Key to Infraorder Anomura

Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata

Taken primarily from  Kozloff, 1987, 1996  p. 404 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)

An excellent alternate, up to date key can be found in Wicksten, 2009 page 197.
 
 
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Lower taxonomic level Main Page Alphabetic Index Systematic Index Glossary
1a  Body as a whole almost ovoid; leg 1 not chelate or subchelate; telson twice as long as wide; found only on exposed sandy beaches, burrowing just under the surface Superfamily Hippoidea: Family Hippidae
1b Body as a whole not ovoid; leg 1 chelate or subchelate; telson, if obvious, not twice as long as wide; generally in rocky or stony situations, on muddy bottoms, or living in permanent burrows in mud or muddy sand 2
2a Uropods present and constituting part of a well developed tail fan (even in the case of crablike species in which the abdomen is permanently folded against the underside of the thorax) (picture)(picture) 3
2b Uropods,  if present, not constituting part of a well developed tail fan 5
3a Body somewhat lobsterlike, the abdomen bent under itself but not folded tightly against the underside of the thorax 4
3b Body crablike, the abdomen permanently folded against the underside of the thorax Superfamily Galatheoidea: Family Porcellanidae
4a Telson bent under the abdomen; not likely to be found in situations shallower than 900 m Superfamily Galatheoidea: Family Chirostylidae
4b Telson not bent under the abdomen; found in shallow water, as well as at considerable depths (picture) Superfamily Galatheoidea: Family Galatheidae
5a Uropods present, hooklike, and with a rasplike area on each ramus; abdomen soft, unsegmented, not folded against the underside of the thorax, generally twisted (but sometimes straight); living in snail shells, worm tubes, or cavities in sponge masses 6
5b Uropods absent; abdomen either firm or soft, segmented or unsegmented, folded against the underside of the thorax, not twisted; not living in snail shells, worm tubes, or cavities in  sponge masses Superfamily Paguroidea: Family Lithodidae
6a Bases of third maxillipeds as close together as those of the first 2 pairs; both sexes with paired pleopods (male with 2 pairs, female with 1 pair); with 13 pairs of gills; chelipeds similar and nearly equal (includes 2 species of hermit crabs found subtidally) Superfamily Paguroidea: Family Diogenidae
6b Bases of third maxillipeds much more widely separated than those of the first 2 pairs; either without paired pleopods, or with paired pleopods only in the male; with 11 pairs of gills: chelipeds generally dissimilar and unequal 7
7a Male without paired pleopods; female with paired gonopores (all intertidal hermit crabs and most subtidal hermit crabs belong in this group) Superfamily Paguroidea: Family Paguridae
7b Male with paired first and second pleopods; female with a gonopore on the left side only (includes a rare hermit crab found in deep water) Superfamily Paguroidea: Family Parapaguridae


Taxonomic Levels Represented in this Key:
Superfamily Galatheoidea
 Family Porcellanidae
 Family Galatheidae
Superfamily Hippoidea
 Family Hippidae
Superfamily Paguroidea
 Family Diogenidae
 Family Lithodidae
 Family Paguridae



Page created by Janisse Maxwell, 7-2002
Edited by:  Dave Cowles 8-2002, 2006
Edited by Hans Helmstetler 10-2002