Animal testing on invertebrates

Most animal testing involves invertebrates, especially Drosophila melanogaster, a fruit fly, and Caenorhabditis elegans, a nematode.

These animals offer scientists many advantages over vertebrates, including their short life cycle, simple anatomy and the ease with which large numbers of individuals may be studied.

[5] The simple nervous system of this nematode allows the effects of genetics on the development of nerves to be studied in detail.

[6] However, the lack of an adaptive immune system and the simplicity of its organs prevent C. elegans from being used in medical research such as vaccine development.

Molecular biology is relatively simple in these organisms and a huge variety of mutant and genetically modified flies have been developed.