ABSTRACT
Many studies have indicated the importance of substrate for bryozoan distribution (Hayward, 1978, Hayward & Ryland, 1978, Cook, 1981) Bryozoan occurrence is restricted in most cases to firm substrate. When we start to think about the substrate colonized by Bryozoa, boulders and algae probably first come into our mind. And in majority we are right. But there are exceptions. Lunulitiforms are the perfect example of such exceptionality (e.g. Cadée et al., 1989, Cook & Chimonides, 1994). Through their morphology and life history they adapted to live on soft sediment. Lunulitiforms are free-living bryozoans, which at the beginning of their growth need small sand particles to develop the colony. Reaching a certain stage of development they continue to live free in sediment interstices or on the surface of the sea floor (Cook & Chimonides, 1994). A striking example from the Arctic is the soft bottom ctenostomate bryozoan Alcyonidium disciforme Smitt, 1871, its distribution
being driven by the occurrence of substrate dominated by clay and mud (Kuklinski & Porter 2004). Both taxa have around shape. In general, the bryozoan’ morphotype is strongly related to nature of the habitat it occupies (Cook, 1981). Not much attention has been paid to bryozoan ecology in soft-bottom environment, except for the Lunulitiforms (some exceptional examples Cook, 1979, 1981, Cadée, 1987).
