| Thalassinidea | |
|---|---|
| Upogebia deltaura | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Crustacea |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Thalassinidea Latreille, 1831 |
| Superfamilies and Families | |
|
|
Thalassinidea is an infraorder of decapod crustaceans that live in burrows in muddy bottoms of the world's oceans. In Australian English, the littoral thalassinidean Trypaea australiensis is referred to as the yabby[1] (a term which also refers to freshwater crayfish of the genus Cherax), frequently used as bait for estuarine fishing; elsewhere, however, they are poorly known, and as such have few vernacular names, "mud lobster" and "ghost shrimp" counting among them.
Recent molecular analyses have shown this group to be most closely related to Brachyura (crabs) and Anomura (hermit crabs and their allies). The fossil record of thalassinideans reaches back to the late Jurassic.[2]
The monophyly of the group is not certain; recent studies have suggested dividing the group into two infraorders, Gebiidea and Axiidea.[3]
There are believed to be 556 extant species of thalassinideans in 96 genera,[4] with the greatest diversity in the tropics, although with some species reaching latitudes above 60° north. About 95% of species live in shallow water, with only three taxa living below 2,000 metres (6,600 ft).[5]