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Temporal range: Late Jurassic–Recent
Pylocheles miersii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Superfamily: Paguroidea
Family: Pylochelidae
Bate, 1888 [1]
Type genus
Pylocheles A. Milne-Edwards, 1880

Pomatochelidae T. R. R. Stebbing, 1914

The Pylochelidae are a family of hermit crabs. Its members are commonly called the 'symmetrical hermit crabs'.[2] They live in all the world's oceans, except the Arctic and the Antarctic,[2] at depths of 2,000 m (6,600 ft).[3] Due to their cryptic nature and relative scarcity, only around 60 specimens had been collected before 1987, when a monograph was published detailing a further 400.[4]


Unlike other hermit crabs, pylochelid hermit crabs are not markedly asymmetrical, with a straight body and equal numbers of appendages on both sides. This characteristic, together with the partial calcification of the abdomen (which is soft in other hermit crabs) led Edward J. Miers, when describing the first species, to consider it to represent a transition between hermit crabs and "Macrura" (long-tailed decapods, such as lobsters and shrimp).[5] Correspondingly, pylochelid hermit crabs do not usually inhabit gastropod shells, but instead withdraw into decayed pieces of wood, stones, tusk shells (especially Dentaliidae),[6] living sponges,[3] pieces of bamboo or mangroves.[6] Their claws are often adapted to form an operculum, which closes off the entrance to their home.[6]


Although the family as a whole has a global distribution, diversity is concentrated in the Indo-Pacific,[5] with only four species being found in the western Atlantic Ocean and Caribbean Sea (Cheiroplatea scutata, Pylocheles agassizii, Bathycheles cubensis and Mixtopagurus paradoxus). Pylochelid hermit crabs inhabit a great range in water depths, from 100 to 2,200 m (330 to 7,220 ft),[4] with most living between 200 and 500 m (660 and 1,640 ft) deep.[3]


The family contains 41 species in 10 genera:[7][8]


  1. ^ "Pylochelidae". Integrated Taxonomic Information System. Retrieved October 8, 2010. 
  2. ^ a b P. McLaughlin, S. Ahyong & J. K. Lowry (October 2, 2002). "Pylochelidae Bate, 1888". Anomura: Families. Australian Museum. 
  3. ^ a b c Jacques Forest (1987). "Ethology and Distribution of Pylochelidae (Crustacea Decapoda Coenobitoidea)". Bulletin of Marine Science. 41 (2): 309–321. 
  4. ^ a b Patsy A. McLaughlin & Rafael Lemaitre (2009). "A new classification for the Pylochelidae (Decapoda: Anomura: Paguroidea) and descriptions of new taxa" (PDF). Raffles Bulletin of Zoology. Suppl. 20: 159–231. 
  5. ^ a b Rafael Lemaitre, Patsy A. McLaughlin & Ulf Sorhannus (2009). "Phylogenetic relationships within the Pylochelidae (Decapoda: Anomura: Paguroidea): A cladistic analysis based on morphological characters" (PDF). Zootaxa. 2022: 1–14. 
  6. ^ a b c "Family PYLOCHELIDAE Bate, 1888". Australian Faunal Directory. Department of the Environment, Water, Heritage and the Arts. September 9, 2009. 
  7. ^ Patsy A. McLaughlin, Tomoyuki Komai, Rafael Lemaitre & Dwi Listyo Rahayu (2010). Martyn E. Y. Low; S. H. Tan, eds. "Annotated checklist of anomuran decapod crustaceans of the world (exclusive of the Kiwaoidea and families Chirostylidae and Galatheidae of the Galatheoidea)" (PDF). Zootaxa. Suppl. 23: 5–107.  |chapter= ignored (help)
  8. ^ René H.B. Fraaije, Adiël A. Klompmaker & Pedro Artal (2012). "New species, genera and a family of hermit crabs (Crustacea, Anomura, Paguroidea) from a mid-Cretaceous reef of Navarra, northern Spain". Neues Jahrbuch für Geologie und Paläontologie. 263 (1): 85–92. doi:10.1127/0077-7749/2012/0213. 

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