
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and some species of Ctenophores, which are not closely related to cnidarians. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva. In a few cnidarian clades, like Aplanulata and the parasitic Myxozoa, the planula larval stage has been lost.
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and some species of Ctenophores, which are not closely related to cnidarians. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva. In a few cnidarian clades, like Aplanulata and the parasitic Myxozoa, the planula larval stage has been lost.
==Development== thumb|236x236px|Planula stage of Clytia hemisphaerica The planula forms either from the fertilized egg of a medusa, as is the case in scyphozoans and some hydrozoans, or from a polyp, as in the case of anthozoans.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).