Class
Hydrozoa
Hydrozoa
71 species in this taxon
class of cnidarians Hydrozoa (Hydrozoa) is a class of organisms united by key anatomical and physiological traits. It contains 5 orders with 71 known species. This includes the order groups Anthoathecata, Leptothecata, Limnomedusae, Siphonophorae, and Trachymedusae. Among its members, 2 species are currently classified as threatened (Critically Endangered, Endangered, or Vulnerable). It belongs to Cnidarians (Cnidaria).
