CANBERRA, Dec. 6 (Xinhua) -- The sex of great white sharks is determined by genetics rather than environmental factors, Australian research has found.
In a study published on Wednesday, a team from national science agency the Commonwealth Scientific and Industrial Research Organization (CSIRO) discovered that, like humans, great white sharks have X and Y sex chromosomes.
The discovery led to the team developing a new polymerase chain reaction (PCR) test that can be used in labs to identify the sex of a white shark from a tissue biopsy.
Floriaan Devloo-Delva, a postdoctoral research fellow at the CSIRO's Australian National Fish Collection, said in a media release that the team used a statistical method to search DNA data for sex chromosomes in a large sample of great white sharks.
"We discovered that sex determination in the White Shark is driven by genetics, not by temperature like in crocodiles or turtles," he said.
"Our study showed that the White Shark has X and Y sex chromosomes. Males are XY and females are XX.
"This knowledge reveals more about the biology and population ecology of White Sharks, and will help management agencies better understand the species."
Despite being an apex predator, the great white shark is listed as vulnerable by the International Union for Conservation of Nature (IUCN), with the species' population in decline globally.
Devloo-Delva said that the new PCR test would be particularly helpful for identifying the sex of juvenile sharks that have not yet developed external sex organs, allowing for greater monitoring and conservation efforts. ■
