TYPES OF INTERACTIONS IN CONSORTIA OF BAIKALIAN SPONGES

Abstract

The composition of invertebrate communities inhabiting Baikalian sponges was studied. All the sponges examined were inhabited by invertebrates. Their number varied from 80 to 280 individuals per 100 cm3 of sponge, the biomass was found to be from 200 to 1020 mg per 100 cm3 of sponge. Twelve taxa: Turbellaria, Hirudinea, Nematoda, Oligochaeta, Polychaeta, Copepoda, Ostracoda, Isopoda, Amphipoda, Trichoptera, Chironomidae, Mollusca were found. There are two distinctive sets of species within the sponge consortia, which we designate as “specific” and “non-specific” ones. The latter differs in sponges sampled in different parts of the lake. The specific set consists of species, which are typical of all the sponge species sampled in different parts of the lake. The interaction between the sponges and the inhabiting invertebrates includes topic and trophic links. For most of sponge-dwelling invertebrates their interaction with the sponge is most likely to be as proto-cooperation (nonobligate co-existence), and for some species like Brandtia parasitica and Acanthocyclops spongicola as mutualism (obligate co-existence).