Hydrozoa, also called hydroids are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial sp
The hydroid Tubularia indivisa, fertile
The highly apomorphic Siphonophorae—like this Portuguese man o' war (Physalia physalis)—have long misled hydrozoan researchers.
Limnomedusae like the flower hat jelly (Olindias formosa) were long allied with Anthomedusae and Leptomedusae in the "Hydroida".
Cnidaria is a phylum of animals containing over 11,000 species of aquatic invertebrates found both in freshwater and marine environments, including jellyfish, hydroids, sea anemones, corals and some o
Pacific sea nettles, Chrysaora fuscescens
Oral end of actinodiscus polyp
Cerianthus filiformis (Ceriantharia)
Sea anemones (Actiniaria, part of Hexacorallia)