Cut off a newt’s tail or a leg, or remove a lens from its eye, and it grows back. However, whether newts can continue to do this throughout their lives, or lose the ability as they get older, has remained a mystery. Now, in an experiment spanning 16 years, Goro Eguchi of the Shokei Educational Institution, Japan, and Panagiotis Tsonis at the University of Dayton, Ohio, have discovered that newts can regenerate missing parts well into old age. With the help of Eguchi's wife, Yukiko Eguchi, they bred and raised captured Japanese fire-bellied newts (Cynops pyrrhogaster) at home. Yukiko’s skill with the newts kept them alive for sixteen years, during which time Tsonis and Eguchi removed lenses from the same animals 18 times. Eguchi estimates that the newts were about 14 years old when he captured them, making them 30 at the time the experiment was completed.
Richard P. Grant