The scientists say the Paris japonica has a genetic code 50 times longer than that of a human being and edges out its nearest competitor, the marbled lungfish.
A genome is the full complement of an organism's DNA, complex molecules that direct the formation and function of all living organisms.
Scientist Ilia Leitch today said the code for Paris japonica is so long that if it were stretched out it would be taller than Big Ben.
Outside researchers caution that micro-organisms known as amoebas might have longer codes still, but say the find illustrates the staggering diversity of genome sizes.
Published 08 October 2010, 10:42 IST