Ascīdieši vai jūras strūklas 34
Ascīdieši jeb jūras strūklas ir cilindriski jūras bezmugurkaulnieki, kas sastopami galvenokārt tropiskajos un mērenajos ūdeņos. Tās piestiprina pie virsmām ūdenī ar vienu galu, un tām ir divas atveres ūdens izvadīšanai. Lai gan tām trūkst smadzeņu, to centrālā nervu sistēma atgādina mugurkaulniekus. Jūras strūklām ir nervu caurule ar maņu pūslīšiem, vadu, kaklu un astes gangliju. Daži pētījumi liecina, ka jūras strūklu lietošana var palīdzēt novērst novecošanās pazīmes cilvēka smadzenēs.
@svabo.lara Ascidians are filter feeders and characterized by a tough outer "tunic" made of a polysaccharide. 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. Ascidians are found all over the world, usually in shallow water with salinities over 2.5%. While members of the Thaliacea (salps, doliolids and pyrosomes) and Appendicularia (larvaceans) swim freely like plankton, sea squirts are sessile animals after their larval phase: they then remain firmly attached to their substratum, such as rocks and shells. There are 2,300 species of ascidians and three main types: solitary ascidians, social ascidians that form clumped communities by attaching at their bases, and compound ascidians that consist of many small individuals (each individual is called a zooid) forming large colonies. Sea squirts feed by taking in water through a tube, the oral siphon. The water enters the mouth and pharynx, flows through mucus-covered gill slits (also called pharyngeal stigmata) into a water chamber called the atrium, then exits through the atrial siphon.
