Summary The worldwide growth of aquaculture has been accompanied by a rapid increase in therapeutic and prophylactic usage of antimicrobials including those important in human therapeutics. Approximately 80% of antimicrobials used in aquaculture enter the environment with their activity intact where they select for bacteria whose resistance arises from mutations or more importantly, from mobile genetic elements containing mult...

Repeated non‐invasive sampling of zebrafish Danio rerio sperm was conducted, sperm counts were obtained and a method for measurement of DNA damage in sperm was developed and validated (single‐cell gel electrophoresis, comet, assay). DNA damage in sperm increased with concentration of hydrogen peroxide ( H 2 O 2 , 0–200 µM ), and in vitro exposure of sperm to 200 µM H 2 O 2 produced 88·7 ± 3·9% tail DNA compared to unexposed co...