| In the cnidarians, chaetognaths, and ctenophores, the opaque gut wall was the surface measured. |
| Data from sponges, ctenophores, and cnidarians are providing a glimpse into the some of the earliest events in Hox evolution. |
| Hence ctenophores and cnidarians have traditionally been labelled diploblastic, along with sponges. |
| However, unlike cnidarians, ctenophores possess rows of cilia and a unique, complex sensory organ and lack cnidae and metagenesis. |
| As indicated by its small beak-like mouth, the louvar feeds on small, soft-bodied creatures such as jellyfish and ctenophores. |
| It is therefore largely appreciated that the resemblance between ctenophores and cnidarians is superficial and does not reflect a particularly close evolutionary relationship. |
