Paul Naylor offers a guide to some of our smaller critters – the various types of small hermit crab
UKDIVING CRITTERCONFIDENTIAL
South claw stance
Paul Naylor offers a guide to some of our smaller critters – the various types of small hermit crab
Pre-mate pair of South-claw hermit crabs
In the same way that the tompot blenny might win a ‘ pound for pound ’ feistiness prize among the fish , the ‘ south-claw ’ hermit crab qualifies for the same award in the crustacean category .
This charismatic little crab , usually less than 2cm long even with its shell
16 home , will only be familiar to divers and snorkellers who spend time over shallow sandy seabeds and seagrass meadows in the south and west of the UK . In the right habitat they can be abundant and some of my encounters with them have been surprisingly entertaining . When
Hairy hermit crab dwarfed by seaweed and seagrass fragments and the ‘ Parasitic ’ anemone it is carrying approaching a pair or a small group of them , they have not always withdrawn into their shells or burrowed into the sand as expected , but have simply carried on fighting with one another . On one occasion , they were so busy squabbling over a dead mollusc that they did not have time to eat it , despite there being more than enough food to go around !
The crab ’ s scientific name is Diogenes pugilator and I previously hoped that the second part , meaning ‘ boxer ’, arose from this pugnacious nature . Sadly , a more likely explanation is that the crab ’ s left-hand claw held across their shell entrance makes it resemble a clenched fist . The ‘ south-claw ’ common name comes from the way that the left-hand claw is dominant and much bigger than the right-hand one , unlike in other hermit crabs where claws are of similar size or the right is larger .
Many of the other and less easy to identify small hermit crabs found will be youngsters of the common hermit crab ( Pagurus bernhardus ), with the same colouration and prominent bumps on their claws as the larger adults . On a sandy seabed these little crabs can be very eager to clamber up