For other uses, see Crab (disambiguation).

The term crab is sometimes applied to several different groups of short (nose to tail) Decapods The crayfish, a typical decapod Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacean Class: Malacostraca Order: Decapoda Suborders Either suborders: Natantia Reptantia or suborders: Dendrobranchiata Pleocyemata The decapods or Decapoda are a group of crustaceans within the class Malacostraca. They are usually considered to constitute an order, though some... decapods with thick exoskeletons, but only members of the Brachyura are true crabs; other taxa, such as Hermit crab A hermit crab from the Gulf of Thailand Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Decapoda Suborder: Pleocyemata Infraorder: Anomura Superfamily: Paguroidea Hermit crabs are decapod crustaceans of the infra-order Paguroidea, distinct from the true crabs in the infra-order Brachyura. Most hermit... hermit crabs, porcelain crabs, Spiny King Crab (Paralithodes rathbuni) King crab can refer to several species of arthropod: The horseshoe crab Two hermit crab genera in the in the superfamily Paguroidea: Lithodes, including the species: Scarlet king crab, Lithodes couesi (Benedict, 1894) † Golden king crab, Lithodes aequispinus (an Alaska king crab) ††... king crabs, and Horseshoe crab Pair of horseshoe crabs on the shore of Chesapeake Bay Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Merostomata Order: Xiphosura Family: Limulidae Genus: Limulus Species: polyphemus Binomial name Limulus polyphemus The horseshoe crab (Limulus polyphemus) also known as King Crab, is an arthropod that is more closely related... horseshoe crabs are, despite superficial similarities, not crabs at all. Hermit crab A hermit crab from the Gulf of Thailand Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Decapoda Suborder: Pleocyemata Infraorder: Anomura Superfamily: Paguroidea Hermit crabs are decapod crustaceans of the infra-order Paguroidea, distinct from the true crabs in the infra-order Brachyura. Most hermit... Hermit crabs, Spiny King Crab (Paralithodes rathbuni) King crab can refer to several species of arthropod: The horseshoe crab Two hermit crab genera in the in the superfamily Paguroidea: Lithodes, including the species: Scarlet king crab, Lithodes couesi (Benedict, 1894) † Golden king crab, Lithodes aequispinus (an Alaska king crab) ††... king crabs and porcelain crabs belong to the Anomala and can be distinguished from true crabs by counting the legs - in Anomala, the last pair of pereiopods (walking legs) is hidden inside the The term carapace refers to a dorsal section of an exoskeleton or shell, in a number of animal groups. Crustaceans In crustaceans, the carapace is a part of the exoskeleton that covers the cephalothorax. It is particularly well developed in lobsters and crabs. Tortoises Categories: Biology stubs ... carapace and so only four pairs are visible (counting the claws), whereas uninjured true crabs always have five visible pairs.

True crabs

True crabs are Crustaceans Hyalella azteca Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Classes Remipedia Cephalocarida Branchiopoda Ostracoda Maxillopoda Malacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum. They include various familiar animals, such as lobsters, crabs, shrimp and barnacles. They are variously... crustaceans in the Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. Modern classification has its roots in the system of Carolus Linnaeus, who grouped species according to shared physical characteristics. These groupings have been revised since Linnaeus to improve consistency with the Darwinian... suborder Brachyura, in the Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. Modern classification has its roots in the system of Carolus Linnaeus, who grouped species according to shared physical characteristics. These groupings have been revised since Linnaeus to improve consistency with the Darwinian... order Decapods The crayfish, a typical decapod Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacean Class: Malacostraca Order: Decapoda Suborders Either suborders: Natantia Reptantia or suborders: Dendrobranchiata Pleocyemata The decapods or Decapoda are a group of crustaceans within the class Malacostraca. They are usually considered to constitute an order, though some... Decapoda. They have five pairs of walking legs (the first of which is modified into a pair of claws or chelae) and typically a flattened shell. In all but a few crabs (for example, Raninoida), the The abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. The front of the abdomen is the abdominal cavity, which is separated from the thoracic cavity by the diaphragm. The lining of the abdomen is called the peritoneum, and the... abdomen is folded under the cephalothorax. The form of the abdomen usually reveals the sex of the crab - males have a narrow abdomen, while females have a much wider abdomen, under which they carry their An average Whooping Crane egg is 102 mm long, and weighs 208 grams A baby tortoise emerges from a reptile egg. In some animals, an egg is the zygote, resulting from fertilization of the ovum. It nourishes and protects the embryo. Oviparous animals are animals that lay eggs, with little... eggs. Crabs are a very diverse group, mostly found in salt water, but with some groups living in For the village on the Isle of Wight, see Freshwater, Isle of Wight. Fresh water (also freshwater or fresh-water) is water that contains only minimal quantities of dissolved salts, especially sodium chloride, thus distinguishing it from sea water or brackish water. All freshwater ultimately comes from precipitation of atmospheric... freshwater or on land. Although famed for their tendency to walk sideways, crabs are in fact able to walk in any direction.

Classification within the crabs is traditionally based on the position of the gonopores: whether they are found on the legs or on the Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body, that lies between the head and the abdomen. In humans, the thorax is the region of the body that extends from the neck to the diaphragm, not including the... thorax. In the two "primitive" sections (sometimes called collectively the "Podotremata"), the gonopores are found on the legs (as in all other decapods); in the Heterotremata, the male gonopores are on the legs, and the female gonopores are on the Sternum or breastbone is a long, flat bone located in the center of the thorax (chest). It connects to the rib bones via cartilage, forming the rib cage with them, and thus helps to protect the lungs and heart from physical trauma. The sternum is usually cut open (a sternotomy... sternum; in the Thoracotremata, the gonopores are on the sternum in both males and females.

See also

• Category:Crabs

Other animals

A number of animals with a similar shape are commonly called crabs, including the Crab Lice (singular, louse), Pthius pubis commonly called Crabs, are one of three kinds of human lice in the large group of lice families. (The others are Head lice and Body lice, which live in clothing.) They are wingless, about 1 to 3 mm long. They attach themselves to hair... crab louse (an Insects Hymenoptera Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Hexapoda Class: Insecta Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea... insect) and the Horseshoe crab Pair of horseshoe crabs on the shore of Chesapeake Bay Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Merostomata Order: Xiphosura Family: Limulidae Genus: Limulus Species: polyphemus Binomial name Limulus polyphemus The horseshoe crab (Limulus polyphemus) also known as King Crab, is an arthropod that is more closely related... horseshoe crab (in the class Merostomata Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Chelicerata Class: Merestomata Orders see text Merostomata is a class of marine arthropods which includes horseshoe crabs and eurypterids. It includes only four living species. Contents // 1 Classification 1.1 Order Eurypterida 1.2 Order Xiphosura 2 Reference Classification Class Merostomata Order... Merostomata). The crab louse is the origin of the slang term "crabs" for an infestation of Phthirus pubis Pubic lice (Phthirus pubis), also known as crabs , are one of the many varieties of lice (singular louse) specialized to live on different areas of different animals. As the name implies, pubic lice are specialized to live in the human pubic hair, but may also live in hair... pubic lice.