The devil crab: a misunderstood, velvety crustacean that transformed from pest to prized catch.

Nature · Published 3 October 2026 Swipe more like this →

In short: Known for its aggressive nature and striking red eyes, the velvet crab was once dismissed as a nuisance by British fishermen. Today, it is a culinary delicacy and a vital commercial resource, though its complex evolutionary history and fluctuating population numbers continue to challenge marine biologists and the fishing industry alike.

The velvet crab, Necora puber, is a distinctive crustacean defined by a dark, flattened carapace covered in short, yellowish hairs that create a soft, velvety texture. Reaching up to 10 cm in width and 250 grams in weight, this species is the largest swimming crab in British coastal waters. Its reputation as a 'devil crab' stems from its notoriously aggressive behavior, a trait that once led fishermen to view it as a pest rather than a product.

Taxonomically, the crab has had a turbulent history. First described by Carl Linnaeus in 1767, the original description was so vague that its identity remains contested. Over the centuries, it has been shuffled between various genera, including Portunus, Macropipus, and Liocarcinus. It was not until 1987 that Holthuis placed it in its own unique genus, Necora, named after a Galician term for the animal. Modern phylogenetic studies continue to debate its exact placement, with conflicting evidence from nuclear and mitochondrial DNA suggesting that morphological traits like carapace shape may be misleading due to convergent evolution.

The commercial rise of the velvet crab began in the 1980s, triggered by a collapse in southern European stocks. In France, mass mortality events between 1984 and 1988 saw catches plummet by 96%, likely due to Hematodinium infections. This crisis forced Ireland and Scotland to pivot, turning their bycatch into a major industry. Scotland is now Europe's largest producer, landing over two thousand tonnes worth £5.8 million in 2011. However, this success is fragile; recent declines in Irish catches and concerns over overfishing in areas like the Firth of Clyde highlight the ongoing struggle to balance economic demand with the biological reality of these complex, aggressive creatures.

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