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Disconatis
''Disconatis'' is a genus of marine annelids in the family Polynoidae (scale worms). The genus includes two species which are both commensal with other kinds of marine Annelida and occur in Australia and New Zealand.Source reference(s) for description: Hanley, J. Russell and Burke, Melanie 1988. A new genus and species of commensal scaleworm (Polychaeta: Polynoidae). The Beagle, Records of the Northern Territory Museum of Arts and Sciences, 5(1): 5–15. Species As at September 2020, there are two species within ''Disconatis'': *'' Disconatis accolus'' *'' Disconatis contubernalis'' Description ''Disconatis'' is a long-bodied genus with up to 152 segments and 22–80 pairs of elytra which are small and translucent; the first pair are much larger than the following elytra. The lateral antennae are inserted ventral to the median antenna. The notopodium is vestigial and notochaetae are absent. The neuropodium is rounded and the neurochaetae are uinidentate but have serratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disconatis Contubernalis
''Disconatis contubernalis'' is only known from Australia where it is commensal in the tubes of marine annelids of the family Maldanidae.Hanley, J. Russell and Burke, Melanie 1988. A new genus and species of commensal scaleworm (Polychaeta: Polynoidae). The Beagle, Records of the Northern Territory Museum of Arts and Sciences, 5(1): 5–15. Description ''Disconatis contubernalis'' has up to 152 segments and 22–80 pairs of elytra; the first pair are much larger than the following elytra which have a few large papillae on the surface. ''Disconatis conturbernalis'' which has large papillae on the elytra but a smooth body, in contrast with the other species in the genus, '' Disconatis accolus'', which has smooth elytra but with minute papillae on the dorsal surface of the body. The lateral antennae are inserted ventral to the median antenna. Notopodia are vestigial and notochaetae are absent, while the neuropodium is rounded and the neurochaetae are unidentate but have serrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disconatis Accolus
''Disconatis accolus'' is only known from New Zealand where it is commensal in the tubes of marine annelids of the family Arenicolidae.Estcourt, I. N. 1967. Burrowing polychaete worms from a New Zealand estuary. Transactions of the Royal Society of New Zealand, Ser. Zoology, 9(7): 65–78. Description ''Disconatis accolus'' is known from a single specimen with 152 segments and 76 pairs of elytra; the first pair are much larger than the following. It has smooth elytra but with minute papillae on the dorsal surface of the body, in contrast with the other species in the genus, ''Disconatis contubernalis'' which has large papillae on the elytra but a smooth body. The lateral antennae are inserted ventral to the median antenna. Notopodia are vestigial and notochaetae are absent. The neuropodia are rounded and the neurochaetae are unidentate but have serrations on the convex side. Biology and ecology ''Disconatis accolus'' has a commensal relationship with the annelid ''Abareni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polynoidae
Polynoidae is a family of marine Polychaete worms known as "scale worms" due to the scale-like elytra on the dorsal surface. Almost 900 species are currently recognised belonging to 9 subfamilies and 167 genera. They are active hunters, but generally dwell in protected environments such as under stones. The group is widely distributed from shallow intertidal waters to hadal trenches. They are the most diverse group of polychaetes in terms of genus number and second most diverse in terms of species number which is almost 8% of all segmented worm species. Description Most Polynoidae species are short and flattened, but can reach as much as 20 cm in length and 10 cm width in ''Eulagisca gigantea'' and ''Eulagisca uschakovi''. Individuals are usually covered almost entirely by elytra, which can be shed and regenerated in many species. The elytra of some species are faintly bioluminescent, and leave glowing traces around the mouthparts of their predators, making those preda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelids
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commensal
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit from each other; amensalism, where one is harmed while the other is unaffected; parasitism, where one is harmed and the other benefits, and parasitoidism, which is similar to parasitism but the parasitoid has a free-living state and instead of just harming its host, it eventually ends up killing it. The commensal (the species that benefits from the association) may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the remoras that ride attached to sharks and other fishes. Remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country by area, covering . New Zealand is about east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The country's varied topography and sharp mountain peaks, including the Southern Alps, owe much to tectonic uplift and volcanic eruptions. New Zealand's capital city is Wellington, and its most populous city is Auckland. The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and then developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. In 1840, representatives of the United Kingdom and Māori chiefs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elytron (Annelida)
In annelids, elytra (; from Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ... ἔλυτρον "sheath, cover"; singular: elytron ) are shield-like scales that are attached dorsally, one pair on each of a number of alternating segments and entirely or partly cover the dorsum. Elytra are modified dorsal cirri, and their number, size, location, and ornamentation are important taxonomic characters. The basal part of the elytra is known as the elytrophore; if (as is often the case) elytra are lost their presence is indicated by the elytrophore which is still present and visible. Annelids possessing elytra are also known as "scale worms". Possession of elytra is characteristic of the annelid suborder Aphroditiformia. Gallery File:Eunoe leiotentaculata lower res.jpg, A '' Eunoe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapodium
In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; plural: parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed lateral outgrowths that bear the chaetae. In several groups of sea snails and sea slugs, 'parapodium' refers to lateral fleshy protrusions. __TOC__ Annelid parapodia Most species of polychaete annelids have paired, fleshy parapodia which are segmentally arranged along the body axis. Parapodia vary greatly in size and form, reflecting a variety of functions, such as gas exchange, anchorage, protection and locomotion. General description Parapodia in polychaetes can be uniramous (consisting of one lobe or ramus) but are usually biramous (two lobes or rami). In the latter case, the dorsal lobes are called notopodia and the ventral lobes neuropodia. Both neuropodia and notopodia may possess a bundle of chaetae (neurochaetae and notochaet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaeta
A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates such as arthropods). Polychaete annelids, ('polychaeta' literally meaning "many bristles") are named for their chaetae. In Polychaeta, chaetae are found as bundles on the parapodia, paired appendages on the side of the body. The chaetae are epidermal extracellular structures, and clearly visible in most polychaetes. They are probably the best studied structures in these animals. Use in taxonomy and identification The ultrastructure of chaetae is fundamentally similar for all taxa but there is vast diversity in chaetal morphology. Moreover, chaetae bear precise characters for determination of species and taxonomic assessment. The shape, absolute and relative size, number, position, ornamentation and type are important taxonomic characters a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arenicolidae
Arenicolidae is a family of marine polychaete worms. They are commonly known as lugworms and the little coils of sand they produce are commonly seen on the beach. Arenicolids are found worldwide, mostly living in burrows in sandy substrates. Most are detritivores but some graze on algae. Description The arenicolids are characterised by an elongated cylindrical body separated into two or three distinct regions. The prostomium has no appendages or palps. There are one or two anterior segments without setae. On the other segments, all the setae are unbranched, including the capillary setae and the rostrate uncini. The notopodia are bluntly truncate and the neuropodia are elongated tori forming long transverse welts in some of the setigers. The notosetae have either a capillary function or act as limbs and the neurosetae are rostrate hooks. There are branchiae present on some of the setigers in the middle or posterior regions. Apart from the genus '' Branchiomaldane'', the lugwor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
