Thalassinidea is a former infraorder of decapod

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s that live in

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of s ...

s in muddy bottoms of the world's oceans. In

Australian English Australian English (AusE, AusEng, AuE, AuEng, en-AU) is the set of varieties of the English language native to Australia. It is the country's common language and ''de facto'' national language; while Australia has no official language, Eng ...

, the littoral thalassinidean ''

Trypaea australiensis The Australian ghost shrimp, marine yabby, or ghost nipper (''Trypaea australiensis'') is a species of ghost shrimp in the family Callianassidae, found in Australia and the Indo-West Pacific The Indo-Pacific is a vast biogeographic regio ...

'' is referred to as the ''yabby'' (a term which also refers to freshwater

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

of the genus ''

Cherax ''Cherax'', commonly known as yabby/yabbies in Australia, is the most widespread genus of fully aquatic crayfish in the Southern Hemisphere. Various species of cherax may be found in both still and flowing bodies of freshwater across most of ...

''), frequently used as bait for estuarine fishing; elsewhere, however, they are poorly known, and as such have few

vernacular A vernacular or vernacular language is in contrast with a "standard language". It refers to the language or dialect that is spoken by people that are inhabiting a particular country or region. The vernacular is typically the native language, n ...

names, "mud lobster" and "ghost shrimp" counting among them. The burrows made by thalassinideans are frequently preserved, and the fossil record of thalassinideans reaches back to the late Jurassic. The group was abandoned when it became clear that it represented two separate lineages, now both recognised as infraorders:

Gebiidea Gebiidea is an infraorder of decapod crustaceans. Gebiidea and Axiidea are divergent infraoders of the former infraorder Thalassinidea. These infraorders have converged ecologically and morphologically as burrowing forms.Dworschak, Peter C. (2 ...

and

Axiidea Axiidea is an infraorder of decapod crustaceans. They are colloquially known as mud shrimp, ghost shrimp, or burrowing shrimp; however, these decapods are only distantly related to true shrimp. Axiidea and Gebiidea are divergent infraoders of ...

. Recent molecular analyses have shown that thalassinideans are most closely related to Brachyura (

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s) and

Anomura Anomura (sometimes Anomala) is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans include the word ''crab'', all true crabs are in the sister group to the Anomura, the Brachyura (the two grou ...

( hermit crabs and their allies). There are believed to be 556 extant species of thalassinideans in 96 genera, with the greatest diversity in the tropics, although with some species reaching

latitude In geography, latitude is a coordinate that specifies the north–south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pole ...

s above 60° north. About 95% of species live in shallow water, with only three taxa living below .

References

Arthropod infraorders Obsolete arthropod taxa

See also

References