From RTAW Reefpedia
Organisms within the kingdom Animalia have several characteristics that identify them as such. These characteristics are;
- eukaryotic - multicellular (some exceptions exit),
- digests prey within an internal chamber (some exceptions exit),
- capable of locomotion, and
- respond to their environment.
The kingdom Animalia is divided into two sub-kindoms;
- Eumetazoa - comprises all the major animal groups with the exceptions of sponges. Characteristics include true tissues organised into germ layers and an embryo that goes through a gastrula stage.
- Parazoa - an ancestral subkingdom of animals, with sponges the only surviving phylum. Characteristics include being macroscopic, have differentiated cells and do not have tissues.
- Animalia - Wikipedia