Velvet Swimming Crab Versatility

The velvet swimming crab (Necora puber) appears to have a very varied diet.

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It feeds on seaweed, as here, but is also a versatile predator.

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Prey includes barnacles, which this one was scraping from the rocks…

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…and a variety of crabs.  This velvet swimming crab had attacked and was starting to eat a small, recently-moulted (and therefore very vulnerable) shore crab (Carcinus maenas).

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The shore crab attacked on this occasion was larger and managed to escape, leaving a leg and claw behind as a ‘snack’ for the velvet swimming crab.

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Cannibalism is a possibility (see the tell-tale red eyes of the small crab being eaten) and…

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…small hermit crabs are further potential prey.  The entrance of the shell occupied by this hermit was clearly being chipped away by the velvet swimming crab.

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This crab was using a similarly patient approach on a painted top-shell to access the mollusc inhabitant.  I saw it gradually chipping away at the shell opening at the beginning of a dive and, still continuing, over thirty minutes later.

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This time, a bivalve mollusc (flame shell) was the victim.