BioConcepts

zoonZoon (ger.)

• An organism scientifically regarded as a complete animal, i.e. one which is the total product of an impregnated ovum, whether constituting a single being as in the higher animals, or a number of distinct beings (zooids) as in the successive asexual generations of aphides or the various ‘persons’ that make up a compound or ‘colonial’ animal. (OED 2011)
  category individual see also zooid

  c. -350 (BC)

  τὸ δὲ ζῷον διὰ τὴν αἴσθησιν πρώτως· καὶ γὰρ τὰμὴ κινούμενα μηδ’ ἀλλάττοντα τόπον, ἔχοντα δ’ αἴσθησιν, ζῷα λέγομεν καὶ οὐ ζῆν μόνον. [but the first characteristic of an animal is sensation; for even those which do not move or change their place, but have sensation, we call living creatures, and do not merely say that they have life.]

  Aristotle (c. 350 BC). De Anima 413b2-4 (transl. W.S. Hett, 1936/57).

  1898

  a zoological individual is constituted either by any such single animal as a mammal or bird, which may properly claim the title of a zoon, or by any such group of animals as the numerous Medusæ that have been developed from the same egg, which are to be severally distinguished as zooids.

  Spencer, H. (1864). The Principles of Biology, vol. 1: 205 (§73).