The two female dragon lizards switch from antagonist to amicable when one of them develops a masculine trait.
The Sea Life Aquarium in Melbourne once kept a male Boyd lizard and two females of the same species. Shortly after the male’s death, staff noticed unusual changes in one of the female dragon lizards. After careful observation, they concluded that it was a sex change, which had never been noticed before in adult reptiles.
Boyd lizards are small, arboreal lizards found in the rainforest of northern Queensland. Before changing her sex, the female dragon lizard once mated with males and laid eggs, helping aquarium staff confirm her sex. However, he has now stopped spawning and developing many masculine traits, including the testes.
Staff at Tom Fair said that the two female dragon lizards have had strong competition over the years, although one was clearly dominant. “The first thing that caught our attention about the change was that the two animals started to get along, on the same branches rather than at the ends of the tank, looking at each other,” Fair said.
This could be the result of the male dying or moving to a new cage at the same time. However, aquarium staff observed that the dominant dragon lizard continued to grow, even though it had previously reached a common female weight of 100g. In addition, its ridge becomes thicker, a noticeable difference between male and female in this species.
The process went very slowly, but the dragon lizard now weighs 160g, a common weight for males. “We did an ultrasound test to identify the animal’s reproductive organs. Surprisingly, we found that it no longer had ovarian tissue, but rather mature testes. I think this is the first time that a transgender occurs in Boyd’s dragon lizard, ”Fair said.
The aquarium did not have the resources to test the dragon lizard’s genetics to see if it had an abnormal chromosome, or it was an evolutionary response when a female did not have a male nearby. Fair said the aquarium was discussing the tests with scientists. Meanwhile, the remaining female still regularly lays eggs and aquarium staff are checking to see if any eggs have been fertilized, as well as mating behavior between two animals.