris quadricolor) confirms that both species contain the same latrunculin homologue (either A or B). The latter finding indicates the presence of a compound derived from the diet (i.e., sponge) within the nudibranch.