Planula

For the 'Planula hypothesis' of the ancestral animal, see urmetazoan.

A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores, which are not related to cnidarians at all. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva.[1] [2] In a few cnidarian clades, like Aplanulata and the parasitic Myxozoa, the planula larval stage has been lost.[3][4]

  1. ^ Ruppert EE, Fox RS, Barnes RD (2004). "Nemertea". Invertebrate Zoology (7 ed.). Brooks / Cole. pp. 271–274. ISBN 0-03-025982-7.
  2. ^ Maslakova, Svetlana A. (2010-07-19). "Invention of the Pilidium Larva in an Otherwise Perfectly Good Spiralian Phylum Nemertea". Integrative and Comparative Biology. 50 (5): 734–743. doi:10.1093/icb/icq096. ISSN 1540-7063. PMID 21558236. Retrieved 2022-02-03.
  3. ^ Nawrocki, A. M.; Cartwright, P. (2013). "Expression of WNT pathway genes in polyps and medusa-like structures of Ectopleura larynx (Cnidaria: Hydrozoa)". Evolution & Development. 15 (5): 373–384. doi:10.1111/ede.12045. PMID 24074282. S2CID 5337426.
  4. ^ Uspenskaia, A. V.; Raĭkova, E. V. (2001). "Cytological aspects of similarity and difference of Myxozoa and Cnidaria". Tsitologiia. 43 (3): 284–309. PMID 11387759.