The Pleocyemata include the remaining groups, including "true shrimp".
The Dendrobranchiata consist of prawns, including many species colloquially referred to as "shrimp", such as the "white shrimp", Litopenaeus setiferus. DecapodaĪchelata (spiny lobsters, slipper lobsters)Īxiidea (mud shrimp, ghost shrimp, or burrowing shrimp)Ĭlassification within the order Decapoda depends on the structure of the gills and legs, and the way in which the larvae develop, giving rise to two suborders: Dendrobranchiata and Pleocyemata. The cladogram below results from analysis by Wolfe et al., 2019. High species diversification can be traced to the Jurassic and Cretacious periods, which coincides with the rise and spread of modern coral reefs, a key habitat for the decapods. The remaining group, called Pleocyemata, then diverged between the swimming shrimp groupings and the crawling/walking group called Reptantia, consisting of lobsters and crabs. Evolution ĭecapods originated in the Late Ordovician around 455 million years ago, with the Dendrobranchiata (prawns) being the first group to diverge. There is one final pair called uropods, which, with the telson, form the tail fan. There are five more pairs of appendages on the abdomen. The head has five pairs of appendages, including mouthparts, antennae, and antennules. In front of the pereiopods are three pairs of maxillipeds that function as feeding appendages. In many decapods, one pair of these "legs" has enlarged pincers, called chelae, with the legs being called chelipeds. They are the pereiopods, found on the last five thoracic segments. As the name Decapoda (from the Greek δέκα, deca-, "ten", and πούς / ποδός, -pod, "foot") implies, ten of these appendages are considered legs. Decapods can have as many as 38 appendages, arranged in one pair per body segment.
0 kommentar(er)
