| Albunea carabus | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Anomura |
| Family: | Albuneidae |
| Genus: | Albunea |
| Species: | A. carabus |
| Binomial name | |
| Albunea carabus | |
| Synonyms [1] | |
| |
Albunea carabus is a rare species of "sand crab" or "mole crab" in the family Albuneidae. It lives in shallow, turbulent waters in sandy areas of the tropical eastern Atlantic Ocean and the Mediterranean Sea.
Albunea carabus is typically up to 2 centimetres (0.8 in) long. In common with other species of Albunea, [2] it has a quadrangular carapace with a concave rear edge, and flattened legs, which it uses for digging in sand. [3] The first pair of pereiopods are subchelate (forming a claw with one movable finger pressing onto a solid edge, rather than a fixed finger), and all five pairs are flattened into shovels and are effective at digging. [4] The pleon (abdomen) is shorter than the carapace, and bears four pairs of pleopods in females, but none in males. The pleon ends in a telson flanked by a pair of uropods, which are similar in form to the pereiopods, and aid in digging. [4]
The larvae of Albunea carabus are likely to pass through five planktonic zoea instars before reaching the juvenile stage, as also seen in Albunea symmysta . Over the first three of these instars, the larvae increase from around 1.56 mm to around 2.72 mm in total length. [5] By the third zoea instar, the pereiopods begin to show as small buds, and uropods are present alongside the broad telson. [5]
Albunea carabus is found on parts the African coast of the Atlantic Ocean and in the Mediterranean Sea, where it is the only mole crab. [6] It is widespread in the western Mediterranean basin (Ligurian Sea and Tyrrhenian Sea), but is only known from very few records east of the Straits of Messina. These have included a site off the estuary of the Nahr Rubin river in Israel, [6] and several collections from the Gulf of İskenderun. [7] Albunea carabus has also been recorded from Ghana, Togo and Benin, [8] but records from Saint Helena, the Azores and Madeira could refer to the related species A. paretii . [9]
Albunea carabus typically lives slightly offshore, at depths of 3–40 m (10–131 ft), [6] in sandy environments where the water is very turbid. [10] It seems to prefer areas with strong hydrodynamics, including estuaries. [9]
Albunea carabus was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae , as "Cancer carabus". He had received the material from Erik Skjöldebrand ("E. Brander"), the Swedish consul in Algiers. [6] Friedrich Weber erected the new genus Albunea in 1795 for this species and Albunea symmysta . [1] Within the genus Albunea, Albunea carabus is placed in the informal "A. carabus group" of species, alongside A. bulla and A. danai . [8] The group also includes two fossil species – A. asymmetrica and A. turritellacola . [11]
Antoine Risso described "Hippa caerulea" as a new species in 1816; although this was synonymised with A. carabus by Lipke Holthuis in 1977 (with reservations), it is now thought to be an isopod of the genus Gnathia , perhaps Gnathia phallonajopsis . [2]
Dendrobranchiata is a suborder of decapods, commonly known as prawns. There are 540 extant species in seven families, and a fossil record extending back to the Devonian. They differ from related animals, such as Caridea and Stenopodidea, by the branching form of the gills and by the fact that they do not brood their eggs, but release them directly into the water. They may reach a length of over 330 millimetres (13 in) and a mass of 450 grams (1.0 lb), and are widely fished and farmed for human consumption.
The Decapoda or decapods are an order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfish, shrimp, and prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 extant species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp and Anomura including hermit crabs, porcelain crabs, squat lobsters making up the bulk of the remainder. The earliest fossils of the group date to the Devonian.
Emerita is a small genus of decapod crustaceans, known as mole crabs, sand fiddlers, or sand crabs. These small animals burrow in the sand in the swash zone and use their antennae for filter feeding.
Squat lobsters are dorsoventrally flattened crustaceans with long tails held curled beneath the cephalothorax. They are found in the two superfamilies Galatheoidea and Chirostyloidea, which form part of the decapod infraorder Anomura, alongside groups including the hermit crabs and mole crabs. They are distributed worldwide in the oceans, and occur from near the surface to deep sea hydrothermal vents, with one species occupying caves above sea level. More than 900 species have been described, in around 60 genera. Some species form dense aggregations, either on the sea floor or in the water column, and a small number are commercially fished.
Carcinisation is a form of convergent evolution in which non-crab crustaceans evolve a crab-like body plan. The term was introduced into evolutionary biology by L. A. Borradaile, who described it as "the many attempts of Nature to evolve a crab".
Raninidae is a family of unusual crabs, sometimes known as "frog crabs", on account of their frog-like appearance. They are taken by most scientists to be quite primitive among the true crabs. They closely resemble the (unrelated) mole crabs, due to parallel evolution or convergent evolution. In both groups, the claws are modified into tools for digging, and the body is a rounded shape that is easy to bury in sand. Unlike most other true crabs, the abdomens of raninids are not curled under the cephalothorax.
The decapod is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various groups these may be reduced or missing. They are, from head to tail:
Hippoidea is a superfamily of decapod crustaceans known as mole crabs or sand crabs.
Albuneidae is a little-known family of specialized burrowing sand crabs. There are 50 extant species as well as nine fossil species that have been described. Fossil specimens have been described from the Cretaceous, Miocene and Oligocene.
Albunea is a genus of mole crab within the Albuneidae. Little is known about this group's biology. A. groeningi is named after Matt Groening, creator of The Simpsons.
Pilumnus hirtellus, the bristly crab or hairy crab, is a species of European crab. It is less than 1 inch (25 mm) long and covered in hair. It lives in shallow water and feeds on carrion.
Polycheles typhlops is a species of blind, deep water decapod crustacean with a cosmopolitan distribution. It is "one of the dominant and most characteristic crustaceans in deep-sea communities of the Mediterranean Sea".
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.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
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.
Hippidae is a family of decapod crustaceans, currently known by the English name as either mole crab or sand crab, and by an earlier English name as sand bug. They are closely related to the family Albuneidae, with which they are usually joined in the superfamily Hippoidea. The family Hippidae comprises the three genera Emerita, Hippa and Mastigochirus. They burrow into sand, and are found throughout the world, except the Arctic and Antarctic.
Ogyrides, also known as long eyed shrimps, is a genus of decapod crustaceans consisting of 13 species. It is the only genus in the monotypic family Ogyrididae.
Automate branchialis is a species of pistol shrimp from the family Alpheidae which was thought to be a Lessepsian migrant, i.e. a species which had colonised the Mediterranean from the Red Sea via the Suez Canal. This was because before its description in 1958 all the species of the genus Automate were found in the Indo-Pacific region. A. branchialis has not been recorded in the Indo-Pacific region and has been found to be widespread in the Mediterranean so it is now considered to be a Mediterranean endemic.
Notopus dorsipes is a species of frog crab from the family Raninidae which has an Indo-Pacific distribution and which has recently spread into the eastern Mediterranean. It is the only extant species in the genus Notopus.
Pagurus forbesii is a species of hermit crab in the family Paguridae. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea.