Intraspecific variability and speciation in sponges

Abstract

Knowledge of intraspecific variability, geographic differentiation, and speciation in sponges is still tenuous. Until recently, even the definition of the sponge individual was debated. Burton (1949b) rejected the terms ‘colony’ and ‘growth’, and excluded the usual concept of an individual among animals. He tentatively proposed the following definition of the term ‘individual’ for sponges: “An aggregation of cells to form a functionally independent soma having no connection or at most an incipient connection only, with a similar, specifically identical, soma” (p. 913). The most recent definition is found in Borojević, Fry et al. (1968): “A mass of sponge substance bounded by a continuous pinacoderm.” They considered a larva also to be an individual, but noted