CRITTER CONFIDENTIAL The hermits who make friends
Paul Naylor takes a close look at the relationships forged between the UK ’ s hermit crabs and other forms of marine life
When it comes to charismatic invertebrates exhibiting entertaining behaviour , hermit crabs are near the top of the league . I have spent many happy underwater hours watching them carefully assess a new mollusc shell for a possible ‘ house ’ move , squabble with each other over a particularly desirable residence ( even if it ’ s already occupied !) or clash with other animals over some tasty carrion .
You don ’ t have to observe them for long to get the impression that hermit crabs of the same species behave differently to one another . Indeed , scientific studies show hermit crabs are one of the many animals that have a demonstrable ‘ personality ’, where individuals have particular behavioural traits that are consistent over time . One of the most obvious examples is that some hermits are inherently bolder than others and reappear more quickly at their shell entrance after withdrawing when disturbed , the so-called ‘ startle response ’. If you want that perfect photograph of a hermit crab , look for a bold individual !
On top of their behaviour as individuals , hermit crabs have intriguing relationships with a range of other species . Some common hermit crabs ( Pagurus bernhardus ) for example , carry a parasitic anemone and a few even look overloaded
Main : Large anemone on a hermit crab at Babbacombe ; far from being ‘ parasitic ’ it may help deter predators such as cuttlefish
Above : Small hermit crab with a good-sized ‘ parasitic ’ anemone on the beautiful Fal estuary maerl
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