Crustaceans are animals that do not have a vertebra and backbone and have a hard shell outside. The body of crustaceans is divided into three parts. These are head, thorax, and abdomen. Body consists of segments and jointed legs. Commercially used crusta
The structure, growth, differentiation and function of crustacean chelipeds are reviewed. In many decapod crustaceans growth of chelae is isometric with allometry level reaching unity till the puberty moult. Afterwards the same trend continues in females, while in males there is a marked spurt in t...
Cambrian to present; body short; bivalved carapace encloses trunk and limbs; living forms have up to 7 pairs of appendages; most fossils known only from shells (carapaces); marine, freshwater, and some terrestrial; more than 2,000 living species worldwide. †Order Bradoriida Cambrian to Or...
In the decapods there are three sets of paired maxillipeds. In the copepods the maxillipeds are followed by four pairs of swimming legs; a fifth pair is sometimes highly modified for reproductive purposes and is sometimes reduced to a mere vestige. Behind the decapod maxillipeds there are five...
The true lobsters (Homaridae) have claws (chelae) on the first three pairs of legs, with very large claws on the first pair. They have a distinct rostrum, or snout, on the carapace, which covers the head and thorax, or midsection. The American lobster (Homarus americanus) and the Norw...
Burrowing barnacles (order Acrothoracica, about 30 species) are small, unisexual forms that lack shells and have fewer than six pairs of cirri. They burrow into hard limy material, such as clam shells and coral. Trypetesa is found only inside snail shells occupied by hermit crabs. Parasitic...
The presence of five pairs of thoracic legs (pereiopods) is the basis for the name decapod (from the Greek meaning “10 legs”). Members of the order exhibit great diversity in size and structure. The macrurous (shrimplike) species, which can be as small as 1 cm (0.5 inch), have ...
Order ThoracicaSilurian to present; the true barnacles; most are nonparasitic; larvae are nauplii and cyprids; adult body typically contained within calcareous shell plates; about 800 species.Subclass TantulocaridaHolocene; eggs give rise to a tantulus larva with head shield and 6 pairs of thoracic...
The presence of five pairs of thoracic legs (pereiopods) is the basis for the name decapod (from the Greek meaning “10 legs”). Members of the order exhibit greatdiversityin size and structure. The macrurous (shrimplike) species, which can be as small as 1 cm (0.5 inch), have elon...