SCUBA March 2022 Issue 123 | Page 19

An Inachus spider crab eats a painted goby while several other gobies pass watchfully by
Inachus spider crab with snakelocks anemone
firmly in the crab ’ s claws ! The stricken fish continued to arch its body in a frantic bid to escape , and almost wriggled free , with the crab having to shift its hold to the base of its victim ’ s tail . With the crab ’ s grip now rather precarious , I still thought the goby would complete its getaway , but the crab was made of sterner stuff . It held on and proceeded to gradually eat its catch from the tail downward while the unfortunate fish was still breathing . I did say it was gruesome .
As always , such a meal attracted potential scavengers but the small spider crab was perfectly capable of defending its prize . It used its long , slender legs to prod small hermit crabs away and evaded a larger one with a neat sidestep that a scrum half would be proud of . Several other painted gobies came very close to investigate ; the biologist in me feeling sure they were seeking free scraps of food rather than providing sympathy to their fallen comrade !
Inachus spider crabs are described as omnivorous and I had previously assumed they ate mainly seaweed and small
Inachus spider crab among red seaweed and sponges at Swanage Pier
encrusting organisms but those claws , which are quite large relative to their body size , are relatively powerful and have other uses .
Interestingly , the pieces of seaweed they use ( along with sponge fragments ) to ‘ decorate ’ themselves for camouflage form a backup food supply when times are hard . These small crabs are resourceful as well as surprisingly ferocious ! �
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