Portunoidea
| Portunoidea | |
|---|---|
| |
| Portumnus latipesof thePortunidae | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Subsection: | Heterotremata |
| Superfamily: | Portunoidea Rafinesque,1815 |
| Families[1] | |
|
7 extant and 4 extinct families: see text | |
Portunoideais asuperfamilyofcrabsthat includes the familyPortunidae,the swimming crabs. Which other crab families are also placed here is a matter of some contention, and may be revised followingmolecular phylogeneticanalyses.[1]
Description
[edit]Their rather flat and smoothcarapaceis usually wider than long and ofhexagonal,subhexagonal,rectangular,or transverselyovateshape. It is usually widest between the hindmost spines of the forward rim; there may be up to 9 pairs of these spines, with a few smaller ones right above the head, but they are missing altogether in somespecies.[2]
In some, the firstmaxilliped'sendopodis lobed, forming the characteristicportunid lobe.Thechelipedsare usually robust, and in some the lastpereiopodpair has ovatedactyls.Thesuturesof thesternumbetween segments 4 to 8 are usually incomplete, and in thePortunidae,the eighthsterniteis usually visible if seen from below and has apenialgroove.[2]
In males, theabdominalsomitesare either all free or the third to fifth are fused, often retaining the sutures though. The firstgonopodis strongly curved, with a swollen and strongly hooked base.[2]
Classification
[edit]
Portunoidea are close relatives of theXanthoidea,[2]and thefamiliesHexapodidaeandMathildellidae,usually included there, are sometimes placed in the Portunoidea, while the deep-sea crabs (Geryonidae) are usually placed in the Portunoidea but sometimes in the Xanthoidea. All Portunoidea live in theocean,although the familyTrichodactylidae,sometimes included here, live infresh water.
According to the latest synopsis, there are eleven families in the superfamily Portunoidea, four of which are extinct:[1]
- Carcinidae
- Carcineretidae(extinct)
- Catoptridae
- Geryonidae
- Lithophylacidae(extinct)
- Longusorbiidae(extinct)
- Macropipidae
- Pirimelidae
- Portunidae
- Psammocarcinidae(extinct)
- Thiidae
References
[edit]- ^abcSammy De Grave; N. Dean Pentcheff; Shane T. Ahyong; et al. (2009)."A classification of living and fossil genera of decapod crustaceans"(PDF).Raffles Bulletin of Zoology.Suppl. 21: 1–109.
- ^abcdHiroaki Karasawa & Carrie E. Schweitzer (2006)."A new classification of the Xanthoideasensu lato(Crustacea: Decapoda: Brachyura) based on phylogenetic analysis and traditional systematics and evaluation of all fossil Xanthoideasensu lato".Contributions to Zoology.75(1/2): 23–73.doi:10.1163/18759866-0750102002.Archived fromthe originalon 2016-03-03.Retrieved2008-11-23.
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