Biology · Invertebrates & Marine Biology

With reference to Freshwater sponges, consider the following statements: I. They are sessile multicellular animals belonging to the phylum Porifera and cannot be described as prokaryotic organisms. II. Some of them can accumulate or adsorb toxic metals, and are therefore studied for their biomonitoring potential. III. Freshwater forms constitute the overwhelming majority of sponge diversity, while marine forms are comparatively few. Which of the statements given above are correct?