Even the biggest fish in the sea have their secrets—but now, scientists have captured rare footage of whale shark courtship behaviors, offering new insights into the elusive sex lives of these giants.
The video was captured in May 2024. Researchers entered the water after getting tipped off by a spotter plane that sighted a female whale shark in 131-feet-deep (40 meters) waters off Western Australia’s Ningaloo Reef. Shortly after sampling that shark, a male whale shark came along, and the research team took video footage of the two sharks’ interactions. The team’s research was published this month in Frontiers in Marine Science.
Whale sharks (Rhincodon typus) are elasmobranchs—the group of cartilaginous fish that includes sharks, rays, skates, and sawfish. Whale sharks also happen to be the largest fish in the world, typically measuring about 30 feet (9 m) long. According to the American Museum of Natural History, one of the biggest-ever whale sharks was nearly 61.67 feet (18.8 m) long. The largest known whale shark egg, found in 1953, was nearly a foot (0.3 m) long.
The animal’s mating behaviors remains fairly enigmatic—courtship has only been observed off the Saint Helena Islands and at Ningaloo Reef.
At Ningaloo—the sight of the recently described behavior—male whale sharks outnumber females three to one, based on data collected from over 1,000 sharks in the area in the last decade.
Sharks off Saint Helena have been observed positioning themselves in a belly-to-belly formation, though the recent encounter didn’t get that far. In the May 2024 event, the team observed the male shark follow and lunge multiple times at the female.
“The male shark increased its swimming speed and lunged again at the caudal fin of the female, this time making contact and briefly biting the tail,” the team reported. “The female responded by rapidly pivoting with pectoral fins pointing downwards to face the male.”
But the recent pair wasn’t made in heaven. The female turned away from the male and “rapidly descended to depth.” The team stated that the behaviors they observed “did not appear to result in successful mating,” though it’s possible the two sharks coupled in deep water. The team concluded that the female they observed may not have been sexually mature based on its size.
Whale sharks are an endangered species. According to AMNH, the species’ population may have declined by 50% in the last 75 years. The whales are illegally hunted for their meat, are caught as bycatch, and their habitats are harmed by oil spills, plastic pollution, and human shipping and tourist activity.
The recent video shows that in spite of many threats, the giant fish is nevertheless persisting—though perhaps not for this particular couple. Love is in the air—er, water—for whale sharks, and scientists managed to capture it on camera.