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Sternaspidae
Sternaspidae, commonly known as mud owls, are a family of marine polychaete worms with short swollen bodies. They have a global distribution and live buried in soft sediment at depths varying from the intertidal zone to . Description Members of this family have oval or dumbbell-shaped bodies with a small number of segments, the prostomium often being separated from the rest of the body by a narrower segment. The peristomium is reduced to lips. The first segment of the prostomium, bears the mouth but no antennae, palps or nuchal organ. The first three segments bear rows of chaetae (bristles) and the next seven segments bear lateral bundles of tiny chaetae. The parapodia present on each segment are biramous except for those near the posterior end of the body which are uniramous. On the ventral side of the posterior of the body there are two chitinised calcareous plates forming a shield, the margins of which are rimmed with bundles of capillary chaetae. A number of long, semi-coiled, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terebellida
Terebellida make up an order of the Polychaeta class, commonly referred to as "bristle worms". Together with the Sabellida, the Spionida and some enigmatic families of unclear taxonomic relationship (e.g. the Saccocirridae), they make up the subclass Canalipalpata, one of the three main clades of polychaetes. Like most polychaetes, almost all members of the ''Terebellida'' are marine organisms. Most are small, sessile detritivores (deposit feeders) which live in small tubes they build from mud or similar substrate, or burrow in the sand. Their central nervous system displays characteristic apomorphies. Systematics There is little consensus on the number of families. Some treatments accept as little as five, while other authors list over a dozen. Here, the more inclusive view of the Terebellida is followed, based on a major review of polychaete systematics. Cladistic studies have hitherto only analyzed a rather small proportion of polychaetes; hence it may be that so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychaete
Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the sandworm or clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe ''Nereus'' at the bottom of the Challenger Deep, the deepest known spot in the Earth's oceans. Only 168 species (less than 2% of all polychaetes) are known from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternaspis (polychaete)
''Sternaspis'' is a genus of annelids belonging to the family Sternaspidae. The genus has cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext .... Species: *'' Sternaspis affinis'' *'' Sternaspis africana'' *'' Sternaspis andamanensis'' *'' Sternaspis annenkovae'' *'' Sternaspis britayevi'' *'' Sternaspis buzhinskajae'' *'' Sternaspis chilensis'' *'' Sternaspis chinensis'' *'' Sternaspis costata'' *'' Sternaspis fossor'' *'' Sternaspis islandica'' *'' Sternaspis lindae'' *'' Sternaspis liui'' *'' Sternaspis londognoi'' *'' Sternaspis maior'' *'' Sternaspis maureri'' *'' Sternaspis nana'' *'' Sternaspis papillosa'' *'' Sternaspis piotrowskiae'' *'' Sternaspis princeps'' *'' Sternaspis radiata'' *'' Sternaspis rietschi'' *'' Sternaspis sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Register Of Marine Species
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialists on each group of organism. These taxonomists control the quality of the information, which is gathered from the primary scientific literature as well as from some external regional and taxon-specific databases. WoRMS maintains valid names of all marine organisms, but also provides information on synonyms and invalid names. It is an ongoing task to maintain the registry, since new species are constantly being discovered and described by scientists; in addition, the nomenclature and taxonomy of existing species is often corrected or changed as new research is constantly being published. Subsets of WoRMS content are made available, and can have separate badging and their own home/launch pages, as "subregisters", such as the ''World List ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food and air to the esophagus and larynx respectively. The flap of cartilage called the epiglottis stops food from entering the larynx. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system. (The conducting zone—which also includes the nostrils of the nose, the larynx, trachea, bronchi, and bronchioles—filters, warms and moistens air and conducts it into the lungs). The human pharynx is conventionally divided into three sections: the nasopharynx, oropharynx, and laryngopharynx. It is also important in vocalization. In humans, two sets of pharyngeal muscles form the pharynx and determine the shape of its lumen. They are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detritivore
Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, vertebrates and plants that carry out coprophagy. By doing so, all these detritivores contribute to decomposition and the nutrient cycles. They should be distinguished from other decomposers, such as many species of bacteria, fungi and protists, which are unable to ingest discrete lumps of matter, but instead live by absorbing and metabolizing on a molecular scale ( saprotrophic nutrition). The terms ''detritivore'' and ''decomposer'' are often used interchangeably, but they describe different organisms. Detritivores are usually arthropods and help in the process of remineralization. Detritivores perform the first stage of remineralization, by fragmenting the dead plant matter, allowing decomposers to perform the second stage of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the world ocean is conventionally divided."Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, plural ''coxae''), ''trochanter'', ''femur'' (plural ''femora''), ''tibia'' (plural ''tibiae''), ''tarsus'' (plural ''tarsi''), ''ischium'' (plural ''ischia''), ''metatarsus'', ''carpus'', ''dactylus'' (meaning finger), ''patella'' (plural ''patellae''). Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a ''Hox''-gene, could result in parallel gains of leg segments. In arthropods, each of the leg segments ... [...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 notoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
