blue sea sponges (disidea fragilis) on the coastal cliffs in krimea, black sea

animal aquatic benthal benthos bentos biofouling biological biology black sea fauna bottom ecological ecology environment europe exoskeleton filtration filtrations fouling haliclona invertebrate invertebrates life marine nature organisms porifera saltwater sessile sponge sponges spongia ukraine under water undersea world wild wildlife seaside spong spongea