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Neuropodia
In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; : 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, 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 notochaetae respectively), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctonoe Sp
''Arctonoe'' is a genus of worms in the family Polynoidae. They are commonly known as "scale worms". Members of this genus predominantly occur in shallow (50 metres or less) waters of the north-eastern Pacific Ocean and often live as commensals of other marine invertebrates, frequently echinoderms but sometimes molluscs or other polychaetes. Description Arctonoe have long bodies, with 100 or more segments and numerous pairs of smooth translucent scales ( elytra) on several of the segments. The first segment ( prostomium), which contains the mouth, is rounded and smooth; on its side it has antennae pointing away from the body. Parapodia are found along the body with both dorsal (notopodial) and ventral (neuropodial) acicula penetrating epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L Oculatus Para Wscale
L, or l, is the twelfth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''el'' (pronounced ), plural ''els''. History Lamedh may have come from a pictogram of an ox goad or cattle prod. Some have suggested that it represents a shepherd's staff. Typographic variants In most sans-serif typefaces, the lowercase letter ''ell'' , written as the glyph , may be difficult to distinguish from the uppercase letter "eye" (written as the glyph ); in some serif typefaces, the glyph may be confused with the glyph , the digit ''one''. To avoid such confusion, some newer computer fonts (such as Trebuchet MS) have a finial, a curve to the right at the bottom of the lowercase letter ''ell''. Other style variants are provided in script typefaces and display typefaces. All these variants of the letter are encoded in Unicode as or , allowing presentation to be chosen accord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrus (biology)
In biology, a cirrus ( , : cirri, , from the Latin ''cirrus'' meaning a ''curl-like tuft or fringe'') is a long, thin structure in an animal similar to a tentacle but generally lacking the tentacle's strength, flexibility, thickness, and sensitivity. In the sheep liver fluke, for example, the ''cirrus'' is the worm's muscular penis and when not in use is retained within a ''cirrus sac'' or ''pouch'' near the animal's head. The same structure exists in the various Taenia (flatworm), ''Taenia'' species of tapeworm. In the Nereididae, clam worms, however, the cirrus is the tentacular process or growth on each of the feet (''parpodia''), either the ''dorsal cirrus'' or the ''ventral cirrus'', and has nothing to do with reproduction. Among the Polychaete, bristleworms, a cirrus is a tentacular growth near the head or notopodium containing sense organs and may be either dorsal, ventral, or lamellar. Among the Heteronemertea, ribbonworms, the ''caudal cirrus'' is a small thread-li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelida
The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains 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 Symmetry in biology, bilaterally symmetrical, Triploblasty, triploblastic, coelomate, invertebrate organisms. They also have Parapodium, parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistics, 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 Siboglinidae, Pogonophora, Echiura and Sipuncula, previ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epitoke Parapodium
Epitoky is a process that occurs in many species of polychaete marine worms wherein a sexually immature worm (the atoke) is modified or transformed into a sexually mature worm (the epitoke). Epitokes are pelagic morphs capable of sexual reproduction. Unlike the immature form, which is typically benthic (lives on the bottom), epitokes are specialized for swimming as well as reproducing. The primary benefit to epitoky is increased chances of finding other members of the same species for reproduction. There are two methods in which epitoky can occur: schizogamy and epigamy. Schizogamy Many species go through schizogamy, where the atoke uses asexual reproduction to produce buds from its posterior end. Each bud develops into an epitoke which, once fully formed, will then break off from the atoke and become free-swimming. Many genetically identical epitokes are formed in this way, thus allowing a higher chance of finding a mate of the same species and subsequent passing of genes to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplysiomorpha
The order Aplysiida, commonly known as sea hares (''Aplysia'' species and related genera), are medium-sized to very large opisthobranch gastropod molluscs with a soft internal shell made of protein. These are marine gastropod molluscs in the superfamilies Aplysioidea and Akeroidea. The common name "sea hare" is a direct translation from , as the animal's existence was known in Roman times. The name derives from their rounded shape and from the two long rhinophores that project upward from their heads and that somewhat resemble the ears of a hare. Taxonomy Many older textbooks and websites refer to this suborder as "Aplysiida". The original author Paul Henri Fischer described the taxon Aplysiida at unspecified rank above family. In 1925 Johannes Thiele established the taxon Aplysiida as a suborder. 2005 taxonomy Since the taxon Aplysiida was not based on an existing genus, this name is no longer available according to the rules of the ICZN. Aplysiida has been replace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosomata
Sea angels (clade Gymnosomata) are a large group of small free-swimming sea slugs, classified into six separate families. They are pelagic opisthobranchs in the clade Gymnosomata within the larger mollusc clade Heterobranchia. Sea angels were previously considered to be pteropods. Sea angels are also sometimes known as "sea butterflies" but this is potentially misleading because the family Clionidae is just one of the families within this clade, and the term "sea butterfly" is also applied to the shelled Thecosomata. Recent molecular data suggest the Gymnosomata form a sister group to the Thecosomata (other planktonic, weakly or nonmineralized gastropods), but this long-standing hypothesis has also had some recent detractors. Distribution These organisms have a wide geographic range, from polar regions, under sea ice, to equatorial (tropic) seas. From spring to autumn, sea angels live at a depth of 200 m in the Sea of Okhotsk. In winter, they migrate to the coast of north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thecosomata
The Thecosomata (collective/plural: ''thecosomes'', meaning "case/shell-body"), or sea butterflies, are a taxonomic suborder of small, pelagic, free-swimming sea snails known as holoplanktonic opisthobranch gastropod mollusks, in the order Pteropoda (also included within the informal group Opisthobranchia). Most pteropods have some form of calcified shell, although it is often very light, even translucent. The sea butterflies include some of the world's most abundant gastropod species; as their large numbers are an essential part of the ocean food chain, they are a significant contributor to the oceanic carbon cycle. Morphology Unlike other sea snails, or even land snails, sea butterflies float and swim freely through the ocean, traveling along with the currents. This has led to a number of evolutionary adaptations in their bodies, including complete or near-complete loss of the shell and the gill in several families. Their gastropodal foot has also taken the form of two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalaspidea
The order Cephalaspidea, also known as the headshield slugs and bubble snails, is a major taxon of sea slugs and bubble snails, marine (ocean), marine gastropod mollusks within the larger clade Euopisthobranchia. Bubble shells is another common name for these families of marine gastropods, some of which have thin bubble-like shells. This clade contains more than 600 species. Members of this worldwide clade used to be considered the most ancestral of the opisthobranchs, but now they are considered as derived and specialized members of the Euthyneura Spengel, 1881. Headshield slugs are the most morphologically diverse group of all the opisthobranchs. Anatomy The vast majority possess a shell, although it may be reduced or internal. They have a well-developed headshield, a characteristic broadening at the head, which is used to plow beneath the surface of the sand. This headshield prevents the sand entering the mantle cavity. There is a muscular foot with or without parapodia (f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Butterflies
The Thecosomata (collective/plural: ''thecosomes'', meaning "case/shell-body"), or sea butterflies, are a taxonomic suborder of small, pelagic, free-swimming sea snails known as holoplanktonic opisthobranch gastropod mollusks, in the order Pteropoda (also included within the informal group Opisthobranchia). Most pteropods have some form of calcified shell, although it is often very light, even translucent. The sea butterflies include some of the world's most abundant gastropod species; as their large numbers are an essential part of the ocean food chain, they are a significant contributor to the oceanic carbon cycle. Morphology Unlike other sea snails, or even land snails, sea butterflies float and swim freely through the ocean, traveling along with the currents. This has led to a number of evolutionary adaptations in their bodies, including complete or near-complete loss of the shell and the gill in several families. Their gastropodal foot has also taken the form of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. There are many thousands of species of sea snails and sea slug, slugs, as well as freshwater snails, freshwater limpets, land snails and slugs. The class Gastropoda is a diverse and highly successful class of mollusks within the phylum Mollusca. It contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Furongian, Late Cambrian. , 721 family (taxonomy), families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently neontology, extant living fossil, with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plakobranchus Ocellatus 3
''Plakobranchus'' is a genus of sea slugs, sacoglossans, marine opisthobranch gastropod mollusks in the family Plakobranchidae Plakobranchidae is a family (biology), family of sea slugs, marine (ocean), marine opisthobranch gastropod mollusks in the superfamily Plakobranchoidea. They superficially resemble nudibranchs but they are sacoglossans, members of the clade Sacog ....Gofas, S. (2012)''Plakobranchus'' van Hasselt, 1824.Accessed through: World Register of Marine Species on 2012-03-08 The author of the genus spelled the name originally as ''Plakobranchus'', but the spelling ''Placobranchus'' was a long time the prevailing usage, based on an incorrect subsequent spelling by Férussac (1824) in a translation of van Hasselt's work. Species Species within the genus ''Plakobranchus'' include: * '' Plakobranchus noctisstellatus'' Mehrotra, Caballer, C.M. Scott, Arnold, Monchanin & Chavanich, 2020 * '' Plakobranchus ocellatus'' van Hasselt, 1824 * '' Plakobranchus papua'' Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
