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Hermit Crab

Hermit Crab ©Alex Mustard/2020VISION

Hermit crab

Enw gwyddonol: Pagurus bernhardus
If you spot a crawling shell next time you're at the seaside, take a closer look… it might be a hermit crab!

Species information

Ystadegau

Length of body: 3.5cm

Statws cadwraethol

Common

Pryd i'w gweld

January to December

Ynghylch

Hermit crabs live inside empty sea snail shells, particularly those of whelks and periwinkles. They can be found on rocky shores and down to depths of 150m. Hermit crabs are opportunistic scavengers, feeding on anything they can find. They have tough pincers but a soft body which they coil up inside their borrowed shell, using their hooked tail to help them to grip on. As they grow, hermit crabs move into ever larger shells.

Sut i'w hadnabod

The common hermit crab is the largest of several species of very similar hermit crabs and is often found in rockpools. Their body is reddish brown and right-hand pincer is larger than left. They are often found in periwinkle or whelk shells.

Dosbarthiad

Found around all UK coasts.

Cynefinoedd

Roeddech chi yn gwybod?

When two hermit crabs meet, one may attempt to steal the other's shell by forcibly evicting the current owner. The aggressor will knock on the shell it wants, drawing out the owner and fighting it out until one emerges victorious.

Sut y gall bobl helpu

When rockpooling, be careful to leave everything as you found it - replace any rocks you turn over, put back any crabs or fish and ensure not to scrape anything off its rocky home.