By CHARLOTTE GRAHAM-McLAY
WELLINGTON, New Zealand (AP) — There are easier ways to cross an ocean, but few are as slick or stylish as the remora’s whale-surfing joyride.
Scientists tracking humpbacks off the coast of Australia have captured rare footage that shows clutches of the freeloading fish peeling away from their host in what looks like a high-speed game of chicken, just moments before the whale breaches.
As the humpback plunges back below the surface the remoras, also known as sucker fish, return to the whale, sticking their landings with the timing and precision of Olympic gymnasts. It’s elegant work for a hitchhiking fish that lives upside-down and survives on dead skin flakes.
Remora australis spend their lives aboard whales or other large marine mammals, which they ride like giant cruise ships, breeding and feeding their way across stretches of ocean. The species has an adhesive plate on its head that helps to create a kind of vacuum seal, allowing the fish to grab a whale and hang on for the ride.
On whale cams, clingy fish steal the show
The marine scientist who recorded the accidental close-ups of the remoras’ high-speed whale surfing had placed suction-cup cameras on humpbacks during their annual migration from Antarctica to the waters off Australia’s Queensland state. Olaf Meynecke planned to study whale behavior, but his video feeds regularly filled with dozens of photobombing remoras, which rode in groups of up to 50 as they clung to the same spots where his cameras were attached.
“Whenever the whale was breaching and doing in particular fast movements it appears that the sucker fish were responding very quickly to the movements,” said Meynecke, from the Whales and Climate Research Program at Griffith University. “They knew exactly when to let go of the body of the whale before it was breaching the surface of the water and then returned to the same spot only seconds later.”
A hitchhiker with good instincts
Remoras are harmless to the 40-metric ton (44-U.S. ton) giants of the ocean, feeding on the whales’ dead skin and sea lice in a mutually beneficial arrangement — or at least that’s what scientists say. Meynecke said his footage suggested the whales found their hangers-on annoying.
“We’ve had individuals with high numbers of these remoras and they were continually breaching and there were no other whales that they were communicating with,” he said. “It appeared that they’re trying to just get rid of some of these remoras and they were checking whether they had less after they breached.”
The journey’s end remains a mystery
Australia’s so-called humpback highway is a migratory corridor traversed by 40,000 of the mammals, bringing them close to the country’s eastern coastlines for months each year as they move from icy Antarctic waters to the balmy seas off the coast of Queensland and back. How long much of the 6,000-mile journey is undertaken by the freeloading fish, which only live for about two years, is still a puzzle, Meynecke said.
“I suspect that the majority would probably leave at some point, maybe in temperate waters, but then where do they go?” he said. “Do they find other species that they can then use as a host and wait until the humpback whales have come back?”
In the absence of whales, sucker fish avoid predators by seeking other large creatures to latch onto, including manta rays, dolphins and unlucky scuba divers.
“Much to the annoyance of the divers, of course,” Meynecke said. “They’re not easy to get rid of.”
Source: Berkshire mont
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