Nudibranch (Flabellina)

Flabellina exoptata

Sighting evidence at Osezaki, Izu Peninsula

Osezaki hosts over 100 nudibranch species, with flabellinids being among the most conspicuous as they graze on hydroids encrusting the volcanic substrate. Their vivid cerata serve dual purposes — sequestering stinging nematocysts from hydroid prey for their own defence while also advertising toxicity to would-be predators.

Evidence at this site

No confirmed records on file at this site

Nudibranch (Flabellina) 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.