Callichirus major | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Malacostraca |
Order: | Decapoda |
Suborder: | Pleocyemata |
Family: | Callianassidae |
Genus: | Callichirus |
Species: | C. major |
Binomial name | |
Callichirus major Say, 1818 | |
Species | |
C. macrotelsonis , C. major s.s., C. aff. major sp. 1, C. aff. major sp. 2 Contents | |
Synonyms | |
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Callichirus major sensu lato is a monophyletic species complex of ghost shrimp in the infraorder Axiidea, found in flat sandy beaches across the Pan-American coastline.
Originally described as a single species, genetic studies eventually classified it as at least four almost morphologically indistinguishable species, one of which was given the binomial denomination Callichirus macrotelsonis (Peiró, 2012). The complex is distinguished by sexual dimorphism, distinctly separated coxae and bases in the maxilla and gonochorism, despite vestigial signs of ancestral hermaphroditism in C. macrotelsonis.
The widespread extraction of individuals for living fishing bait has endangered both its conservation and that of their respective ecosystems.
Callichirus major was first described as Callianassa major by Thomas Say in 1818, specifically in the Gulf of Mexico and East Florida. [1] Its genus was renamed Callichirus in 1866 by William Stimpson. [2] It used to be classified in the infraorder Thalassinidea (ghost shrimp) of decapod crustaceans until this infraorder was proven to be paraphyletic in 2009, after which the family Callianassidae, in which C. major is included, was definitely placed in the infraorder Axiidae (de Saint Laurent, 1979). [3] A supposed Brazilian species described as Anomalocaris macrotelsonis (Ortmann, 1893) was eventually discovered in 1974 to be the fourth larval stage of C. major. [4]
In 1995, the results of genetic testing published by Staton and Felder concluded that Caribbean Colombian populations described as C. major could not belong to the same species as those found in the United States Atlantic Ocean. Among those in the United States, although there were minor morphological differences between the populations of the East Coast (from North Carolina to Georgia) and those of the Gulf of Mexico (from Louisiana to Texas), the overall internal diversity of each population made them genetically indistinguishable. [5] Samples of Pacific Mexican ghost shrimps also later suggested a species not identical, but close to C. major s.s. [6]
Further testing by Peiró confirmed that populations of the East Coast and the Gulf of Mexico belonged to the same species, which was in turn different from the Colombian ones, but C. major was definitely described not as only two, but four distinct species with a monophyletic origin. Apart from C. major stricto sensu in the United States, the Colombian populations were found to belong to a different species than those of Pacific Mexico and Costa Rica. Those were described simply as C. aff. major sp. 2 and C. aff. major sp. 1, still pending binomial naming. The Brazilian populations, on the other hand, were successfully described as a fourth one, designed as C. macrotelsonis . [7] The relative genetical proximity between Caribbean and Pacific populations implies a separation posterior to the uplift of the Isthmus of Panama. [8] Rio confirmed Peiró's tests at a morphological level, suggesting that the absolute lack of information on vestigial signs of hermaphroditism in C. major s.s. might indicate that this feature could be exclusive of the Brazilian species, which she denominated C. brasiliensis sp. nov. [9]
Based on descriptions by Sakai and Türkay in 2012, Felder and Dworschak suggested that the formers' denomination C. santarosaensis might be ascribed to populations formerly designated as C. major in the northern Gulf of Mexico, although pending further genetic analysis and casting doubt on the validity of Sakai's and Türkay's description of a damaged juvenile specimen, prejudicing the validity of the taxon. [10] [11]
The great morphological similarities between all species of the C. major complex has proven to be a difficulty for the distinction of its closely related species. [12]
The C. major has a carapace with a rigid anterior margin, turning backwards to the linea thalassinica (an uncalcified membranous groove, in the complex's case distinctly parallel to the longitudinal axis of the body) and forwards to the rounded angles of the branchiostegal lung. The sternum is inconspicuous between the first and third pairs of pereopods. The complex has a flanked rostrum, with characteristically obtuse angles near the base of the eyestalks, which in turn almost reach the basal segment of the antennules' peduncles. The antennules have a third segments 1.5 to 2.5 times as longer as the first and second together. [13]
The maxilla has distinctly separated coxae and bases. The first pair of pereopods is very unequal in size, especially in adult males, presenting a uniquely bold instance sexual dimorphism in the genus. The second pair is well chelated, but the fourth and fifth have rather imperfect chelae. The first and second segments of the abdomen are membranous and soft, the latter being longer than the first, and almost twice as long as the third, fourth and sixth segments. The third, fourth and sixth segments have approximately the same length, although the fifth is slightly longer than its adjacent segments. [14]
Distinctly for its genus, C. major is gonochoristic. The vestigial signs of ancestral hermaphroditism (namely, the production of unused ovaries by males and additional gonopores in females) in C. macrotelsonis and the fully functional hermaphroditism in sister species such as C. seillacheri , however, implies that the genus Callichirus may have a unique case of crustacean basal, but not universal, hermaphroditism. [15]
C. major s.l. occurs in open, dissipative and flat sandy beaches, mostly in deep galleries in the intertidal zone, but also in shallow subtidal depths of 2–3 m. [1] It has a very large geographic distribution across Pan-American coastlines. In the Atlantic coastline, the distribution occurs from North Carolina to Santa Catarina, although with a large hiatus from Southern Texas to Pará, being therein only sporadically found in Colombia and Venezuela. [1] [16] In the Pacific coastline, the complex has been identified in both Baja California and Costa Rica. [8] [16]
C. major s.l. is widely employed as living fishing bait by many human coastal populations, including those in the United States and Brazil, due to its easy availability. [17] Ghost shrimp mass extraction, both specifically regarding C. major and generically, has been described as ecologically harmful not only for their own ecological stability, but also to different animals that are killed in the procedure. [18] The complex's IUCN status has been suggested as critically endangered, although it has not been officially reviewed by the IUCN. [19]
The Caridea, commonly known as caridean shrimp or true shrimp, from the Greek word καρίς, καρίδος, are an infraorder of shrimp within the order Decapoda. This infraorder contains all species of true shrimp. They are found widely around the world in both fresh and salt water. Many other animals with similar names – such as the mud shrimp of Axiidea and the boxer shrimp of Stenopodidea – are not true shrimp, but many have evolved features similar to true shrimp.
Stenopus hispidus is a shrimp-like decapod crustacean belonging to the infraorder Stenopodidea. Common names include coral banded shrimp and banded cleaner shrimp.
Thalassinidea is a former infraorder of decapod crustaceans that live in burrows in muddy bottoms of the world's oceans. In Australian English, the littoral thalassinidean Trypaea australiensis is referred to as the yabby, frequently used as bait for estuarine fishing; elsewhere, however, they are poorly known, and as such have few vernacular names, "mud lobster" and "ghost shrimp" counting among them. The burrows made by thalassinideans are frequently preserved, and the fossil record of thalassinideans reaches back to the late Jurassic.
Axiidea is an infraorder of decapod crustaceans. They are colloquially known as mud shrimp, ghost shrimp, or burrowing shrimp; however, these decapods are only distantly related to true shrimp. Axiidea and Gebiidea are divergent infraoders of the former infraorder Thalassinidea. These infraorders have converged ecologically and morphologically as burrowing forms. Based on molecular evidence as of 2009, it is now widely believed that these two infraorders represent two distinct lineages separate from one another. Since this is a recent change, much of the literature and research surrounding these infraorders still refers to the Axiidea and Gebiidea in combination as "thalassinidean" for the sake of clarity and reference. This division based on molecular evidence is consistent with the groupings proposed by Robert Gurney in 1938 based on larval developmental stages.
Callianassidae is a family of ghost shrimp crustaceans belonging to the infraorder Axiidea, within the order Decapoda.
Filhollianassa filholi is a ghost shrimp of the family Callianassidae, endemic to New Zealand, which grows up to 60 mm (2.4 in) long. It was known as Biffarius filholi until a 2019 taxonomic revision of the group.
Vulcanocalliax arutyunovi is a species of Thalassinidea found on a mud volcano in the Gulf of Cádiz between Spain and Morocco. It was discovered during the Census of Marine Life, and is so distinct from its closest relatives that it has been placed in a new subfamily, the Vulcanocallianacinae. The species is unusually large for a ghost shrimp, but despite that appears to brood only a single embryo. The species is named after the volcano on which it was discovered, Captain Arutyunov.
Polychelida is an infraorder of decapod crustaceans. Fossil representatives are known dating from as far back as the Upper Triassic. A total of 38 extant species, all in the family Polychelidae, and 55 fossil species have been described.
Clausidium is a genus of copepods that have been found in subtopical to temperate coastal areas along the Pacific, Atlantic and Gulf coasts of North America, the Pacific and Atlantic Coasts of South America, the Atlantic and Mediterranean coasts of Europe, the Atlantic coast of Africa, and the coast of India.
Lysmata is a genus of shrimp in the infraorder Caridea, the caridean shrimp. The genus belongs to the family Lysmatidae. Lysmata are popular ornamental shrimp in the marine aquarium trade for their bright color patterns, interesting behaviors, and ability to control certain aquarium pests such as sea anemones of the genus Aiptasia. They are known to command high prices on the pet market.
Neotrypaea californiensis, the Bay ghost shrimp, is a species of ghost shrimp that lives on the Pacific coast of North America. It is a pale animal which grows to a length of 11.5 cm (4.5 in). One claw is bigger than the other, especially in males, and the enlarged claw is thought to have a function in mating. N. californiensis is a deposit feeder that lives in extensive burrow systems, and is responsible for high rates of bioturbation. It adversely affects oyster farms, and its numbers are controlled in some places by the application of pesticides. It carries out an important role in the ecosystem, and is used by fishermen as bait.
Biffarius is a genus of ghost shrimp in the family Callianassidae, containing species formerly included in the genus Callianassa. Its members are small and generally live in the intertidal zone. In April 2020, a new species was described from the northeastern Brazilian coast. Biffarius was named in honour of Thomas A. Biffar, and includes the following species:
Lepidophthalmus turneranus, the Cameroon ghost shrimp, is a species of "ghost shrimp" or "mud lobster" that lives off the coast of West Africa. It occasionally erupts into dense swarms, one of which resulted in the naming of the country Cameroon.
Calliapagurops charcoti is a species of mud shrimp from Macaronesia. It is the only mud shrimp known from Madeira, and is the only species of mud shrimp thought to be a filter feeder.
Macromaxillocaris bahamaensis is a species of stenopodidean shrimp, the only species in the family Macromaxillocarididae. It is a troglobite, known only from an anchialine pool in a cave in the Bahamas. It differs from other stenopodideans by the enlargement of its third maxilliped.
Calliapagurops is a genus of mud shrimp containing two species:
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.
Kraussillichirus kraussi, commonly named the common sandprawn or pink prawn, is a species of ghost shrimp, an African crustacean in the family Callichiridae.
Callichirus is a genus of crustaceans belonging to the family Callianassidae. It was circumscribed by William Stimpson in 1866.
Clausidium dissimile is a species of copepod that has been found along the Atlantic and Gulf Coasts from Massachusetts to Florida. They are found on the bodies of mud shrimp of the family Callianassidae, or from water collected from mud shrimp burrows.