This film shows some of the aspects of zebrafish production and maintenance. Zebrafish embryos, unlike mouse embryos, develop outside the mother’s body and are transparent throughout the first few days of life. This provides unparallelled opportunities for researchers to scrutinise the fine details of embryonic vertebrate development without first having to resort to invasive procedures or killing the mother. This advantage is enhanced by the fact zebrafish can produce 200-300 fertilised eggs every week. High Definition clips from this film are available on request to email@example.com.