| Encope emarginata | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Echinoidea |
| Order: | Clypeasteroida |
| Family: | Mellitidae |
| Genus: | Encope |
| Species: | E. emarginata |
| Binomial name | |
| Encope emarginata (Leske, 1778) | |
Encope emarginata, a notched sand dollar, is a marine echinoid ranging the western Atlantic ocean. They are best known for their bioturbation in the sediment, relationship with crabs, and their widespread distribution.
Encope emarginata has a thick test, or shell, that often remains intact and preserved. [1] Tests are oval-shaped, centrally domed, typically greenish-brown colored, and have 6 lunules, or notches, as well as large bowed petaloids [2] Young E. emarginata can be mistaken for its sibling, E. michelini, because of the presence of open lunules as juveniles, although closed as adults. [3]
Mostly found in subtropical and tropical waters of the Caribbean Sea, Gulf of Mexico, and southwestern Atlantic Ocean, E. emarginata ranges from Belize to Argentina. [4] Common on the South America Atlantic coastline, they are one of the only extant echinoids found on the coast of Rio Grande do Sul (the other being Mellita quinquiesperforata ) and the only one south of the La Plata river. [5] Area inhibited by Encope emarginata is below the action of the normal wave regime, thus the fossils of this species is only truly disturbed during extreme coastal weather. [5]
Encope emarginata inhabits sandy, muddy sediments of coastal waters. [4] Although a marine species, [6] they have also been found in estuaries and river mouths. [7] The waters they live in are typically shallow, as deep as 20 meters. [8]
These sand dollars were originally named Echinodiscus emarginatus, [9] but have since been transferred to the Encope genus within the Mellitidae family. [6] Encope is thought to be the most diverse genus among sand dollars, containing 7 extant species. [1] Fossils can be dated back to the Pliocene or Pleistocene, up to 5 million years ago. [1]
There is ongoing research suggesting that two populations of E. emarginata may emerge as separate species as a result of a barrier created by upwelling, a process known as allopatric speciation. [4]
Encope emarginata is well-known for its bioturbation within the sediment, especially its effect on the spatial distributions of phytoplankton and other small benthic organisms. Moving at a maximum rate of 15 cm per hour, these sand dollars typically work through surface-layer sediments. E. emarginata has shown to have significant impacts on the concentrations of Chlorophyll-a within the sediment, as well as causing a greater variance in microphytobethic and meiofaunal populations due to the sand dollars' foraging behaviors. The bioturbation of this echinoid is thought to create top-down effects, enhancing sediment heterogeneity and maintaining benthic biodiversity. [10]
Genus Dissodactylus are commensal or parasitic crabs found to live on the bodies of irregular echinoids, such as E. emarginata. There is ongoing debate whether the size of E.emarginata influences the number of crabs found on it, where one study found a positive correlation [11] and another found no relationship. [12] The crabs are thought to consume the spines of the sand dollar, but additional research is necessary to determine if the Dissodactylus are truly parasitic. [11]
Sea urchins are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin are distributed on the seabeds of every ocean and inhabit every depth zone from the intertidal seashore down to 5,000 meters. The spherical, hard shells (tests) of sea urchins are round and covered in spines. Most urchin spines range in length from 3 to 10 cm, with outliers such as the black sea urchin possessing spines as long as 30 cm (12 in). Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals, and humans.
Sand dollars are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are known as sea biscuits. Sand dollars can also be called "sand cakes" or "cake urchins".
Peripatus is a genus of velvet worms in the Peripatidae family. The name "peripatus" is also used to refer to the Onychophora as a whole, although this group comprises many other genera besides Peripatus. The genus Peripatus is found in Central America, the Caribbean and northern South America. Velvet worms in this genus may have as few as 24 or 25 pairs of legs or as many as 36 leg pairs. This genus is viviparous, with mothers supplying nourishment to their embryos through a placenta.
Diadema setosum is a species of long-spined sea urchin belonging to the family Diadematidae. It is a typical sea urchin, with extremely long, hollow spines that are mildly venomous. D. setosum differs from other Diadema with five, characteristic white dots that can be found on its body. The species can be found throughout the Indo-Pacific region, from Australia and Africa to Japan and the Red Sea. Despite being capable of causing painful stings when stepped upon, the urchin is only slightly venomous and does not pose a serious threat to humans.
Cattleya trianae, also known as Flor de Mayo or "Christmas orchid", is a plant of the family Orchidaceae. It grows as an epiphytic orchid, with succulent leaves, endemic to Colombia where it was nominated as the national flower in November 1936. That year, the National Academy of History of Argentina asked the Latin American countries to participate in an exhibition with the representative flowers of each country. The Colombian government gave the botanist Emilio Robledo the task to designate the most representative flowering plant of the country.
Urobatis is a genus of the family Urotrygonidae. These rays live in Costa Rica, Mexico, the Bahamas, El Salvador, Honduras, Guatemala, Nicaragua, Colombia, Venezuela, Panama, Trinidad and Tobago, Barbados, Grenada, Saint Vincent and the Grenadines, Saint Lucia, Martinique, Dominica, Guadeloupe, Montserrat, Antigua and Barbuda, Belize, Puerto Rico, Saint Kitts and Nevis, Anguilla, Dominican Republic, Haiti, Jamaica, Cuba, Cayman Islands, Virgin Islands, Turks and Caicos Islands, French Guiana, Guyana, Suriname, Chile, Peru, Ecuador and the United States.
Urobatis maculatus, known as the spotted round ray or Cortez round stingray, is a species of round ray, within the genus Urobatis, and of the family Urotrygonidae. It is endemic to Mexico, with its natural habitats being shallow seas, subtidal aquatic beds, coral reefs, estuarine waters, intertidal marshes, and coastal saline lagoons.
Canthonella is a genus of Scarabaeidae or scarab beetles.
Holothuria atra, commonly known as the black sea cucumber or lollyfish, is a species of marine invertebrate in the family Holothuriidae. It was placed in the subgenus Halodeima by Pearson in 1914, making its full scientific name Holothuria (Halodeima) atra. It is the type species of the subgenus.
Echidna nocturna is a moray eel found in the eastern Pacific Ocean, in the Gulf of California and around Peru and the Galapagos Islands. It was first named by Cope in 1872, and is commonly known as the freckled moray or the palenose moray. It was discovered that Echidna nocturna and Muraena acutis are the same species.
Spiraxis is a genus of predatory air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Spiraxidae.
Heliophora orbicularis, also known as the West African Sand Dollar, is a small sand dollar in to the family Rotulidae, and the only species in the genus Heliophora. It, and other members of Rotulidae have been found in West African marine strata from the Late Miocene onward. Like the related Rotula, it is still extant.
Mongeperipatus solorzanoi, the Solórzano's velvet worm, is the largest known species of velvet worm and a member of the Peripatidae family. Like other Neotropical peripatid velvet worms, this species is viviparous, with mothers supplying nourishment to their embryos through a placenta.
Macroperipatus ohausi is a species of velvet worm in the Peripatidae family. Females of this species have 27 or 28 pairs of legs. The type locality is Rio de Janeiro, Brazil.
Holothuria grisea, the gray sea cucumber, is a mid-sized coastal species of sea cucumber found in shallow tropical waters of the Atlantic Ocean from Florida to Southern Brazil and West Africa. They have a variety in color and can range from red to more yellowish with brown markings. They are also a food source for local and international markets with the majority of harvesting taking place in Brazil. This species is currently not over-fished and is not endangered or threatened.
Megapitaria squalida, the chocolate clam, is a species of bivalve mollusc in the family Veneridae. It was first described to science by George Brettingham Sowerby, a British conchologist, in 1835. The type specimen was collected by Hugh Cuming.
Hawaiioscia nicoyaensis is a species of woodlouse from Costa Rica. Its specific epithet is derived from the location of its type locality along the Gulf of Nicoya. It is the only known member of its genus to be found on a continent rather than a pacific island and the only one to be littoral halophilic. Furthermore, it is the only extant member of its genus not to be restricted to caves.
Ophiomusa is a genus of echinoderms belonging to the family Ophiolepididae that includes: sea urchins, sand dollars and sea cucumbers. Ophiurida are similar to starfish; they both have a central disc and five arms sprouting from the disc. One of the main distinguishing factors of an Ophiuroid is its arms; the arms of an Ophiurida are longer, thinner, and distinctly separated in comparison to those of a sea star.
Mongeperipatus kekoldi is a large species of velvet worm in the Peripatidae family. Males of this species have 32 or 33 pairs of legs and females have 37 to 39, but these numbers are based on only a few specimens. The large known specimen, an adult female, was 18 cm (7.1 in) long. This species is endemic to Costa Rica where it lives near streams in forests and semi-altered habitats.
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