Synalpheus | |
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Synalpheus fritzmuelleri | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Malacostraca |
Order: | Decapoda |
Suborder: | Pleocyemata |
Infraorder: | Caridea |
Family: | Alpheidae |
Genus: | Synalpheus Bate, 1888 |
Type species | |
Synalpheus falcatus Bate, 1888 [1] | |
Species | |
See species list | |
Synonyms | |
List
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Synalpheus is a genus of snapping shrimp of the family Alpheidae, presently containing more than 160 species; new ones are described on a regular basis, and the exact number even of described species is disputed.
Although the genus Zuzalpheus was proposed for S. gambarelloides, S. brooksi, and their closest relatives, this has not been adopted and is not considered a monophyletic clade within the genus Synalpheus. [2] [3] [4]
Over 160 species are recognised in the genus Synalpheus. For a complete listing, see List of Synalpheus species.
In the narrower sense, Synalpheus occur in the eastern Pacific where they are most plentiful and probably originated, and to a lesser extent in the Atlantic and the Indian Ocean; the species placed in Zuzalpheus occur mainly in the western Atlantic where their lineage probably originated, and to a lesser extent in the eastern Atlantic and Indian Ocean, and the eastern Pacific. It may thus be that the closure of the Isthmus of Panama in the Piacenzian (about 3 million years ago) was a key factor in separating the two lineages, as species referred to Synalpheus sensu stricto are most plentiful in the western Pacific. [4]
The snapping behaviour of Synalpheus is rather well studied. In Synalpheus parneomeris, peak to peak source levels of 185–190 dB re 1 μPa at 1 m were measured, depending on the size of the claw. [5]
The only known eusocial aquatic species occur within the genus Synalpheus. The species known to be eusocial are S. brooksi, S. chacei, S. elizabethae, S. filidigitus, S. rathbunae, S. regalis, [2] S. microneptunus, [6] and S. duffyi as well as potentially S. riosi. [7] Eusociality has evolved at least three times within Synalpheus. [3] [8] It appears that there were multiple rapid radiations between 3 and 9 mya from which the ancestors of these eusocial species appeared. [8] Eusociality is thought to have arisen due to competition for space, because among the species that host Synalpheus, empty sponges are rarely found. [9] It also appears that kin selection was necessary for this evolution to occur because the only species in which eusociality has appeared are non-dispersing shrimp that hatch directly into crawling individuals. [10] Until recently, eusocial species of Synalpheus have appeared in far greater abundance than, and appear to outcompete, less social species for space in sponges. [9] [11]
Alpheidae is a family of caridean snapping shrimp, characterized by having asymmetrical claws, the larger of which is typically capable of producing a loud snapping sound. Other common names for animals in the group are pistol shrimp or alpheid shrimp.
Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies.
Metabetaeus is a genus of shrimp in the family Alpheidae, comprising four species:
Troglocaris is a genus of freshwater shrimp in the family Atyidae. These stygobitic, whitish and eyeless shrimp are found in Southern Europe. Although locally very common, the small ranges of the individual species make them highly vulnerable to habitat loss, for example by water extraction. Their underground habitat is often extremely stable; for example, the Vipavska jama cave in Slovenia is home to a population of T. anophthalmus, and its water only varies from 10 °C (50 °F) in the winter to 11 °C (52 °F) in the summer. In some Dinaric caves, notably Vjetrenica, as many as three species may occur together.
Eusociality, the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care, overlapping generations within a colony of adults, and a division of labor into reproductive and non-reproductive groups. The division of labor creates specialized behavioral groups within an animal society which are sometimes referred to as 'castes'. Eusociality is distinguished from all other social systems because individuals of at least one caste usually lose the ability to perform at least one behavior characteristic of individuals in another caste. Eusocial colonies can be viewed as superorganisms.
The Pylochelidae are a family of hermit crabs. Its members are commonly called the 'symmetrical hermit crabs'. They live in all the world's oceans, except the Arctic and the Antarctic, at depths of 2,000 m (6,600 ft). Due to their cryptic nature and relative scarcity, only around 60 specimens had been collected before 1987, when a monograph was published detailing a further 400.
Eusociality evolved repeatedly in different orders of animals, notably termites and the Hymenoptera. This 'true sociality' in animals, in which sterile individuals work to further the reproductive success of others, is found in termites, ambrosia beetles, gall-dwelling aphids, thrips, marine sponge-dwelling shrimp, naked mole-rats, and many genera in the insect order Hymenoptera. The fact that eusociality has evolved so often in the Hymenoptera, but remains rare throughout the rest of the animal kingdom, has made its evolution a topic of debate among evolutionary biologists. Eusocial organisms at first appear to behave in stark contrast with simple interpretations of Darwinian evolution: passing on one's genes to the next generation, or fitness, is a central idea in evolutionary biology.
Synalpheus carpenteri is a species of sponge-dwelling snapping shrimp described in 2006 from specimens collected from the Belizean Barrier Reef of the Exuma Islands, Bahamas, and the Atlantic coast of Panama. Its most identifying characteristic is the faint to bright orange overall color of the body. The species is named in honor of Michael Carpenter, Caribbean Coral Reef Ecosystem program, National Museum of Natural History, Smithsonian Institution, Washington, D.C.
Synalpheus regalis is a species of snapping shrimp that commonly live in sponges in the coral reefs along the tropical West Atlantic. They form a prominent component of the diverse marine cryptofauna of the region. For the span of their entire lives, they live in the internal canals of the host sponge, using it as a food resource and shelter. It has been shown that colonies contain over 300 individuals, but only one reproductive female. Also, larger colony members, most of which apparently never breed, defend the colony against heterospecific intruders. This evidence points towards the first known case of eusociality in a marine animal.
Synalpheus microneptunus is a species of small snapping shrimp native to the waters off the island of Barbados. It is one of at least seven known species of eusocial shrimp. They are cryptofauna, living exclusively within the network of tunnels in the sponges Neopetrosia proxima and Neopetrosia subtriangularis. They form small colonies of six to fifteen individuals, usually with only a single breeding female.
Neopetrosia proxima is a species of marine petrosiid sponge native to the tropical and subtropical waters of the western Atlantic Ocean.
Neopetrosia subtriangularis is a species of marine petrosiid sponges native to the waters off Florida and the Caribbean Sea. They superficially resemble staghorn corals.
Alpheus tricolor is a crustacean belonging to the family of snapping shrimp. It was first isolated in Indonesia and Sri Lanka. It counts with a setose carapace, an acute rostrum, shallow adrostral furrows and a basicerite with a strong ventrolateral tooth. The lamella of its scaphocerite is not reduced, with an anterior margin that is concave. Its third maxilliped counts with an epipodial plate bearing thick setae, while its first chelipeds are found with their merus bearing a strong disto-mesial tooth; its third pereiopod has an armed ischium, with a simple and conical dactylus. Its telson is broad, distally tapering, with 2 pairs of dorsal spines. The species is named after its characteristic colour pattern, including white, red and orange.
Alpheus fasqueli is a crustacean belonging to the family of snapping shrimp. It was first isolated in Sri Lanka. It counts with a setose carapace, an acute and carinate rostrum, and unarmed orbital hoods. Its basicerite has a strong ventrolateral tooth. The lamella of its scaphocerite is not reduced. Its third maxilliped counts with an epipodial plate bearing thick setae, while its first chelipeds are found with their merus bearing a strong disto-mesial tooth; its third pereiopod has an armed ischium, with a simple and conical dactylus. Its telson is broad, distally tapering, with 2 pairs of dorsal spines. The species is named after Frédéric Fasquel, a photographer who contributed rare shrimp specimens for the Muséum national d'histoire naturelle.
Synalpheus pinkfloydi, the Pink Floyd pistol shrimp, is a species of snapping shrimp in the genus Synalpheus. Described in 2017, it was named after the rock band Pink Floyd, in part because it has a distinctive "bright pink-red claw". The sound it makes by snapping the claw shut reaches 210 decibels, and can kill nearby small fish.
Alpheus digitalis is a species of pistol shrimp in the family Alpheidae. The species was first discovered after a taxonomic study of a snapping shrimp from the genus Alpheus from Japan and the Gulf of Thailand, of which, it was found that two species was confounded under A.digitalis, which was originally described based on a single specimen possessing abnormal chelipeds.
Athanas sydneyensis is a species of small alpheid shrimp.
Metabetaeus lohena, also known as the alpha snapping shrimp or anchialine snapping shrimp, is a species of alpheid shrimp native to Hawaii and Easter Island.
Alpheus malleator, the hammerclaw snapping shrimp or bumpy-clawed snapping shrimp, is a species of marine snapping shrimp. It is considered the most distinctive species in the genus Alpheus due to intricate morphological features.