Decapoda in the context of "Cleaner shrimp"

Lobsters are malacostracan decapod crustaceans of the family Nephropidae or its synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in the coastal areas they populate.

Commercially important species include two species of Homarus from the northern Atlantic Ocean and scampi (which look more like a shrimp, or a "mini lobster")—the Northern Hemisphere genus Nephrops and the Southern Hemisphere genus Metanephrops.

Rhizocephala are derived barnacles that are parasitic castrators. Their hosts are mostly decapod crustaceans, but include Peracarida, mantis shrimps and thoracican barnacles. Their habitats range from the deep ocean to freshwater. Together with their sister groups Thoracica and Acrothoracica, they make up the subclass Cirripedia. Their body plan is uniquely reduced in an extreme adaptation to their parasitic lifestyle, and makes their relationship to other barnacles unrecognisable in the adult form. They also exhibit the most extreme sexual dimorphism of all known animals. The females are parasites who inject themselves into a host and take over their bodies through a network of filaments, while the males are hyperparasites who inject themselves into a settled female and cease to exist as independent organisms through the degeneration of all tissues except the ones responsible for spermatogenesis. The name Rhizocephala derives from the Ancient Greek roots ῥίζα (rhiza, "root") and κεφαλή (kephalē, "head"), describing the adult female, which mostly consists of a network of thread-like extensions penetrating the body of the host.

Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (members of the order of decapods), some of which are edible.

The term prawn is used particularly in the United Kingdom, Ireland, and Commonwealth nations, for large swimming crustaceans or shrimp, especially those with commercial significance in the fishing industry. Shrimp in this category often belong to the suborder Dendrobranchiata. In North America, the term is used less frequently, typically for freshwater shrimp. The terms shrimp and prawn themselves lack scientific standing. Over the years, the way they are used has changed, and in contemporary usage, the terms are almost interchangeable.

The Caridea, commonly known as caridean shrimp or true shrimp, from Ancient Greek καρίς, καρίδος (karís, karídos, "shrimp"), 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.

Dendrobranchiata is a suborder of decapods, commonly known as prawns (though this may be ambiguous). There are 540 extant species in seven families, and a fossil record extending back to the Devonian. They differ from related animals, such as Caridea and Stenopodidea, by the branching form of the gills (hence their scientific name Dendrobrachiata) and by the fact that they do not brood their eggs, but release them directly into the water. They may reach a length of over 330 millimetres (13 in) and a mass of 450 grams (1.0 lb), and are widely fished and farmed for human consumption.

Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged gastropod shells to protect their fragile abdomens. There are over 800 species of hermit crab, most of which possess an asymmetric abdomen concealed by a snug-fitting shell. Hermit crabs' soft (non-calcified) abdominal exoskeleton means they must occupy shelter produced by other organisms or risk being defenseless.

The strong association between hermit crabs and their shelters has significantly influenced their biology. Almost 800 species carry mobile shelters (most often calcified snail shells); this protective mobility contributes to the diversity and multitude of these crustaceans which are found in almost all marine environments. In most species, development involves metamorphosis from symmetric, free-swimming larvae to morphologically asymmetric, benthic-dwelling, shell-seeking crabs. Such physiological and behavioral extremes facilitate a transition to a sheltered lifestyle, revealing the extensive evolutionary lengths that led to the superfamily's success.

Shrimps and prawns are types of shellfish seafood that are consumed worldwide. Prawns and shrimps are crustacea and are very similar in appearance with the terms often used interchangeably in commercial farming and wild fisheries. A 1990s distinction made in Indian aquaculture literature, which increasingly uses the term "prawn" only for the freshwater forms of palaemonids and "shrimp" for the marine penaeids that belong to different suborders of Decapoda. This has not been universally accepted.

In the United Kingdom, the word "prawn" is more common on menus than "shrimp", whereas the opposite is the case in North America. Also, the term "prawn" is loosely used for larger types, especially those that come 30 (or fewer) to the kilogram — such as "king prawns", yet sometimes known as "jumbo shrimp". In Britain, very small crustaceans with a brownish shell are called shrimps, and are used to make the traditional English dish of potted shrimps. Australia and some other Commonwealth nations follow this British usage to an even greater extent, using the word "prawn" almost exclusively. When Australian comedian Paul Hogan used the phrase, "I'll slip an extra shrimp on the barbie for you" in an American television advertisement, it was intended to make what he was saying easier for his American audience to understand, and was thus a deliberate distortion of what an Australian would typically say. The French term crevette is often encountered in restaurants.

Slipper lobsters are a family (Scyllaridae) of about 90 species of achelate crustaceans, in the Decapoda clade Reptantia, found in all warm oceans and seas. They are not true lobsters, but are more closely related to spiny lobsters and furry lobsters. Slipper lobsters are instantly recognisable by their enlarged antennae, which project forward from the head as wide plates. All the species of slipper lobsters are edible, and some, such as the Moreton Bay bug and the Balmain bug (Ibacus peronii) are of commercial importance.