The classification of
Aureilia aurita can be understood when a basic characteristics of
each level of classification is known.
Domain Eukarya is simply represented by organisms who have similar
characteristics such as a cell nucleus, a cytoskeleton, mitosis, and
multiple, linear DNA. All animals are included in this domain.
Kingdom Animalia consists of multicellular, non-photosynthetic
organisms with no cell walls.
Jellyfish and sea anemones are both part of the phylum Cnidaria.
They are multicellular, diploblastic, radial symmetric organisms with
Class Scyphozoa consists of cup animals and jellyfish.
They are characterized by having a polyp stage called scyphistoma and
contracting/relaxing muscles along base of their bell-shaped body.
Order Semaestomeae, to which Aurelia aurita grouped, is
characterized by four oral arms and a gastrovascular system of
unbranched pouches and no ring canal.
Family Ulmaridae is simply a family of jellyfish.
basically consists of a variety of moon jellyfish, most well-known,
of course, is the species Aurelia aurita.
The reasons for the
classification of Aurelia aurita is very understandable when the
characteristics of each group, stated above, are taken into
The figure above shows where Aurelia aurita are placed in the
metazoan phylogenic tree. Metazoans are simply multicellular
organisms with differentiable tissues and organs usually including a
nervous system and digestive cavity.
Recall from above that Aurelia aurita is a
scyphozoan belonging to the phylum Cnidaria. The phylum Cnidaria
is very closely related to the phylum Ctenophora which consists of comb
jellies. Both of these organisms are placed seperately from the
phylum Porifera (sponges) becasue the are eumetazoans. This means
they have a digestive tract while sponges do not. Moon Jellies do
not have bilateral symmetry and are thus not grouped with protostomes or
deuterostomes. Ultimately, sponges, comb jellies, moon jellies,
and protostomes and deuterostomes all relate back to a common protist