Five arrested over genetically modified Oryzias cultivation in Japan


Four people have been referred to prosecutors and five have been arrested following allegations of illegal Japanese ricefish, Oryzias latipes, cultivation. The arrests came after police received a tip in 2022 that genetically modified fish had been sold at an exhibition in Tokyo.

The fish, believed to have been originally taken more than 10 years ago from a lab at the Toyo Institute of Technology, were strains that have been genetically modified (GM) to glow red. Such ‘Glofish’ are popular in America where several different fluorescing colours of the fish exist. 

In all, 1400 genetically modified fish were seized from multiple locations. Prior to the seizures, some of the fish are known to have been released into the wild, though authorities believe at this time that no ecological risk is posed by them. It was later confirmed that two fish had been sold for ¥100,000 (approx. £617) 

The arrests are the first under Japan’s Cartagena law, a law regulating genetically modified living organisms that came into force in 2004. The law requires that government authorisation is obtained by any persons wishing to keep and/or sell GM living organisms, after proving that their escape or release would not negatively affect biodiversity. 

All of the nine suspects, including a former student of the university, have admitted to the charges. Among them is a 60-year-old office worker, Nsaoji Aoki, who is suspected of transporting and breeding the fish without authorisation. Toshikazu Furukawa, another suspect in the case, is alleged to have disposed of some of the fish in an irrigation channel in Chiba Prefecture. 

An investigation revealed that a 35-year-old former student who belonged to the lab working with the fish allegedly handed over some GM eggs to the mother of a fellow student, resulting in their dispersal.