ABSTRACT
Sponges are one of the major phyla found in the marine hard-substrate benthos, both with respect to the number of species and their biomass. Despite the ecological dominance of the sponges, especially Demospongiae, due to their diversity of form, structure, and physiological adaptation, most species are confined to relatively little or unpolluted areas. This chapter explains that under incubation conditions with polluted water, the exopolyphosphatase activity is inhibited in the sponge. It observes that the sponge Suberites domuncula also has a plasma membrane extrusion pump, a multixenobiotic resistance protein. The chapter demonstrates that the ubiquitin pathway exists in sponges. The receptor tyrosine kinase, another gene coding for an inducible and adaptive protein, was cloned from G. cydonium. The chapter concludes that changes in poly metabolism in sponge tissue, which can be measured by simple methods, may be a sensitive indicator of polluted environments.
