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Tiny reef speedster challenges tuna in the ocean sprint

Tiny coral reef wrasses can swim as fast as some of the swiftest fish in the ocean – but using only half as much energy to do so.

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By flapping their fins in a figure-eight pattern, bluelined wrasses can travel at high speeds while using 40 per cent less energy than tunas of the same size.

“For a long time, people thought the best high-speed swimmers were the fishes cruising in open waters, like mackerel and tunas,” says Dr Chris Fulton from the ARC Centre of Excellence for Coral Reef Studies and The Australian National University.

“Our study shows that these coral reef wrasses, by virtue of their unique wing-like fins, can maintain very similar speeds at a dramatically lower energetic cost,” he says.

The researchers’ discovery could help revolutionise robot submarine technology by reducing how much energy is needed to propel objects underwater.

Current Autonomous Underwater Vehicles (AUVs) use propellers or jets at the back. “By replacing these with fins at the front to mimic how the bluelined wrasses flap their fins, we could propel robots with less power, saving on batteries and increasing their range,” Dr Fulton says.

Dr Fulton explains that fish like tunas and mackerels move their bodies and tails to propel themselves through the water. While this method enables them to swim fast, it can come at a high energetic cost.

“Another way fish swim is to use their pectoral fins, those at the front of their body, to produce thrust,” says Dr Fulton. “Fishes that do...

The full text of this article can be purchased from Informit.