Hypnotized and collected sperm: scientists are using an unusual method to save leopard sharks.

Scientists are utilizing an unusual method to collect sperm from male leopard sharks. This crucial step for their conservation will enable researchers to conduct the first artificial insemination of sharks in Australia, reports IFLScience.

To handle these sharks safely, marine researchers employ a technique known as "thanatosis" to hypnotize the animals. The sharks enter a temporary trance-like state.

As a result, they become more docile, allowing scientists to collect the necessary samples. This process is entirely safe, and once the sharks are released, they quickly return to their normal behavior.

Thanatosis, or the reflexive or behavioral reaction of certain animals when their bodies mimic death, is not exclusive to sharks. Other species, particularly rays and birds, exhibit similar responses.

Although the exact reason for this phenomenon remains unclear, it may play a specific role in mating for some species or serve as a protective mechanism for others.

In the case of sharks, inducing this state allows researchers to gather vital samples.

"This meant that our team of five could collect sperm and blood samples from male sharks underwater in the wild using a syringe," explained Dr. Christine Dajon, a researcher specializing in leopard sharks.

"I never thought I would be so close to sharks underwater," she joked.

The researchers' actions are linked to the status of Indo-Pacific leopard sharks (Stegostoma tigrinum), also known as zebra sharks due to the striped pattern observed in young individuals. Currently, these animals are listed as endangered on the Red List.

Therefore, Dajon and her colleagues from around the globe are working to assist the species by artificially inseminating female leopard sharks in the aquariums of Sea World Gold Coast, SEA LIFE Sydney Aquarium, and Resorts World Sentosa in Singapore.

"We hope that this marine breeding method will be a game-changer for international projects aimed at reproducing the Stegostoma species worldwide, particularly in regions like Indonesia, where it is at risk of extinction," the researcher added.

Additionally, the team is closely monitoring the DNA of the offspring to study parthenogenesis—a form of asexual reproduction documented in this shark species.

"Once these egg capsules are laid and identified as fertile, they will be sent to our partners in the Raja Ampat Islands until they hatch into young sharks that hopefully will help replenish the stocks of these protected waters," Dajon added.

Aside from artificial insemination, researchers are also tagging sharks with safe devices to track their movements.

"Now we can monitor the movements of these sharks using a network of marine acoustic receivers to further inform conservation efforts as part of this ambitious population reproduction project," Dajon concluded.