Spiny Starfish

Marthasterias glacialis

Sighting evidence at St David's Head, Wales (Pembrokeshire)

Spectacular multi-armed starfish up to 70 cm across patrol the rocky substrate at St David's Head, feeding on barnacles, mussels, and sea urchins. They are often found in aggregations around mussel beds, their slow predatory advance contrasting with the rapid escape response of prey species. Their rigid spines and vivid orange-pink colouration make them among the most visually arresting invertebrates on Welsh reefs.

Evidence at this site

17 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.

Spiny Starfish

Evidence at this site

Seasonality

Also seen at other sites