Noun
A comprehensive group equivalent to the true Coelenterata, i. e., exclusive of the sponges. They are so named from presence of stinging cells (cnidae) in the tissues. See Coelenterata.
Source: Webster's dictionaryIn 1881, it was proposed that Ctenophora and Bilateria were more closely related to each other, since they shared features that Cnidaria lack, for example muscles in the middle layer ( mesoglea in Ctenophora, mesoderm in Bilateria). Source: Internet
However more recent analyses indicate that these similarities are rather vague, and the current view, based on molecular phylogenetics, is that Cnidaria and Bilateria are more closely related to each other than either is to Ctenophora. Source: Internet
The polyps resemble the closely related Cnidaria anthozoan ( sea anemones and corals ) polyps. Source: Internet
Asexual reproduction makes the daughter Cnidaria clone the adult. Source: Internet
Main cell layers Cnidaria are diploblastic animals; in other words, they have two main cell layers, while more complex animals are triploblasts having three main layers. Source: Internet