scubaseason

Flabellina Nudibranch

Flabellina affinis

Sighting evidence at Sponge Gardens, Djerba

These vivid purple and cerise nudibranchs appear in large numbers from March through June, grazing specifically on hydroids that colonise sponge surfaces during the spring plankton bloom. Their bright colouration functions as aposematic warning to fish predators, advertising the noxious compounds sequestered from their hydroid diet. Finding multiple individuals on a single large sponge is common in peak season.

Evidence at this site

No confirmed records on file at this site

Flabellina Nudibranch 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