Scientists have achieved a remarkable milestone in marine biology by documenting the mating sequence of three leopard sharks—two males and one female—in the wild. This unusual event was captured on camera off the coast of Nouméa, New Caledonia, and represents a significant contribution to the understanding of this endangered species’ reproductive behavior. The findings were published in the Journal of Ethology in March 2025.
The research team, led by Hugo Lassauce, a postdoctoral researcher at the University of the Sunshine Coast (UniSC), has been conducting daily monitoring of sharks in the region. While previous studies on leopard sharks largely focused on captive environments, this observation marks the first time such mating behavior has been recorded in the wild. The study aims to clarify whether mating practices observed in captivity are mirrored in natural settings.
Lassauce, who has spent a year snorkeling with sharks, noticed a female leopard shark resting on the seafloor, attended by two males displaying typical courtship behavior. “I instructed my colleague to move the boat away to minimize disturbance,” Lassauce explained. “I waited on the surface, observing the sharks from above.” After an hour, the male sharks began to swim upwards, with the mating process occurring swiftly—one male took 63 seconds, and the other 47 seconds to complete the act.
Documenting a Rare Encounter
Equipped with two GoPro Hero 5 cameras, Lassauce faced challenges due to battery life limitations. This resulted in two interruptions during the filming: one to switch cameras and another to conserve the second camera’s power. Despite these setbacks, the team successfully captured the entire mating sequence, leading to celebrations among the researchers on the boat.
The sequence began with the three sharks motionless on the ocean floor for nearly an hour. Eventually, the female shark swam with one male holding onto each of her pectoral fins. Within minutes, the first male positioned himself to mate, using his modified pelvic fin, known as a clasper, to transfer sperm. After he completed the mating process, he lay still while the second male took his turn. Following the mating, the female swam away actively, leaving the males momentarily exhausted on the seafloor.
The significance of this observation extends beyond mere curiosity. It indicates that the area may serve as a critical mating habitat for leopard sharks, providing valuable insights for conservation strategies. The research could also inform potential artificial insemination efforts aimed at increasing the population of leopard sharks in their native habitats across Australia and beyond.
Co-author Christine Dudgeon, also from UniSC, highlighted the implications of the findings. “It’s surprising and fascinating that two males were involved sequentially on this occasion,” she noted. “From a genetic diversity perspective, we want to understand how many fathers contribute to the batches of eggs laid each year by females.”
This groundbreaking documentation not only enriches the scientific community’s understanding of leopard shark behavior but also underscores the importance of preserving their natural habitats. The successful capture of such a rare event serves as a reminder of the ongoing need for conservation efforts to protect endangered marine species.
