Rare Dual Sex Butterfly Hatched At The Natural History Museum

By Londonist Last edited 88 months ago
Rare Dual Sex Butterfly Hatched At The Natural History Museum

A rare half-male half-female butterfly has been born at the Natural History Museum’s ‘Sensational Butterflies’ exhibition.

Known as a gynandromorph, the Great Mormon butterfly has one side of its body which is female and one side which is completely male; from the wing colour (the more colourful right side is female) and sexual organs, even down to the length of the antennae. You can see a line down the middle of the butterfly’s body separating the two.

Gynandromorphy is caused by the butterfly’s sex chromosomes failing to separate in the fertilised egg. It can occur in several species, including crabs and spiders but the condition is extremely rare. Luke Brown the butterfly house manager said “I have only ever come across two in my whole career. So you can understand why I was bouncing off of the walls when I learned that ..[it] had emerged in the puparium.”

At three and a half weeks old the butterfly has already reached middle age, but if you want to try and catch a glimpse of a biological marvel then the exhibition is at the Natural History Museum until 11 September.

When the Great Mormon butterfly dies it will be added to the Natural History Museum’s collection to be studied.

By Kate Lamble

Image courtesy of Natural History Museum

Last Updated 13 July 2011