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Holothuroidea
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. Sea cucumbers are found on the sea floor worldwide. The number of holothurian () species worldwide is about 1,717, 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. Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial 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. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synallactida
Synallactida is a rankless clade of sea cucumbers, but is referred to as an order. Taxa within Synallactida were previously classified in an order called Aspidochirotida, which was determined to be polyphyletic in 2017. List of families Synallactida includes over 130 species in three extant families and two extinct genera: * Deimatidae Théel, 1882 – 3 genera * Stichopodidae Haeckel, 1896 – 9 genera * Synallactidae The Synallactidae are a family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being o ... Ludwig, 1894 – 12 genera * Genus †'' Collbatothuria'' Smith & Gallemí, 1991 * Genus †'' Tribrachiodemas'' Reich, 2010 Image:Parastichopus californicus.jpg, '' Apostichopus californicus'' Image:Australostichopus mollis P1222859.JPG, '' Australostichopus mollis'' Image:Isostichopus badionotus.jpg, '' Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagothuriidae
Pelagothuriidae is a family of deep-sea swimming sea cucumbers. They are somewhat unusual in appearance, in comparison with other sea cucumbers, having numerous appendages, including conical papillae and leaf-like tentacles. Most of them are benthopelagic, which means that they are able to swim for a time from the bottom : the species ''Pelagothuria natatrix'' is the only true pelagic holothurian (and echinoderm, to date) ; it looks like a jellyfish. Most members of the order inhabit deep-sea environments, like ''Enypniastes''. Classification Family: Pelagothuriidae * genus ''Enypniastes ''Enypniastes'' is a genus of deep-sea sea cucumber. It is monotypic, being represented by the single species ''Enypniastes eximia''. Due to its unique appearance, the species has been dubbed the headless chicken fish, headless chicken monster, ...'' Théel, 1882 * genus '' Pelagothuria'' Ludwig, 1893 References * * Notes Echinoderm families {{Holothuroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apodida
Apodida is an order of littoral to deep-sea, largely infaunal holothurians, sea cucumbers. This order comprises three families, 32 genera and about 270 known species, called apodids, "without feet". Characteristics These sea cucumbers are vagile holothurians with an elongated shape (up to 3 meters for ''Synapta maculata''), worm or snake-like. Their shape is adapted for burrowing through the sediment, sometimes in a fashion similar to earthworms. Their mouth is surrounded with 10-25 pinnate or peltate tentacles. The absence of tube feet gives the order its name, ''Apodida'' meaning ''without feet'' : they move by crawling on the sediment, hence they need flat bottoms with few current. Members of this order have a circum-oral ring and tentacles, but do not have tube feet or radial canals. They also lack the complex respiratory trees found in other sea cucumbers, and respire and excrete nitrogenous waste through their skin. The ossicles, minute calcareous plates embedded in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrochirotida
Dendrochirotida are an order of sea cucumbers. Members of this order have branched tentacles and are suspension feeders. Examples include '' Thyonella'' and '' Cucumaria''. Characteristics Holothurians in this order are characterised by ten to thirty much branched tentacles which are sometimes digitate. They also have ring structures composed of ten calcareous plates circling the pharynx. They have both retractor and introvert muscles which means they can retract the tentacles into the mouth when not feeding. The body wall is either firm with large ossicles or of a soft consistency with few ossicles. In some genera the animals attach themselves to hard surfaces but in others they burrow into soft sediments. Prey is captured by the sticky tentacles and transferred to the mouth. The larvae are lecithotrophic, not feeding on plankton but surviving only on materials already present in the eggs until they settle and become juveniles. Taxonomy Order: Dendrochirotida * family Cucumariida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasipodida
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''. Classification The following families are recognised in the order Elasipodida: * family Elpidiidae Théel, 1882 * family Laetmogonidae Ekman, 1926 * family † Palaeolaetmogonidae Reich, 2012 * family Pelagothuriidae Ludwig, 1893 * family Psychropotidae Théel, 1882 Image:Pelagothuria natatrix.jpg, The only true pelagic echinoderm known to date : ''Pelagothuria natatrix'' (here close to the Galapagos). Image:Expl0790 - Flickr - NOAA Photo Library.jpg, ''Benthodytes sp.'' Image:Scotoplanes globosa and crab.jpg, ''Scotoplanes globosa'' (a.k.a. "sea pig", family Elpidiidae) Image:Expl5475.jpg, A Pelagothuriidae Image:Expl5494.jpg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holothuriida
Holothuriida is an order of sea cucumbers. Taxa within the order Holothuriida were previously classified in the order Aspidochirotida, which was determined to be polyphyletic in 2017. Some taxa were also reclassified into the clades Synallactida and Persiculida. Description and characteristics Species of the order Holothuriida are distinguished from other sea cucumbers by the presence of flattened, often leaf-like tentacles, but without the other large appendages found in the related order Elasipodida. They do not have introvert or retractor muscles. The tube feet often form a clearly demarcated sole. They have 15-30 shield-shaped retractile tentacles surrounding their mouths. The body wall is thick and leathery and contains ossicles, including some table-shaped ones. They have respiratory trees for gas exchange. The mesentery of the posterior loop of their gut is attached to the right ventral interradius. The muscles that run longitudinally down the body are arranged into five ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molpadida
Molpadida is an order of sea cucumbers. The body shape is fusiform and unlike other sea cucumbers, their hind body is narrowed to form a distinct tail. Although they possess tentacles around the mouth derived from the water vascular system, they have no true tube feet, and are therefore believed to be related to the Apodida. They have fifteen much branched tentacles and a stout body. They have tentacle ampullae and respiratory trees present, a kind of water lung attached to the cloaca. The ossicles The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ..., minute calcareous plates embedded in the skin and characteristic of each species, take the form of tables, anchors, fusiform rods and perforated plates but never wheels. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persiculida
Persiculida is an order of sea cucumbers. Taxa within the order Persiculida were previously classified in an order called Aspidochirotida, which was determined to be polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ... in 2017. References Echinoderm orders {{Holothuroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Feet
Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on brittle stars, and have only a feeding function in feather stars. They are part of the water vascular system. Structure and function Tube feet function in locomotion, feeding, and respiration. The tube feet in a starfish are arranged in grooves along the arms. They operate through hydraulic pressure. They are used to pass food to the oral mouth at the center, and can attach to surfaces. A starfish that is inverted turns one arm over and attaches it to a solid surface, and levers itself the right way up. Tube feet allow these different types of animals to stick to the ocean floor and move slowly. Each tube foot consists of two parts: the ampulla and the podium. The ampulla is a water-filled sac contained in the body of the animal that contain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ossicle (echinoderm)
Ossicles are small calcareous elements embedded in the dermis of the body wall of echinoderms. They form part of the endoskeleton and provide rigidity and protection. They are found in different forms and arrangements in sea urchins, starfish, brittle stars, sea cucumbers, and crinoids. The ossicles and spines (which are specialised sharp ossicles) are the only parts of the animal likely to be fossilized after an echinoderm dies. Formation Ossicles are created intracellularly by specialised secretory cells known as sclerocytes in the dermis of the body wall of echinoderms. Each ossicle is composed of microcrystals of calcite arranged in a three-dimensional lattice known as a stereom. Under polarized light the ossicle behaves as if it were a single crystal because the axes of all the crystals are parallel. The space between the crystals is known as the stroma and allows entry to sclerocytes for enlargement and repair. The honeycomb structure is light but tough and collage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trepanging
Trepanging is the act of collection or harvesting of sea cucumbers, known in Indonesian as ''trepang'', Malay těripang, and used as food. The collector, or fisher, of ''trepang'' is a trepanger. Trepanging is comparable to clamming, crabbing, lobstering, musseling, shrimping and other forms of "fishing" whose goal is the acquisition of edible invertebrates rather than fish. History To supply the markets of Southern China, Makassarese trepangers traded with the Aboriginal Australians of Arnhem Land from at least the 18th century or likely prior. This Makassan contact with Australia is the first recorded example of interaction between the inhabitants of the Australian continent and their Asian neighbours. This contact had a major impact on the Indigenous Australians. The Makassarese exchanged goods such as cloth, tobacco, knives, rice and alcohol for the right to trepang coastal waters and employ local labour. Makassar pidgin became a ''lingua franca'' along the north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
