While doing studies with genetic engineering to explore muscular dystrophy and possible cures, a research team from Academia Sinica, in Taiwan, have developed a two-headed zebra fish.

The fish has two heads and two hearts. Huang Chang-jen, an associate research fellow involved said: "You can say they are actually a big zebra fish and a small one sharing a body."

The scientists were adding the gene responsible for causing muscle death into 200 fish embryos, the next day they found the two-headed fish had developed.