Wastewater drains in aquarium systems must be secured separately

Keeping genetically modified fish in aquariums requires special protective measures. In addition to robust containers and aquarium systems with secure closures, water drains must be designed to prevent escape in order to effectively prevent the accidental escape of animals, fish eggs and/or fish larvae (Annex 4 I. a. 3. GenTSV). Sink drains can be secured, for example, by installing a close-meshed grid, sieve or sponge to prevent genetically modified organisms (GMOs) from escaping via the wastewater. The maximum mesh size must be adapted to the size of the fish kept or their eggs and/or larvae. The zebrafish ( Danio rerio ) is a widely used and successful model organism in genetic and developmental biology laboratories. Zebrafish eggs have an average diameter of 0.7 mm. The fish larvae are approximately 3.5 to 4.5 mm long and more than 0.5 mm wide (source: https://zfin.org/zf_info/zfbook/stages/ ). In the case of zebrafish, all sink drains and drains must be protected with a filter net with a mesh size of less than 0.5 mm. Since the eggs or larvae of genetically modified fish can adhere to the nets, sieves, or sponges used in the drains, they must be inactivated by autoclaving when changing or disposing of the fish. Also, remember to list the safety measures taken in the operating instructions and to include them in the training of the personnel responsible for maintenance.