Wellington, New Zealand
AP
—
There are easier ways to cross the ocean, but few are as smooth and stylish as whale surfing for rebar sharks.
Scientists tracking a humpback whale off the coast of Australia captured rare footage of the whale peeling a school of freeloading fish from its host in what appears to be a high-speed chicken race just before it pounces.
As the humpback returns to the surface, the remora, also known as a sucker fish, returns to the whale and continues landing with the timing and precision of an Olympic gymnast. It’s an elegant job for a hitchhiking fish that survives by lying upside down and eating flakes of dead skin.
Red sharks spend their lives riding whales and other large marine mammals, riding them like giant cruise ships to breed, feed, and travel across vast oceans. This species has a sticky plate on its head that helps form a kind of vacuum seal, allowing the fish to hang onto the whale to grab onto it and continue riding.
The marine scientist who happened to capture this close-up shot of a remora shark’s high-speed surfing was placing a suction-cup camera on humpback whales during their annual migration from Antarctica to the coast of Queensland, Australia.
Olaf Meinecke had planned to study whale behavior, but his video feed regularly showed dozens of photobomb remora sharks, clusters of up to 50 clinging to the same spot where his camera was mounted.
“It appears that whenever the whale was breaching and making particularly fast movements, the sucker fish were reacting very quickly to that movement,” said Meinecke, from the Whale and Climate Research Program at Griffith University.
“They knew exactly when to let go of the whale before it broke the surface and returned to the same spot just seconds later.”
The remora shark feeds on the whale’s dead skin and sea worms in a harmless and mutually beneficial arrangement for the 40 metric ton (44 US ton) sea giant – at least that’s what scientists say. Meinecke said the footage suggests the whales find the hangers-on a nuisance.
“We observed individuals with large numbers of these rebar sharks, but they were continuously invading and there were no other whales with which they were communicating,” he said. “It appears they were trying to remove some of the rebar sharks and see if their numbers had decreased after the invasion.”
The end of the journey remains a mystery
Australia’s so-called humpback highway is a migratory corridor traversed by 40,000 mammals, which spend several months each year close to Australia’s eastern coastline as they make their way from the icy Southern Ocean to the balmy waters off the coast of Queensland and back.
Meinecke said it’s still a mystery how much of a 10,000-kilometre journey these freeloader fish, which live only about two years, cover.
“I think the majority will probably leave at some point, maybe in temperate waters, but then where do they go?” he said. “Will they find other species to use as hosts and wait until the humpbacks return?”
In the absence of whales, sucker fish avoid predators by seeking out other large creatures to prey on, such as manta rays, dolphins, and unlucky scuba divers.
“Of course, it’s a huge nuisance for divers,” Meinecke said. “It’s not easy to get rid of them.”
