Boring sponge (Cliona celata)
Photo by Natasha Hurley-Walker
seen from United States

seen from Brazil
seen from United States
seen from United States

seen from United States

seen from Canada
seen from Canada

seen from United States
seen from Germany

seen from Canada

seen from Spain

seen from Netherlands

seen from United States
seen from Pakistan
seen from Sweden

seen from United States
seen from United Kingdom

seen from Türkiye
seen from Türkiye

seen from United States
Boring sponge (Cliona celata)
Photo by Natasha Hurley-Walker
Red Boring Sponge (Cliona celata)
...a species of demosponge that is found throughout the Atlantic, and is most common in New England. Like their common name suggests these sponges are often found bored into limestone or the shells of bivalves. Red boring sponges can reproduce both sexually and asexually and their larvae tend to seek out molluscs to attach onto. This usually results in death for the bivalve.
I also have no idea why they are called red...
Phylogeny
Animalia-Porifera-Demospongiae-Tetractinomorpha-Hadromerida-Clionaidae-Cloina-celata
Image Source(s)