Taiwanese scientists have created more two-headed genetically modified Zebra danios, according to the Taipei Times.
The research group at the Institute of Biological Chemistry at Taiwan's Academia Sinica found a single two-headed danio in a recent brood of transgenic fish and found that the individual also had two hearts.
The workers could find no record of similar fishes and have reported on their findings in the journal Science this week.
The team are using the GM techniques to investigate the mechanisms that cause conjoined twins to develop and have injected a further series of genes into 750 embryos over the past month. They now have eight two-headed fish which all differ slightly in the way they are joined.