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They cling to whales for a 10,000-kilometre joy ride along Australia's east coast, scoring free meals along the way. Remoras may just be the animal kingdom's ultimate freeloader, but researchers say there is a lot to learn about the love-hate relationship these suckerfish have with humpbacks. "They're hitchhikers in the ocean and it's a very bizarre lifestyle too," Griffith University's Olaf Meynecke said. Dr Meynecke has been slapping suction-cup cameras on the back of whales to observe their behaviour off Queensland's Gold Coast over the annual migration season. But after the cameras were being consistently photobombed by these whale-sucking remoras, Dr Meynecke decided to look a littler closer. 'Not big fans' Remoras hatch in the open ocean, using a suction cap on their heads to attach to larger animals over their seven-year life cycle. Dr Meynecke said they had a commensal relationship with hosts such as whales, eating sea lice, other parasites and even dead skin. "They will just switch between whales, they'll move around, that's where they mate and that's where they find their food," he said. But that does not mean they are not irritating. "It's a coexistence but we've seen [whales] eyeing them, literally looking at them, and we've seen them actively breaching when they have a lot of these remoras," he said. "It suggests generally they're not big fans." Dr Meynecke said his team had observed whales shredding large amounts of skin — a potential sign of stress — attracting large numbers of remoras. "The whales are supporting … a completely different species," he said. "With that species probably come other species that attach themselves to the remoras — there may be remora hitchhikers too." A lot of unknowns PhD student Sarah McCulloch has been studying whales for almost 10 years. "They don't care that you want to see feeding behaviour, or this behaviour. They're wild animals, they do what they want to do." She said capturing vision of remora behaviour by coincidence opened up new lines of research that could benefit future conservation efforts. "We think humpback whales are doing really well, particularly in Australian waters. "But we don't know going into the future if that's going to continue — there's a lot we don't know." Dr Meynecke said learning more about remoras would give insights into the health of the whale population they depended on. "[But] is every remora going down to Antartica, probably not, how many times do they switch hosts, how far north are they going? "There's a number of unknowns."
