scubaseason

Giant barrel sponge

Xestospongia muta

Sighting evidence at Le Cap, Martinique

Giant barrel sponges are the largest sponge species in the Caribbean and among the longest-lived animals on coral reefs, with some individuals estimated to be over 2000 years old based on growth rate studies. A single large barrel sponge can filter more than 90 litres of water per minute, extracting bacteria and dissolved organic matter — making them a critical water-quality mechanism on healthy reefs. They provide habitat for shrimps, small gobies, and occasional hawksbill turtles that feed on them. Their populations are considered a reef health indicator: dense barrel sponge assemblages like those at Le Cap indicate a nutrient-rich, productive system.

Evidence at this site

No confirmed records on file at this site

Giant barrel sponge is listed as a curated species here based on historical reports.

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