A swell shark egg has mysteriously hatched despite no male sharks being present in the tank.

The pup, nicknamed Yoko, hatched on 3 January 2025 at the Shreveport Aquarium in Louisiana with help from the aquarium team.



The egg was discovered eight months ago but the Shreveport Aquarium believe it may have gone undetected for an additional two months.

The team said the two female sharks present in the tank had not been in contact with a male for more than three years, making the birth all the more mysterious.

The cause of the birth has yet to be determined but it is believed to be the result of parthenogenesis, an asexual reproduction in which a female can produce an embryo without fertilizing an egg with sperm, or delayed fertilization.

DNA testing in the coming months will confirm whether Yoko's birth was due to parthenogenesis or stored sperm from prior mating.

Yoko is currently thriving in quarantine under the care of aquarists and will soon join the aquarium's exhibits.

Greg Barrick, Curator of Live Animals at Shreveport Aquarium, said: "This situation is incredible and shows the resilience of this species."

"It really proves that life finds a way."