21 December 2006
A little Komodo lay down its sweet head
The Komodo Dragon is one of the largest reptiles on the planet. A huge monitor lizard found on a handful of islands in Indonesia its razor-sharp, serrated teeth are so teeming with bacteria that one bite can prove fatal
However, According to today’s Guardian, scientists have discovered that the Komodo dragon can reproduce by parthenogenesis. Dragons at London and Chester zoos have laid eggs without having mated. Four eggs at London zoo have already hatched while anothereight at Chester zoo are due to hatch within weeks.
Although it has been seen in other species of lizards it is the first time that parthenogenesis has been documented in Komodo dragons. "We've ruled out any potential father," said Richard Gibson at the Zoological Society of London, who has been monitoring the progress of the fatherless baby lizards at London zoo. Not that a male could get in with a female without someone noticing, but just to make sure that everyone was completely convinced we DNA fingerprinted everybody and everything." Kevin Buley, Chester zoo's curator of lower vertebrates and invertebrates, added: "We will be on the lookout for shepherds, wise men and an unusually bright star in the sky over Chester zoo."
A captive-bred female called Sungai laid a clutch of 22 eggs at London zoo in 2005; four babies hatched in March this year. Sungai last had contact with a male called Kimaan two and a half years previously. But genetic tests on the offspring ruled Kimaan and all the other males at London zoo out as potential fathers. Now the focus has turned to the eggs of Flora, a female at Chester zoo. Flora has never had any contact with a male. She was brought to the zoo aged around one year and females do not reach sexual maturity until four or five.
Flora laid a clutch of 25 in May of which eight eggs still survive. Similar genetic detective work has ruled out the influence of any other male. The tests suggest that instead of having two different sets of chromosomes from a mother and father, the offspring have two identical sets of chromosomes, both from their mother. "It's not very clear exactly what happens and we don't know whether it has occurred in the wild. But the fact that it has happened twice in such a short space of time with two unrelated females suggests that it is more common than we think," said Mr Gibson.
Parthenogenesis is common in invertebrates such as wasps, aphids and water fleas but it is rarely found in backboned animals. A handful of reptiles and fish can do it and it has also been found in turkeys.
Komodo Dragon parthenogenesis