Anomura: Families

P. McLaughlin, S. Ahyong & J.K. Lowry

Shannon Point Marine Center
Western Washington University
1900 Shannon Point Road, Anacortes
Washington 98221-9081B, USA
patsy@sos.net

Division of Invertebrate Zoology
Australian Museum
6 College Street, Sydney, NSW 2010, Australia
shanea@austmus.gov.au
jimlowry@crustacea.net

Introduction

The infraorder Anomura includes such familiar crustaceans as the hermit crabs and king crabs, as well as the less familiar squat lobsters, porcelain crabs and mole crabs. Although many anomurans are referred to as crabs, the Anomura does not include 'true' crabs - these are included in the infraorder Brachyura and readily distinguished by lacking distinct uropods, having a broader, operculiform maxilliped 3, and in usually having the last pair of legs well-developed . As with other decapods, anomurans have 5 pairs of legs, but differ from almost all other decapods in having the last pair of legs greatly reduced in size. The abdomen may be elongated (e.g. symmetrical hermit crabs), short and folded under the body (e.g. squat lobsters, porcelain crabs and king crabs), or tightly curved to fit into gastropod shells (e.g. hermit crabs).

The majority of anomurans live in temperate or tropical marine habitats, but species of the Aeglidae live in freshwater streams in South America and one species of hermit crab is known from freshwater in Vanuatu (McLaughlin & Murray, 1990).

Borradaile (1903) included the Thalassinidea (marine yabbies, ghost nippers, mud lobsters) in the Anomura, and this view was accepted for much of the twentieth century. Burkenroad (1963) excluded the Thalassinidea from the Anomura, and it is now regarded as a distinct infraorder (Poore, 1994). Phylogenetic relationships within the Anomura remain debated but most workers agree that Anomura is monophyletic (Scholtz & Richter, 1994, Schram, 2001). Williamson (1992) and Spears et al. (1992) suggested that the sponge crabs (Dromiacea) might belong to the Anomura rather than Brachyura. Following the most recent studies and general consensus, we do not regard the Dromiacea as anomurans.

According to Davie (2002), the Anomura comprises 14 families arrayed in 4 superfamilies: Coenobitoidea (Coenobitidae, Diogenidae, Lomisidae, Pylochelidae, Pylojaquesidae), Paguroidea (Lithodidae, Paguridae, Parapaguridae), Galatheoidea (Aeglidae, Chirostylidae, Galatheidae, Porcellanidae), and Hippoidea (Albuneidae, Hippidae). Martin & Davis (2001), following McLaughlin (1983a, b) recognised a fifth superfamily, Lomisoidea, for the Lomidae.

Monographs and Interactive Keys

Anomura Families
Aeglidae
Albuneidae
Chirostylidae
Coenobitidae
Diogenidae
Galatheidae
Hippidae
Lithodidae
Lomidae
Paguridae
Parapaguridae
Porcellanidae
Pylochelidae

Cite this publication as: McLaughlin, P., S. Ahyong & J.K. Lowry (2002 onwards). 'Anomura: Families.' Version: 2 October 2002. https://crustacea.net.