Barrel sponge
Xestospongia testudinaria
Sighting evidence at Black Rock Cook Islands, Rarotonga, Cook Islands
One of the largest invertebrates on coral reef walls, barrel sponges can grow for centuries and reach over 2 metres in diameter. They filter enormous volumes of seawater and are an important part of the reef's nutrient cycling. Large specimens at Black Rock serve as cleaning stations for turtles and small reef fish that pick parasites from their outer surfaces.
Evidence at this site
No confirmed records on file at this site
Barrel sponge is listed as a curated species here based on historical reports.