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Dyspanopeus texanus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Crustacea |
Class: | Malacostraca |
Order: | Decapoda |
Suborder: | Pleocyemata |
Infraorder: | Brachyura |
Family: | Panopeidae |
Genus: | Dyspanopeus |
Species: | D. texanus |
Binomial name | |
Dyspanopeus texanus | |
Dyspanopeus texanus (formerly Panopeus texanus or Neopanope texana) is a species of crab known as the Texas mud crab. [2]
Dyspanopeus texanus are an organism that is found in the phylum Arthropoda, subphylum Crustacea, order of Decapoda, and finally in the newly erected superfamily: Xanthiadae. This new family was adopted before the 2000s by crustacean workers and has continued to gain acceptance over the last few decades. However, some other crustacean scientists have pointed out the inconsistent criteria upon which generic distinctions of xanthoid crabs are based. The differences between carapaces (shell) and cheliped (distinct, large claw appendage) morphology remain unclear. It is because of this, and the lack of information about the larval and postlarval stages of certain xanthoids that the families distinguishing different xanthoids have shifted so much over time. [3]
The Dyspanopeus texanus have a generally similar body to many other crustaceans. Its main carapace is a hexagonal shape with rivets on the sides closest to its eyes. D. texanus has four appendages on each side of its body, which are used for walking and swimming. There is a fifth appendage on each side of the crab closest to its eyes, which are called the chelipeds. These appendages have a relatively medium to small sized claw at the ends of them, which are used to attack prey. In many other species of crabs, one of these main claws are usually extremely large and are used to fight other males in order to gain the attention of females for mating. [4]
The Dyspanopeus texanus are also one of the most abundant and dominant crab species in the coastal lagoons of southwestern Gulf of Mexico, including Términos, Tamiahua, and Madre. The Texas Mud Carbs are also known as euryhaline species, which means that they can adapt to wide ranges of salinity, which is why they have been historically found living on macroalgae, seagrasses, and submerged aquatic vegetation. [5] In a study using different Carbon isotopes to determine the trophic levels of different xanthoid carbs, it found that D. texanus occupy the higher trophic levels in these ecosystems, meaning their diets are likely to consist of mostly primary producers like zooplankton and red algae. [6]
Knowledge of the reproduction of xanthoid crabs is quite sparse. The only information that could be acquired of the D. texanus, as observed in the Laguna de Términos, was that they are sexually mature at sizes as small as five millimeters wide. That’s a little more than an eighth of an inch on a ruler, barely a thumbnail’s width. [7]
For another Xanthid crab called Neopanope sayi, there is a bit more information on the matter. For the males of their species, the reproductive system consists of the tests, vasa deferentia, penes, and pleopods. “Nonmotile spermatozoa” leave the testes as individual cells, which are encapsulated within the anterior vasa deferentia. The spermatophores that result are transparent, delicate sphere about 0.2 millimeters in diameter. Spermatophores contain several hundred gametes that are stored in the median vasa deferentia until the males release them to fertilize a female’s egg. [8]
The females of the Neopanope sayi have a vagina, vulva, and two-lobed ovaries: one extending above their hepatopancreas and the other along the side of their digestive tract. Just before the females begin releasing their eggs into the water (spawning), their ovaries contain a large number of dark green eggs. When these species copulates, the males’ spermatophores are pumped by a “piston-like” motion of a pleopod into the gonopod, which are likely transferred to the females’ vagina. [8]
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period.
The Japanese spider crab is a species of marine crab that lives in the waters around Japan. It has the largest known leg-span of any arthropod. It goes through three main larval stages along with a prezoeal stage to grow to its great size.
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.
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:
Metanephrops challengeri is a species of slim, pink lobster that lives around the coast of New Zealand. It is typically 13–18 cm (5–7 in) long and weighs around 100 g (3.5 oz). The carapace and abdomen are smooth, and adults are white with pink and brown markings and a conspicuous pair of long, slim claws. M. challengeri lives in burrows at depths of 140–640 m (460–2,100 ft) in a variety of sediments. Although individuals can live for up to 15 years, the species shows low fecundity, where small numbers of larvae hatch at an advanced stage.
Hemigrapsus crenulatus, the hairy-handed crab or papaka huruhuru, is a marine crab of the family Varunidae, endemic to the New Zealand coast, although a taxon in Chile may be conspecific. It is an intertidal species with semi-terrestrial tendencies. They are named by their characteristic setae, or patches of thick hair, on the chelipeds and legs. They can range from green to brown in coloration. Adult crabs are generally 2–4 cm (0.8–1.6 in) wide at the carapace, although the smallest mature crabs can be around just 1 cm (0.4 in) wide. and are able to survive and reproduce in environments of widely varying salinities.
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.
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.
Xantho hydrophilus, the furrowed crab or Montagu's crab, is a species of crab from the family Xanthidae. It is yellowish-brown and grows to a carapace width of 70 mm (2.8 in). It is a nocturnal omnivore that lives in shallow marine waters from western Scotland to the Cape Verde Islands.
Guinotellus melvillensis is a species of crabs in the family Xanthidae, the only species in the genus Guinotellus. It is a benthic crab with an ovate carapace within the subfamily Euxanthinae.
Cryptolithodes typicus, often referred to as the butterfly crab or the turtle crab, is a species of lithodid crustacean native to coastal regions of the northeastern Pacific Ocean, ranging from Amchitka Island, Alaska to Santa Rosa Island, California.
Oregonia gracilis, commonly known as the graceful decorator crab, is a species of crab belonging to the family Oregoniidae. Like other decorator crabs it habitually attaches other organisms to its back. The sessile organisms are attached to hooked setae that act as a sort of velcro attachment. This decoration provides visual and chemical camouflage thus reducing predation risk. Pacific halibut are a major predator of O. gracilis. Other predators include octopus and sea otters. The main food source of O. gracilis is floating kelp and algae that they capture utilizing a waiting strategy in order to maintain cryptosis.
Dyspanopeus sayi is a species of mud crab that is native to the Atlantic coast of North America. It has also become established outside its native range, living in Swansea Docks since 1960, the Mediterranean Sea since the 1970s, the North Sea since 2007 and the Black Sea since 2010. It can reach a carapace width of 20 mm (0.8 in), and has black tips to its unequal claws. It feeds on bivalves and barnacles, and is in turn eaten by predators including the Atlantic blue crab, Callinectes sapidus. Eggs are produced from spring to autumn, the offspring reach sexual maturity the following summer, and individuals can live for up to two years. The closest relative of D. sayi is D. texanus, which lives in the Gulf of Mexico; the two species differ in subtle features of the genitalia and the last pair of walking legs.
Dyspanopeus is a genus of crabs in the family Xanthoidea, comprising two species:
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.
Portunus sayi, the sargassum swimming crab, is a species of pelagic crab in the family Portunidae. It is found in the western Atlantic Ocean and the Caribbean Sea where it makes its home among floating mats of Sargassum seaweed. It was named in honour of the American naturalist Thomas Say.
Ocypode africana, commonly known as the African ghost crab, is a species of ghost crabs native to the eastern Atlantic coast of western Africa, from Mauritania to Namibia. They are medium-sized ghost crabs reaching carapace width of 3.4 cm (1.3 in). They can vary in coloration from pinkish to dark grey. They are one of only two ghost crab species found in the eastern Atlantic. However, African ghost crabs can easily be distinguished from tufted ghost crabs by the absence of long tufts of hair on the tip of their eyestalks.
Charybdis hellerii, the Indo-Pacific swimming crab or spiny hands is a species of crab from the swimming crab family, the Portunidae. Its native range covers the Indian and Pacific Oceans but it has been introduced to the western Atlantic and has invaded the Mediterranean. It is a commercially exploited species in south-east Asia.
Loxothylacus panopaei is a species of barnacle in the family Sacculinidae. It is native to the Gulf of Mexico and the Caribbean Sea. It is a parasitic castrator of small mud crabs in the family Panopeidae, mostly in the Gulf of Mexico, the Caribbean Sea and the eastern Atlantic Ocean.