HIPPOIDEA

'Hippoidea' is a superfamily of decapod crustaceans known as 'sand crabs' or 'mole crabs' ^[1].

Contents

Ecology

Classification

References

Ecology

Hippoids are adapted to burrowing into sandy beaches, a habit they share with raninid crabs, and the parallel evolution of the two groups is striking ^[2]. The whole body is almost ovoid, the first pereiopods have no claws, and the telson is long, all of which characters are not seen in related groups ^[3]. Unlike most other decapods, sand crabs cannot walk; instead they use their legs to dig into the sand ^[4]. Members of the family Hippidae beat their uropods to swim .
Apart from the polar regions, hippoids can be found throughout the world, although larvae of one species have been found in Antarctic waters, despite the lack of suitable sandy beaches in the Antarctic ^[5].

Classification

Alongside hermit crabs and allies (Paguroidea), squat lobsters and allies (Galatheoidea) and the hairy stone crab (''Lomis hirta'', Lomisoidea), Hippoidea is one of the four groups that make up the infraorder Anomura ^[6]. Of the four, Hippoidea is thought to be the most basal, with the other three groups being more closely related to each other than to Hippoidea ^[7].
The fossil record of sand crabs is sparse , but extends back to the Cretaceous period .
Sand crabs are placed in three families († represents exclusively fossil taxa) ^[8]:
'Albuneidae'

★ ''Albunea''

★ ''Austrolepidopa''

★ ''Harryhausenia''† ^[9]

★ ''Italialbunea''†

★ ''Leucolepidopa''

★ ''Lepidopa''

★ ''Paraleucolepidopa''

★ ''Paralbunea''

★ ''Praealbunea''† 

★ ''Squillalbunea''

★ ''Stemonopa''

★ ''Zygopa''
'Blepharipodidae'

★ ''Blepharipoda''

★ ''Lophomastix''


'Hippidae'

★ ''Emerita''

★ ''Hippa''

★ ''Mastigochirus''

★ ''Mastigopus''

References

1. Larval development in the sand crab, ''Emerita emeritus'' (L., 1767) (Anomura, Hippoidea) reared in the laboratory, Sunil Israel, T. Senthil Murugan, V. P. Venugopalan, T. Subramoniam, N. Munuswamy & G. van der Velde, , , Crustaceana, 2006
2. The first record of albuneid crabs (Crustacea, Decapoda) from the Cretaceous, R. H. B. Fraaije, , , Bulletin of the Mizunami Fossil Museum,
3. Key to Infraorder Anomura J. Maxwell, D. Cowles & H. Helmstetler
4. Digging in sand crabs (Decapoda, Anomura, Hippoidea): interleg coordination, Zen Faulkes & Dorothy H. Paul, , , Journal of Experimental Biology, 1997
5. First record of anomuran and brachyuran larvae (Crustacea: Decapoda) from Antarctic waters, Sven Thatje & Veronica Fuentes, , , Polar Biology, 2003
6. An Updated Classification of the Recent Crustacea, J. W. Martin & G. E. Davis, , , Natural History Museum of Los Angeles County, 2001,
7. Phylogenetic position of the freshwater anomuran family Aeglidae, Marcos Pérez-Losada, Carlos G. Jara, Georgina Bond-Buckup, Megan L. Porter & Keith A. Crandall, , , Journal of Crustacean Biology, 2002
8. A worldwide revision of the Recent and fossil sand crabs of the Albuneidae Stimpson and Blepharipodidae, new family (Crustacea, Decapoda, Anomura, Hippoidea), Christopher B. Boyko, , , Bulletin of the American Museum of Natural History, 2002
9. A new genus of fossil sand crab (Anomura: Albuneidae) from the Oligocene of Italy, Christopher B. Boyko, , , Palaeontology, 2004