Scuba Season

Barrel sponge

Xestospongia testudinaria

Sighting evidence at Black Rock Cook Islands, Rarotonga, Cook Islands

Barrel sponge

Photo: Albert Kok · CC BY-SA

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

0 records within 25 km

Confidence: low

No date on file
How is this calculated?

Sighting evidence is compiled from iNaturalist observation records within a set proximity radius, filtered for quality-grade observations. “Last confirmed” is the date of the most recent research-grade record. Record count covers a rolling 24-month window. Confidence reflects record count, recency, and consistency of seasonal signal.

Also seen at other sites