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Tunicates
A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the 'seriation of the gill slits'. Some tunicates live as solitary individuals, but others replicate by budding and become colonies, each unit being known as a zooid. They are marine filter feeders with a water-filled, sac-like body structure and two tubular openings, known as siphons, through which they draw in and expel water. During their respiration and feeding, they take in water through the incurrent (or inhalant) siphon and expel the filtered water through the excurrent (or exhalant) siphon. Most adult tunicates are sessile, immobile and perman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplousobranchia
Aplousobranchia is an order of sea squirts in the class Ascidiacea. They are colonial animals, and are distinguished from other sea squirts by the presence of relatively simple pharyngeal baskets. This provides the etymology of their name: in ancient greek, () means "simple". The posterior part of the abdomen contains the heart and gonads, and is typically larger than in other sea squirts. Taxonomy Order Aplousobranchia * Family Clavelinidae Forbes & Hanley 1848 ycnoclavellidae Kott 1990**''Clavelina'' Savigny 1816 [''Bradiclavella'' Zirpolo 1925; ''Chondrostachys'' Macdonald 1858; ''Dendroclavella'' Oka 1927; ''Podoclavella'' Herdman 1890; ''Rhodozona'' Van Name 1902; ''Stereoclavella'' Herdman 1890; ''Synclavella'' Caullery 1900] **''Euclavella'' Kott 1990 **''Nephtheis'' Gould 1856 [''Oxycorynia'' Drasche 1882] **''Pycnoclavella'' Garstang 1891 [''Archiascidia'' Julin 1904] * Family Didemnidae Giard 1872 iplosominae Giard 1872**'' Atriolum'' Kott 1983 **''Clitella'' Kott 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
