A half-male, half-female butterfly hatched at London’s Natural History Museum causing quite the buzz.
The butterfly is a great mormon from Asia, and hatched at the museum’s butterfly exhibit, Sensational Butterflies. According to the museum, the butterfly is a pure bilateral gynandromorph. This means that the butterfly is exactly half-male and half-female. One side of the butterfly features paler coloring, while darker coloring is evident on the opposite side.
BBC reported that the coloring isn’t the only thing affected. The butterfly’s body is also split in two including its sexual organs and the butterfly’s antennaes, which are different lengths.
Gynandromorph is caused by the failure of the butterfly’s sex chromosomes to separate during fertilization, leaving the insect with both male and female cells. Another way gynandromorph can occur is when an egg with two sex chromosomes gets fertilized by two sperm.
The museum reveals that gynandromorph happens very rarely across a range of insect species.
“Pure bilateral gynandromorphs are incredibly rare, and I have only ever come across 3 in my whole career of 30 years. So you can understand why I was bouncing off of the walls when I learned that a stunning half-male, half-female bilateral gynandromorph had emerged in the puparium at this year’s Sensational Butterflies exhibition. Many permanent butterfly exhibitions will go through their entire existence without ever seeing one of these rarities,” said Manager of Sensational Butterflies, Luke Brown.
Reportedly, when the butterfly dies, it will be added to the Museum’s world class Lepidoptera collection.