Painted Top Shell Nudibranch

Polycera quadrilineata

Sighting evidence at Dalvík Wall, Eyjafjörður

This striking yellow-and-black nudibranch is among the most common aeolid species found on Icelandic lava walls, feeding on encrusting bryozoans that colonise the basalt. It is active year-round even in near-freezing water, demonstrating the cold-water adaptations common to Nordic nudibranchs. Dense colonies of its preferred bryozoan prey make the Dalvík Wall a reliable sighting location.

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.