| Scotoplanes | |
|---|---|
 | |
 | |
| Scotoplanes globosa | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Holothuroidea |
| Order: | Elasipodida |
| Family: | Elpidiidae |
| Genus: | Scotoplanes Théel, 1882 [1] |
| Species | |
Scotoplanes is a genus of deep-sea sea cucumbers of the family Elpidiidae. Its species are commonly known as sea pigs.
Members of the Elpidiidae have particularly enlarged tube "feet" that have taken on a leg-like appearance, using water cavities within the skin to inflate and deflate thereby causing the appendages to move. [2] These appendages are different from the normal tube feet of the broader order of Elasipodida due the replacement of ampullae with dermal cavities to account for the larger size of the Elpidiidae tube feet. Scotoplanes move through the top layer of seafloor sediment and disrupt both the surface and the resident infauna as it feeds. [3] This type of movement is thought to be an adaptation to life on the soft floor of the deep-sea. These creatures, however, are able to swim when disturbed. Some species of Scotoplanes are benthopelagic and spend plenty of time in the water column. A frontal lobe as well as two anal lobes propel the sea pig through the water. Their tentacles help detect their surroundings while moving. [4]
Scotoplanes live on deep ocean bottoms, specifically on the abyssal plain in the Atlantic, Pacific and Indian Oceans, typically at depths of over 1,200 to 5,000 meters (3,900 to 16,400 feet) [5] [6] Some related species can be found in the Antarctic. Scotoplanes (and all deep-sea holothurians) are deposit feeders and obtain food by extracting organic particles from deep-sea mud. Scotoplanes globosa has been observed to demonstrate strong preferences for rich, organic food that has freshly fallen from the ocean's surface [7] and uses olfaction to locate preferred food sources such as whale corpses. [8] Scotoplanes, like many sea cucumbers, often occur in huge densities, sometimes numbering in the hundreds when observed. Early collections have recorded groups of up to 300-600 individuals. Sea pigs are also known to host different parasitic invertebrates, including gastropods (snails) and small tanaid crustaceans. [9]
Scotoplanes, like other sea cucumbers, host parasitic and commensal organisms. For example, it provides a shelter to juvenile crabs, Neolithodes diomedeae . It is known that such relationship benefits the crabs because they can reduce risks of predation when they are under the shelter. [10]
Scotoplanes are known to exhibit behavioral patterns of aggregation, where large numbers will aggregate either to feed or mate. [11]
Scotoplanes can grow to 4 to 6 inches (10 to 15 centimeters) in length. [12] They are bilaterally symmetrical with six pairs of tube feet, which are largest at mid-body and smallest near the anus. Scotoplanes also have ten buccal tentacles lining the oral cavity.
Scotoplanes are tiny and have their own defence mechanism to protect themselves from predators. Their skin contains a toxic chemical called holothurin which is poisonous to other creatures. They have external appendages which include tube feet, dorsal papillae, and buccal tentacles.
Like all echinoderms, Scotoplanes have a poorly developed respiratory system and they breathe from their anus. This refers to the lack of a respiratory tree. Their bodies are made for the deep seas and bringing them too close to the surface would cause them to disintegrate. [13] Also similar to other echinoderms is Scotoplanes nervous system, which consists of a network of nerves without ganglia.
Scotoplanes have unique reproductive systems that consist of one gonad in both female and male organisms. This means one ovary in females and one testis in males. This is different from most echinoderms. Also unique from most elasipodids is that active gametogenesis was observed in both females and males, pointing to a different reproduction strategy in Scotoplanes.
Similar to other echinoderms, Scotoplanes have a water vascular system. The dorsal papillae are similar histologically to Scotoplanes' tube feet, as both contain a large muscular water vascular canal in the center. Hydraulic pressure in these canals are responsible for the efficacy of the vascular system. [14]
The genus includes the following species: [15]
A study done provides histologic findings that these deep-sea dwelling sea pigs are similar to other holothuroidea, though there are few notable differences: most holothurians are sexually dioecious with sexes in separate individuals. Unlike other echinoderms, holothuroids possess only a single gonad. The water vascular system of holothuians is similar to other echinoderms, except the madreporite opens in the perivisceral coelom instead of in the external body wall. [16] In male Scotoplanes their aboral intestines have protozoa inside these cyst cavities. [16]
An echinoderm is any member of the phylum Echinodermata. The adults are recognisable by their radial symmetry, or pentamerous symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian.
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.
Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. They are found on the sea floor worldwide. The number of known holothurian species worldwide is about 1,786, with the greatest number being in the Asia-Pacific region. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, namako, bêche-de-mer, or balate. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter, after which bacteria can continue the decomposition process.
King crabs are a taxon of decapod crustaceans that are chiefly found in cold seas. Because of their large size and the taste of their meat, many species are widely caught and sold as food with the most common being the red king crab.
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.
Elasipodida is an order of sea cucumbers. They have numerous appendages, including conical papillae and leaf-like tentacles. Although many species are benthic, a number are pelagic, and may have their appendages modified to form sails or fins. Most members of the order inhabit deep-sea environments, such as the species of the genus Enypniastes.
Neolithodes is a genus of king crabs, in the family Lithodidae. They are found in all major oceans, both in high and low latitudes. Although there are records from water as shallow as 124 m (407 ft) in cold regions, most records are much deeper, typically 700–2,000 m (2,300–6,600 ft), with the deepest confirmed at 5,238 m (17,185 ft). They are fairly large to large crabs that typically are reddish in color and spiny, although the size of these spines varies depending on species.
Lissocarcinus orbicularis, common names sea cucumber crab, red-spotted white crab, and harlequin crab is a species of crab in the family Portunidae. This species gains one of its names from its close-knit relationship with holothuroids, the sea cucumbers. L. orbicularis should not be confused with L. laevis, a similar species of swimming crab, or Camposcia retusa, both of which are also commonly referred to as the harlequin crab. L. orbicularis displays numerous morphological and social adaptations for feeding and has a large distribution throughout the Indo-West Pacific.
Xyloplax medusiformis is a sea daisy, a member of an unusual group of marine taxa belonging to the phylum Echinodermata. It is found at bathyal depths in waters around New Zealand. It was first described in 1986 by Baker, Rowe and Clark and is the type taxon of the genus Xyloplax. Its generic name derives from the Greek "xylo" meaning wood and its specific name was chosen because its morphology superficially resembles that of a cnidarian medusa.
Elpidiidae is a family of deep-sea sea cucumbers.
Peniagone vitrea is a species of deep-sea swimming sea cucumber in the family Elpidiidae. It is a detritivore and is found in the northern Pacific Ocean at abyssal depths. It was first described by the Swedish zoologist Hjalmar Théel in 1879, being one of the many deep sea animals discovered during the Challenger expedition of 1872–1876.
Scotoplanes globosa, commonly known as the sea pig, is a species of sea cucumber that lives in the deep sea. It was first described by Hjalmar Théel, a Swedish scientist. Scotoplanes globosa, along with numerous other sea cucumbers were discovered by Théel during an expedition on HMS Challenger between the years of 1873-1876. Scotoplanes globosa was officially described in 1882, 6 to 9 years after its first sighting. Scotoplanes globosa is most closely related to the genus Peniagone.
Neolithodes agassizii is a species of king crab native to the Western Atlantic. They live at depths of 200–1,900 metres (660–6,230 ft), and have been found as far south as Rio de Janeiro, as far north as latitude 36°, and near the Equator. It has been found in the southwestern Caribbean Sea as well as the Gulf of Mexico.
Neolithodes yaldwyni is a species of king crab which is found in the Ross Sea from depths of 124–1,950 metres (407–6,398 ft). It had previously been misidentified as Neolithodes brodiei, and it closely resembles Neolithodes capensis.
Neolithodes brodiei is a species of king crab which is native to New Zealand and its adjacent waters. It lives at a depth of 500–1,240 metres (1,640–4,070 ft) but is typically found within a depth of 950–1,150 metres (3,120–3,770 ft). It has a deep-red colour, and its carapace has many small spinules along with larger spines. It is classified as "Not Threatened" by the New Zealand Department of Conservation.
Neolithodes capensis is a species of king crab which is found in the Southern Ocean and the western Indian Ocean. It has been found to a depth of 660–3,200 metres (2,170–10,500 ft).
Neolithodes diomedeae is a species of king crab which is found in the eastern Pacific Ocean, the southwestern Atlantic Ocean, and the Bellingshausen and Scotia Seas in the Southern Ocean. They occur from 200 to 2,454 m.
Neolithodes nipponensis is a species of king crab which is found in Japan and Taiwan. It has been found at depths from 200–1,752 metres (656–5,748 ft).
Neolithodes duhameli is a species of king crab which is found in the Crozet Islands in the southwestern Indian Ocean from a depth of 620–1,500 metres (2,030–4,920 ft).
Holothuria (Platyperona) difficilis is a species of sea cucumber in the family Holothuriidae. Holothuria comes from Latin but is originally taken from Greek. Its meaning is a plantlike animal whose origin is uncertain.
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Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.Ruhl, Henry A., and Kenneth L. Smith, Jr. "Go to Science." Science Magazine: Sign In. Science., 23 July 2004. Web. 1 May 2015. [1]