Cardisoma armatum
Encyclopedia
Cardisoma armatum is a species
of terrestrial crab
.
as adults and when being shipped to pet stores, they are often packed in soap dish
es to prevent them from killing each other. The names moon crab and soapdish crab are sometimes applied to other similar crab species, leading to frequent confusion with other colourful crabs such as the three remaining species of Cardisoma
, Gecarcinus ruricola
and G. quadratus (all except C. carnifex
from the Americas
).
, but it also occurs inland along some deltas (e.g. the Volta river
delta), and on islands such as Cape Verde.
, red–coloured legs, and whitish claws. This coloration usually fades as the animal grows older. They can reach a carapace size of 20 cm across, although captive individuals rarely reach this size.
, vegetation and carrion
. They are known to be cannibalistic
, and will consume smaller crabs, small reptile
s and amphibian
s, molluscs, fish
, and insect
s if they can catch them. While juvenile and adult crabs spend most of their time on dry land, the females must return to the ocean
to release their eggs. The eggs hatch into microscopic larvae, and later on develop into young crabs. If the young do not make landfall by the time they are fully developed they will drown.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of terrestrial crab
Land crab
Gecarcinidae is a family of true crabs that are adapted for terrestrial existence, commonly known as land crabs. Similar to all other crabs, land crabs possess a series of gills. In addition, the part of the carapace covering the gills is inflated and equipped with blood vessels. These organs...
.
Names
It is sometimes referred to as the (African) rainbow crab, (Nigerian) moon crab or patriot crab. Adults are sometimes labelled as soapdish crabs in the pet industry. This name derives from their aggressive natureAggression
In psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
as adults and when being shipped to pet stores, they are often packed in soap dish
Soap dish
A soap dish holds a bar of soap when not in use for hand washing or other cleaning, near a washing area such as a bathtub or washbasin. Soap dishes are made from waterproof materials such as plastic, ceramic and metal. Soap dishes may be mounted on the wall. For liquid soap or foam soap a soap...
es to prevent them from killing each other. The names moon crab and soapdish crab are sometimes applied to other similar crab species, leading to frequent confusion with other colourful crabs such as the three remaining species of Cardisoma
Cardisoma
Cardisoma is a genus of large land crabs. Three species formerly placed in this genus are now placed in Discoplax. The four species that remain in Cardisoma are found in warm coastal regions where they live in burrows...
, Gecarcinus ruricola
Gecarcinus ruricola
Gecarcinus ruricola is a species of terrestrial crab. It is the most terrestrial of the Caribbean land crabs, and is found from western Cuba across the Antilles as far east as Barbados. Common names for G...
and G. quadratus (all except C. carnifex
Cardisoma carnifex
Cardisoma carnifex is a species of terrestrial crab found in coastal regions from the east coast of Africa and the Red Sea across the Indo-Pacific to the Line Islands and the Tuamotu Archipelago. The range includes parts of northern Australia and the Cocos Islands....
from the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
).
Distribution
Cardisoma armatum originates from coastal regions of western AfricaAfrica
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, but it also occurs inland along some deltas (e.g. the Volta river
Volta River
The Volta is a river in western Africa that drains into the Gulf of Guinea. It has three main tributaries—the Black Volta, White Volta and Red Volta...
delta), and on islands such as Cape Verde.
Description
When young, these crabs typically have a blueish/violet carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
, red–coloured legs, and whitish claws. This coloration usually fades as the animal grows older. They can reach a carapace size of 20 cm across, although captive individuals rarely reach this size.
Ecology and life cycle
Their diet consists mainly of fruitFruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
, vegetation and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. They are known to be cannibalistic
Cannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
, and will consume smaller crabs, small reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s and amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, molluscs, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, and insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s if they can catch them. While juvenile and adult crabs spend most of their time on dry land, the females must return to the ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
to release their eggs. The eggs hatch into microscopic larvae, and later on develop into young crabs. If the young do not make landfall by the time they are fully developed they will drown.