| Grapsus grapsus | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Family: | Grapsidae |
| Genus: | Grapsus |
| Species: | G. grapsus |
| Binomial name | |
| Grapsus grapsus | |
| Synonyms [1] | |
| |
Grapsus grapsus is one of the most common crabs along the western coast of the Americas. It is known as the red rock crab, or, along with other crabs such as Percnon gibbesi , as the Sally Lightfoot crab.
Grapsus grapsus is found along the Pacific coast of Mexico, Central America, and South America (as far south as northern Peru), and on nearby islands, including the Galápagos Islands. It is also found along the Atlantic coast of South America, but is replaced in the eastern Atlantic Ocean (Ascension Island and West Africa) by its congener Grapsus adscensionis . [2]
Grapsus grapsus is a typically shaped crab, with five pairs of legs, the front two bearing small, blocky, symmetrical chelae (claws). The other legs are broad and flat, with only the tips touching the substrate. The crab's round, flat carapace is slightly longer than 8 centimetres (3.1 in). Young G. grapsus are black or dark brown in colour and are camouflaged well on the black lava coasts of volcanic islands. Adults are quite variable in colour; some are muted brownish-red, some mottled or spotted brown, pink, or yellow.
Grapsus grapsus was first described by Carl Linnaeus in the 1758 10th edition of Systema Naturae as "Cancer grapsus". [1]
The species Grapsus grapsus and G. adscensionis were not separated until 1990. The latter is found in the eastern Atlantic, while the former is not. [3] While the validity of the separation into two species has been questioned, there are constant morphological differences in the colouration of the pereiopods and the form of the first zoea larva, and no evidence for any genetic connection between the two populations, and they are generally treated as separate species.[ citation needed ]
This crab lives among the rocks at the often turbulent, windy shore, just above the limit of the sea spray. It feeds on algae primarily, sometimes sampling other plant matter, sponges, mollusks (such as clams), crustaceans (including other crabs), fishes, young sea turtles, bird eggs and droppings, bat guano and dead animals (mainly seals and birds). [4] As larvae, they feed on phytoplankton. [5] They have been known to resort to cannibalism when populations densities are high or food is scarce. [4] It is an agile crab, capable of leaping, [6] and consequently hard to catch. Not considered very edible by humans, it is used as bait by fishermen. It is preyed upon by the chain moray eel, Echidna catenata, as well as by octopuses. [7] [8]
G. grapsus has been observed in an apparent cleaning symbiosis taking ticks from marine iguanas on the Galápagos Islands. [9]
Grapsus grapsus was collected by Charles Darwin during his voyages on HMS Beagle, [10] and also by the first comprehensive study of the fauna of the Gulf of California, carried out by Ed Ricketts, together with John Steinbeck and others. Steinbeck records: [11]
These little crabs, with brilliant cloisonné carapaces, walk on their tiptoes, They have remarkable eyes and an extremely fast reaction time. In spite of the fact that they swarm on the rocks at the Cape [San Lucas], and to a less degree inside the Gulf [of California], they are exceedingly hard to catch. They seem to be able to run in any of four directions; but more than this, perhaps because of their rapid reaction time, they appear to read the mind of their hunter.
Stenorhynchus seticornis, the yellowline arrow crab or simply arrow crab, is a species of marine crab.
Gecarcinus quadratus, known as the red land crab, whitespot crab, Halloween crab, moon crab, Halloween moon crab, mouthless crab, or harlequin land crab, is a colourful land crab from the family Gecarcinidae.
Tuerkayana hirtipes is a species of terrestrial crab.
Leptograpsus variegatus, known as the purple rock crab, is a marine large-eyed crab of the family Grapsidae, found in southern subtropical Indo-Pacific Oceans. It grows to around 50 millimetres (2.0 in) shell width. It is the only species in the genus Leptograpsus.
Charybdis is a genus of swimming crabs in the family Portunidae. It is named after the monster Charybdis of Greek mythology.
Latreilliidae is a small family of crabs. They are relatively small, long-legged crabs found on soft bottoms at depths of up 700 metres (2,300 ft) in mostly tropical and subtemperate waters around the world. Their carapace is very small and doesn’t cover the bases of their legs, which protrude from the cephalothorax in a spider-like manner. The family and its type genus are named after Pierre André Latreille. The oldest known fossils from the Latreillidae have been dated to the middle of the Cretaceous period. It comprises seven extant species.
Goneplax rhomboides is a species of crab. It is known by the common name angular crab because of its angular carapace. Although it is also called the square crab, its shell is in fact more trapezoidal than square. This species is also known as the mud-runner because they are able to run away quickly when threatened.
Percnon gibbesi is a species of crab. It is one of at least two species commonly called Sally Lightfoot, and is also referred to as the nimble spray crab or urchin crab. It has been described as "the most invasive decapod species to enter the Mediterranean".
Xantho poressa, the jaguar round crab, is a species of crab from the eastern Atlantic Ocean. It is one of four species in the genus Xantho.
Dromia dormia, the sleepy sponge crab or common sponge crab, is the largest species of sponge crab. It grows to a carapace width of 20 cm (8 in) and lives in shallow waters across the Indo-Pacific region.
Pisidia longicornis, the long-clawed porcelain crab, is a species of porcelain crab that lives in the north-eastern Atlantic Ocean. It varies from reddish to white, and grows to a carapace width of 1 cm (0.4 in). It was first named by Carl Linnaeus in 1767, although the etymology remains unclear.
Inachus phalangium, Leach's spider crab, is a species of crabs from the north-eastern Atlantic Ocean and Mediterranean Sea. It is up to 20.5 mm (0.81 in) wide, and is very similar to other species in the genus Inachus.
Calcinus tubularis is a species of hermit crab. It is found in the Mediterranean Sea and around islands in the Atlantic Ocean, where it lives below the intertidal zone. Its carapace, eyestalks and claws are marked with numerous red spots. C. tubularis and its sister species, C. verrilli, are the only hermit crabs known to show sexual dimorphism in shell choice, with males using normal marine gastropod shells, while females use shells of gastropods in the family Vermetidae, which are attached to rocks or other hard substrates.
Zebrida adamsii is a distinctively striped species of crab that lives in association with a sea urchin in the Indo-Pacific region. It is cryptically coloured with vertical stripes and has special adaptations to its legs to enable it to cling to its host's spines.
Libinia dubia, the longnose spider crab, is a species of crab in the family Epialtidae. It is found in shallow waters on the eastern coast of North America.
Planes minutus is a species of pelagic crab that lives in the North Atlantic Ocean. It is typically less than 10 mm (0.4 in) long across the back, and is variable in colouration, to match its background. It may have been the crab seen by Christopher Columbus on Sargassum weed in the Sargasso Sea in 1492.
Geryon trispinosus is a species of crab that lives in deep water in the north-eastern Atlantic Ocean.
Brachynotus sexdentatus is a species of crab in the family Varunidae. It is native to the Mediterranean Sea and Black Sea, and became established for a time in Swansea Docks. It grows to a maximum carapace width of 18 mm (0.71 in), and lives in shallow water on muddy bottoms.
Geograpsus lividus is a species of crab in the family Grapsidae. Little research has been conducted on this species. It was originally classified as belonging to the genus Grapsus; however, this name is no longer used.
Leptuca uruguayensis, commonly known as the Uruguayan fiddler crab or the southwestern Atlantic fiddler crab, is a species of fiddler crab native to temperate and subtropical areas of the southeastern coast of South America.
Media related to Grapsus grapsus at Wikimedia Commons