Phorbas tenacior, Blue sponge is one of the first organisms to colonize new wrecks or any submerged vertical surface not yet colonized by marine organisms. In this video we see it on a wreck about 30 meters deep. Probably this wreck is quite recent, perhaps sunk between the first and second world wars, has several colonies of sponges including the blue encrusting sponge, which seems to prefer vertical walls away from direct sunlight. Obviously we also see it next to other species of sponges of the genus Tedania and Verongia but if we look at the part of the prow the presence of Phorbas tenacior ...

Demosponges are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide (World Porifera Database). Sponges, contrary to what one might think at first sight, are very simple multicellular animal organisms very similar in shape and appearance to plant organisms. There are no apparatus in the sponges and there is no trace of a nervous system.

Phorbas tenacior (Topsent, 1925) is a sponge of the family Hymedesmiidae (Demospongiae), widespread in the Mediterranean sea. ...