|
Acoela
Acoela, or the acoels, is an order of small and simple invertebrates in the subphylum Acoelomorpha of phylum Xenacoelomorpha, a deep branching bilaterian group of animals, which resemble flatworms. Historically they were treated as an order of turbellarian flatworms. The etymology of "acoel" is from the Ancient Greek words (), the ''alpha privative'', expressing negation or absence, and (), meaning "cavity". This refers to the fact that acoels have a structure lacking a fluid-filled body cavity. Description Acoels are very small flattened worms, usually under in length, but some larger species, such as '' Symsagittifera roscoffensis'', may reach up to . They are bilaterally symmetric and microscopic. They are found worldwide in marine and brackish waters, usually having a benthic lifestyle, although some species are epibionts. Two species, ''Limonoposthia polonica'' and ''Oligochoerus limnophilus'', lives in freshwater. Members of the class Acoela lack a conventional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoelomorpha
Acoelomorpha is a subphylum of very simple and small soft-bodied animals with planula-like features which live in marine or brackish waters. They usually live between grains of sediment, swimming as plankton, or crawling on other organisms, such as algae and corals.Cannon, L. R. G. (1986) ''Turbellaria of the World. A guide to families and genera''. Brisbane, Queensland Museum, 136 p. With the exception of two acoel freshwater species, all known Acoelomorphs are marine. Systematics Etymology The term "acoelomorph" derives from the Ancient Greek words (), the ''alpha privative'', expressing negation or absence, (), meaning "cavity", and (), meaning "form". This refers to the fact that acoelomorphs have a structure lacking a fluid-filled body cavity. Classification The subphylum Acoelomorpha is divided into two classes. There are at least 408 described species, with a majority of these falling within the Crucimusculata infraorder in Acoela. * Acoela comprise small fla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waminoa
''Waminoa'' is a genus of acoels which are epizoic on living corals, using the coral's mucus as a source of food. Unusually, these acoels harbor two genera of endosymbiotic dinoflagellates: ''Symbiodinium'' and '' Amphidinium''; it is not typical for two different genera of dinoflagellates to coexist in a single host. ''Waminoa'''s host coral may also contain dinoflagellates of the genus ''Symbiodinium'' but not ''Amphidinium.'' Only two species belonging to this genus have been discovered ( ''W. litus'' and ''W. brickneri'') and they inhabit coral reefs in the Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ..., Australia, and Indonesia. References Acoelomorphs {{Xenacoelomorpha-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flatworm
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organ (anatomy), organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely parasitic groups: Cestoda, Trematoda and Monogenea; however, since the turbellarians have since been prove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyhelminthes
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no coelom, body cavity), and have no specialized circulatory system, circulatory and respiratory system, respiratory organ (anatomy), organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilateria
The Bilateria or bilaterians are animals with bilateral symmetry as an embryo, i.e. having a left and a right side that are mirror images of each other. This also means they have a head and a tail (anterior-posterior axis) as well as a belly and a back (ventral-dorsal axis). Nearly all are bilaterally symmetrical as adults as well; the most notable exception is the echinoderms, which achieve secondary pentaradial symmetry as adults, but are bilaterally symmetrical during embryonic development. Most animals are bilaterians, excluding sponges, ctenophores, placozoans and cnidarians. For the most part, bilateral embryos are triploblastic, having three germ layers: endoderm, mesoderm, and ectoderm. Except for a few phyla (i.e. flatworms and gnathostomulids), bilaterians have complete digestive tracts with a separate mouth and anus. Some bilaterians lack body cavities ( acoelomates, i.e. Platyhelminthes, Gastrotricha and Gnathostomulida), while others display primary body cavities (de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilaterian
The Bilateria or bilaterians are animals with bilateral symmetry as an embryo, i.e. having a left and a right side that are mirror images of each other. This also means they have a head and a tail (anterior-posterior axis) as well as a belly and a back (ventral-dorsal axis). Nearly all are bilaterally symmetrical as adults as well; the most notable exception is the echinoderms, which achieve secondary pentaradial symmetry as adults, but are bilaterally symmetrical during embryonic development. Most animals are bilaterians, excluding sponges, ctenophores, placozoans and cnidarians. For the most part, bilateral embryos are triploblastic, having three germ layers: endoderm, mesoderm, and ectoderm. Except for a few phyla (i.e. flatworms and gnathostomulids), bilaterians have complete digestive tracts with a separate mouth and anus. Some bilaterians lack body cavities (Acoelomata, acoelomates, i.e. Flatworm, Platyhelminthes, Gastrotricha and Gnathostomulida), while others display pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symsagittifera Roscoffensis
''Symsagittifera roscoffensis'', also called the Roscoff worm, the mint-sauce worm, or the shilly-shally worm, is a marine flatworm belonging to the phylum Xenacoelomorpha. The origin and nature of the green color of this worm stimulated the curiosity of zoologists early on. It is due to the partnership between the animal and a green micro-algae, the species ''Tetraselmis convolutae'', hosted under its epidermis. It is the photosynthetic activity of the micro-algae ''in hospite'' that provides the essential nutrients for the worm. This partnership is called photosymbiosis, from "photo", "light", and symbiosis "who lives with". These photosynthetic marine animals live in colonies (up to several million individuals) on the tidal zone. Biology and ecology Although ''roscoffensis'' means "who comes from Roscoff", this flatworm is not endemic to Roscoff or North Brittany. Its geographical distribution extends over the Atlantic coast of Europe; colonies were observed from Wales to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbellaria
The Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes (flatworms), and include all the sub-groups that are not exclusively parasitic. There are about 4,500 species, which range from to large freshwater forms more than long or terrestrial species like ''Bipalium kewense'' which can reach in length. All the larger forms are flat with ribbon-like or leaf-like shapes, since their lack of respiratory system, respiratory and circulatory system, circulatory systems means that they have to rely on diffusion for internal transport of metabolites. However, many of the smaller forms are round in cross section. Most are predators, and all live in water or in moist terrestrial environments. Most forms reproduce sexual reproduction, sexually and with few exceptions all are hermaphrodites, simultaneous hermaphrodites. The Acoelomorpha and the genus ''Xenoturbella'' were formerly included in the Turbellaria, but are no longer regarded as Platyhelminthes. All th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neochildia Fusca
''Neochildia'' is a monotypic genus of a dark brown acoel belonging to the family Convolutidae. The only species is ''Neochildia fusca''. The nervous system is composed of an anterior compact brain organized as a layer of neural somata surrounding a central neuropil Neuropil (or "neuropile") is any area in the nervous system composed of mostly unmyelinated axons, dendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies. The most prevalent anat ... free of cell bodies. References Acoelomorphs {{Xenacoelomorpha-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenacoelomorpha
Xenacoelomorpha is a small phylum of bilaterian invertebrate animals, consisting of two sister groups: xenoturbellids and acoelomorphs. This new phylum was named in February 2011 and suggested based on morphological synapomorphies (physical appearances shared by the animals in the clade), which was then confirmed by phylogenomic analyses of molecular data (similarities in the DNA of the animals within the clade). Phylogenetics The clade (groupings of organisms based on their most recent shared/common ancestors) Xenacoelomorpha groups the Acoelomorpha and the genus ''Xenoturbella'', due to molecular studies. Initially this phylum was considered to be a member of the deuterostomes, (meaning during development, as an embryo, the anus develops first and then the mouth), but because of recent transcriptome analysis, it was concluded that phylum Xenacoelomorpha is the sister group (two closest relatives in a phylogenetic tree) to the Nephrozoa, which includes both the protostomes (w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinoposthiidae
Actinoposthiidae is a family of acoels.Nilsson, K.S., Wallberg, A., & Jondelius, U. (2011). "New species of Acoela from the Mediterranean, the Red Sea, and the South Pacific." ''Zootaxa'' 2867: 1-31. Taxonomy Genera The following genera are recognised in the family Actinoposthiidae: * ''Actinoposthia'' An der Lan, 1936 * ''Archactinoposthia ''Archactinoposthia'' is a genus of worms belonging to the family Actinoposthiidae Actinoposthiidae is a family of acoels.Nilsson, K.S., Wallberg, A., & Jondelius, U. (2011). "New species of Acoela from the Mediterranean, the Red Sea, and the S ...'' Dörjes, 1968 * '' Atriofronta'' Dörjes, 1968 * '' Childianea'' Faubel & Cameron, 2001 * '' Microposthia'' Faubel, 1974 * '' Paractinoposthia'' Ehlers & Dörjes, 1981 * '' Paraproporus'' Westblad, 1945 * '' Pseudactinoposthia'' Dörjes, 1968 * '' Tetraposthia'' An der Lan, 1936 Species There are 21 species recognised in the family Actinoposthiidae. Notes References External Sites [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isodiametra Pulchra
''Isodiametra'' is a genus of worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wo ...s belonging to the family Isodiametridae. The species of this genus are found in Southern America. Species Species: *'' Isodiametra bajaensis'' *'' Isodiametra colorata'' *'' Isodiametra cuernos'' References {{Taxonbar, from=Q4992813 Acoelomorphs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Symsagittifera Roscoffensis")
