Hermit crabs
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Hermit Crab |
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| Paguroidea | ||||||||||||
| Latreille , 1802 | ||||||||||||
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The six taxa of the hermit crabs belong together with the crab-shaped representatives of the king crabs and Hapalogastridae to the zoological superfamily Paguroidea. What the hermit crabs have in common is that they hide their abdomen in empty snail shells or similar dwellings formed by other living things, such as corals or chalky worm tubes. This behavior is vital for them, as their abdomen is soft and unprotected and could serve as a point of attack for predators. In the course of growth, larger and larger housings are required for replacement. King crabs have lost this way of life in the course of evolution and secondarily developed a largely highly calcified abdomen.
features
As decapods, hermit crabs have five pairs of limbs: a pair of scissor legs, two pairs of walking legs that protrude from the snail shell, and two pairs of smaller legs, shortened for their special function, with which they hold the snail shell in place. The families of the left-handed hermit crabs (Diogenidae) and the right-handed hermit crabs (Paguridae) differ in the side on which they carry the larger scissor bone, with the help of which they can close the entrance to their housing. The deep-sea hermit crabs (Parapaguridae) are considered "symmetrical hermit crabs" because their claws are the same size.
Way of life
There are also sessile paguroids, for example representatives of the genus Paguritta , which live in hard corals of the genus Porites and catch plankton with their antennae which have been converted into fishing nets . The terrestrial hermit crabs (Coenobitidae), known for example as the palm thief , spend their entire life on land , except for the larval stage . They only go into the water to fill their gill chambers with water, and the females also to release the larvae there after hatching. The palm thief already mentioned, however, only has rudimentary gills and no longer wears any protection in the adult stage.
A species of land hermit crabs
swell
- Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong et al .: A classification of living and fossil genera of decapod crustaceans . In: Raffles Bulletin of Zoology . Supplement No. 21. 2009, p. 1–109 ( pdf 7.73Mb [accessed March 11, 2012]).
- Jonas Keiler, Christian S. Wirkner, Stefan Richter: One hundred years of carcinization - the evolution of the crab-like habitus in Anomura (Arthropoda: Crustacea) . In: Biological Journal of the Linnean Society . 121. 2017, p. 200-222 ( [1] ).
