Velvet Swimming Crab

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Sighting evidence at Dunstaffnage Wall, Oban

Photo: Georgia · CC BY-NC

Velvet swimming crabs are the most aggressive crustacean in Scottish waters, raising their claws and facing divers directly when approached rather than retreating. Their paddle-shaped rear legs allow rapid bursts of swimming when threatened or hunting. Night dives at Dunstaffnage reveal these crabs actively pursuing prey across open substrate, their red eyes reflecting torch light from surprising distances.

Evidence at this site

6 records within 25 km

Confidence: medium

Last confirmed Jun 2026

Seasonality

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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.

Velvet Swimming Crab

Evidence at this site

Seasonality

Also seen at other sites