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 .

（Acoela） 生活在海水中，小型涡虫，体长1mm-12mm，通常约2mm，体长圆形，口位于近中央的腹中线上，有的具一简单的咽，无消化管，有一团来源于内胚层的 营养细胞 进行吞噬和消化。无原肾管，神经系统很不发达（包括脑及多条神经索并连成网状），有的为 ...

2012年9月29日 · Acoels are acoelomate, the space between gut and body wall being filled with parenchymal cells that occasionally contain chordoid vacuoles and the insunk bodies of epidermal and gland cells. The name ‘acoel’ comes from their lack of a …

1 天前 · eLife Assessment. Xenacoelomorpha is an enigmatic phylum, displaying various presumably simple or ancestral bilaterian features. This valuable study characterises the reproductive life history of Hofstenia miamia, a member of class Acoela in this phylum. The authors describe the morphology and development of the reproductive system, its changes upon degrowth and regeneration, and the animals ...

2011年12月8日 · The Acoela is a small phylum which comprises approximately 400 species of small, mostly marine ‘worms’ that are completely ciliated. The acoels have an unquestioned monophyly and a well-documented phylogenetic position as one of the ‘basal’ metazoan groups.

无腔动物亚门（学名：Acoelomorpha）是异无腔动物门下的一个亚门。 它们拥有浮浪幼虫样动物的特征，以往被认为是属于后口动物，但有学者将它们成立为一个独立于后口动物的门。 经过miRNA分析，若按照亲缘分支分类法应分类于异无腔动物门之下。 无腔动物差不多完全是水生的，栖息在沉积物中，游泳像 浮游生物 或在藻类上爬行。 它们有平衡囊，可以帮助它们平衡。 柔软的身体令学者很难将它们分类。 无腔动物非常细小，只长2毫米以下，没有消化道。 消化是由 …

2009年4月14日 · What are acoels? Acoels are small (less than 15 mm) soft-bodied, unsegmented worms. They live only in marine habitats and are found in all the world's oceans. They constitute their own clade ‘Acoela’, in which there are approximately 370 species. The name ‘acoel’ refers to their lack of a gut cavity as well as a coelomic cavity.

2008年9月17日 · A through gut could have been present in the last common ancestor of all bilaterians and the anus could have been lost independently in both Acoela and Nemertodermatida lineages.

Acoela are found worldwide in mostly shallow waters in all oceans from tropical to polar regions. Habitat. Acoela live in marine or brackish water. Some species drift or swim in the open sea, or live unobtrusively among sand grains on sea bottoms in shallow coastal waters. Some even live in cold brine channels within Antarctic ice floes. Behavior

The Acoela or acoels are a class of small and simple invertebrates in the phylum Xenacoelomorpha that resemble flatworms. Historically they were treated as an order of turbellarian flatworms, but molecular phylogeny studies revealed them to be basal bilaterians.