Crab Image - Free Image Download
Printing and Framing Crab Prints (Artwork) for Your Home or Office
This page is designed to give you ideas on types of prints that might work and some general information around your chosen animal prints theme. Order prints and have them carefully rolled and safely secured in a cardboard cylinder and delivered to your door.
Female crab: hen
Male crab: cock, jimmy
A group of crabs is called: consortium, cast
Crab classification: cancrine
Crab class: Invertebrate
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting ail (Greek: /brachy = short, /ura = tail), or where the reduced abdomen is entirely hidden under the thorax. They are generally covered with a thick exoskeleton, and armed with a single pair of chelae (claws). 6,793 species are known. Crabs are found in all of the world's oceans. Additionally, there are also many freshwater and terrestrial crabs, particularly in tropical regions. Crabs vary in size from the pea crab, only a few millimetres wide, to the Japanese spider crab, with a leg span of up to 4 m.
The infraorder Brachyura contains about 93 families, as many as the remainder of the Decapoda. The evolution of crabs is characterised by an increasing robustness of the body, and a reduction in the abdomen. Although many other groups have also undergone similar processes of carcinisation, it is most advanced in crabs. The telson is no longer functional in crabs, and the uropods are absent, having probably evolved into small devices for holding the reduced abdomen tight against the sternum.
In most decapodes, the gonopores (sexual openings) are found on the legs. However, since crabs use the first two pairs of pleopods (abdominal appendages) for sperm transfer, this arrangement has changed. As the male abdomen evolved into a narrower shape, the gonopores have moved towards the midline, away from the legs, and onto the sternum. A similar change occurred, independently, with the female gonopores. The movement of the female gonopore to the sternum defines the clade Eubrachyura, and the later change in the position of the male gonopore defines the Thoracotremata. It is still a subject of debate whether those crabs where the female, but not male, gonopores are situated on the sternum form a monophyletic group.
The earliest unambiguous crab fossils date from the Jurassic, although the Carboniferous Imocaris, known only from its carapace is thought to be a primitive crab. The radiation of crabs in the Cretaceous and afterwards may be linked either to the break-up of Gondwana or to the concurrent radiation of bony fish, the main predators of crabs.
About 850 species of crab are freshwater or (semi-)terrestrial species; they are found throughout the world's tropical and semi-tropical regions. They were previously thought to be a closely related group, but are now believed to represent at least two distinct lineages, one in the Old World and one in the New World.
Crabs are decapodsten-legged omnivoresbut the front pair of legs are specialised with enlarged claws, so they are often described as eight-legged. Some species feed primarily on algae, while others take any type of food, including mollusks, worms, other crustaceans, fungi, bacteria, and detritus, depending on availability and on the species of crab. For many species, a mixed diet of plant and animal matter results in the fastest growth and greatest fitness.
Crabs make up 20% of all marine crustaceans caught and farmed worldwide, with over 1 million tonnes being consumed annually. Of that total, one species accounts for one fifth: Portunus trituberculatus. Other important taxa include Portunus pelagicus, several species in the genus Chionoecetes, the blue crab (Callinectes sapidus), Charybdis spp., Cancer pagurus, the Dungeness crab (Cancer magister) and Scylla serrata, each of which provides more than 20,000 tonnes annually .
What do you call a female crab?
What do you call a male crab?
What do you call a group of crabs?
Question: What is the scientific classification of a crab?
Question: What class is a crab in?