The Caridea, commonly known as caridean shrimp or true shrimp, from the Greek word καρίς, καρίδος, are an infraorder of shrimp within the order Decapoda. This infraorder contains all species of true shrimp. They are found widely around the world in both fresh and salt water. Many other animals with similar names – such as the mud shrimp of Axiidea and the boxer shrimp of Stenopodidea – are not true shrimp, but many have evolved features similar to true shrimp.
The Decapoda or decapods are an order of crustaceans within the class Malacostraca, including many familiar groups, including crabs, lobsters, crayfish, shrimp, and prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 extant species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp and Anomura including hermit crabs, porcelain crabs, squat lobsters making up the bulk of the remainder. The earliest fossils of the group date to the Devonian.
The Stenopodidea or boxer shrimps are a small group of decapod crustaceans. Often confused with Caridea shrimp or Dendrobranchiata prawns, they are neither, belonging to their own group.
The family Oplophoridae is a taxon of pelagic shrimp and the only subtaxon of the superfamily Oplophoroidea. It contains the following genera:
Crangonidae is a family of shrimp, of the superfamily Crangonoidea, including the commercially important species Crangon crangon. Its type genus is Crangon. Crangonid shrimps' first pair of pereiopods have partially chelate claws that they use to capture their prey. They burrow shallowly into sediment on the sea floor, and feed on bivalves, crustaceans, polychaetes, and some small fish.
Physetocaris is a monotypic genus of caridean shrimp, containing a single species, Physetocaris microphthalma.
Alpheus is a genus of snapping shrimp of the family Alpheidae. This genus contains in excess of 330 species, making this the most species-rich genus of shrimp. Like other snapping shrimp, the claws of Alpheus are asymmetrical, with one of the claws enlarged for making a popping noise. Some species in the genus enter into symbiotic relationships with gobiid fishes, and others associate with sea anemones.
Palaemonidae is a family of shrimp in the order Decapoda. Many species are carnivores that eat small invertebrates, and can be found in any aquatic habitat except the deep sea. One significant genus is Macrobrachium, which contains commercially fished species. Others inhabit coral reefs, where they associate with certain invertebrates, such as sponges, cnidarians, mollusks, and echinoderms, as cleaner shrimps, parasites, or commensals. They generally feed on detritus, though some are carnivores and hunt tiny animals.
Palaemon is a genus of caridean shrimp in the family Palaemonidae.
The Pandaloidea are a superfamily of shrimp, comprising the large family Pandalidae and the much smaller Chlorotocellidae.
Heterocarpus is a genus of deep-sea shrimp, mainly of tropical areas all over the world.
Alpheoidea is a superfamily of shrimp. Species of shrimp in the superfamily Alpheoidea are drag swimmers, as opposed to lift swimmers.
Nematocarcinoidea is a superfamily of shrimp, comprising four families – Eugonatonotidae, Nematocarcinidae, Rhynchocinetidae and Xiphocarididae. They share the presence of strap-like epipods on at least the first three pairs of pereiopods, and a blunt molar process.
Campylonotoidea is a superfamily of shrimp, containing the two families Campylonotidae and Bathypalaemonellidae. Fenner A. Chace considered it to be the sister group to the much larger superfamily Palaemonoidea, with which it shares the absence of endopods on the pereiopods, and the fact that the first pereiopod is thinner than the second. Using molecular phylogenetics, Bracken et al. proposed that Campylonotoidea may be closer to Atyoidea. There are sixteen described species in 3 genera; no fossils are known.
Pandalus is a genus of shrimp in the family Pandalidae. Members of the genus are medium-sized and live on or near the seabed. Some species are the subject of commercial fisheries and are caught by trawling. One species, Pandalus montagui, lives in association with the reef-building polychaete worm, Sabellaria spinulosa.
Sicyonia is a genus of prawns, placed in its own family, Sicyoniidae. It differs from other prawns in that the last three pairs of its pleopods are uniramous, rather than biramous as seen in all other prawns.
Juxtastenopus spinulatus is a species of stenopodidean shrimp. It lives in the Red Sea, and across the Indian Ocean as far east as the Philippines. It is red or pink, up to 28 mm (1.1 in) long, with enlarged third pereiopods. Originally described in the genus Engystenopus, it is now placed in the monotypic genus Juxtastenopus, in the family Stenopodidae.
Marsupenaeus is a monotypic genus of prawn. It contains a single species, Marsupenaeus japonicus, known as the kuruma shrimp, kuruma prawn, or Japanese tiger prawn. It occurs naturally in bays and seas of the Indo-West Pacific, but has also reached the Mediterranean Sea as a Lessepsian migrant. It is one of the largest species of prawns, and is accordingly one of the most economically important species in the family.
Nematocarcinus tenuisrostris, or long-legged shrimp, is a species of shrimp known from the Indian and Pacific Oceans.
Pandalus lucidirimicola, the sparkling shrimp, is a species of caridean shrimp in the family Pandalidae.
