International study reveals the secret surfing life of remora hitchhiking on blue whales


A Remora credit associated with the skin of a blue whale: Stanford University and the Cascadia Research Collective. Image collected under NMFS permit # 16111.

Sticking to the bodies of sharks and other large sea creatures is a well-known feature of Remora fishes (Ikenadi) and has super-powered suction disks on their heads. But a new study has now fully documented “suckerfish” in hitchhiking action below the ocean’s surface, showing a more sophisticated skill that fish use to navigate the intense hydrodynamics that 100- Come up with an attempt to ride on Ft. Blue whale (Balaenoptera musculus).


In a study published on 28 October Journal of Experimental BiologyPalos Verde and an international team of researchers studying the unique liquid environment of blue whales migrating off the coast of San Diego, made the first continuous recording of Remora’s behavior on a host organism using advanced biosing tags for video recording Capture is reported. Capabilities.

The study shows the secrets behind the success of the Remora fish in woolly whales more than 30 times their size to safely cross the ocean – they are the most flow-optimal on the whale’s body to stick to the whale’s body Select areas, such as those behind whales to fly. Where the drag resistance for fish is reduced by 84%. The team’s findings also suggest that Remora can roam freely to feed and socialize on her ride, as her whale host hits previously used specialized low-drag traveling alleys with more unknown surfing and skimming behaviors. , Hitting speeds of more than 5 meters per second. Away from the surface of the whale’s body.

Researchers say the study represents a dynamic analysis of the whale’s highest-resolution whole-body fluid, from which it can potentially be used to better understand species behavior, energy use, and overall ecological health. Can be done for Improving tagging and tracking of whales and other migratory animals in future studies.

“Whales are like their own floating islands, basically like their own small ecosystems. … It is very exciting to have a look at the atmosphere of the flow of blue whales within one millimeter resolution through this study, “Said Brooke Flemung, assistant professor of biology. And the corresponding author of the study at the New Jersey Institute of Technology. “Through lucky coincidence, our recordings captured how Remora interacts in this environment and are able to use the dynamics of the different flows of these whales to their advantage. This is incredible because We don’t really know anything about how Remora behaves on her hosts. Wild for any long time. ”

Until now, scientists have largely relied on evidence from still images and anecdotes, studying the symbiotic relationship between Remorse and their hosts in their natural oceans, about their behavior as a mystery beneath the surface I know a lot.

International study reveals the secret surfing life of remora hitchhiking on blue whales

Remora feeding and skimming along the whale’s body. Credit: Stanford University and Cascadia Research Collective. Image collected under NMFS permit # 16111.

In their recent investigation, the researchers employed multi-sensor biologging tags with dual cameras, which they attached to the whale via four 2-inch suction disks. The tags were able to calculate various measurements inside the whale’s ecosystem, such as surface pressure and complex fluid forces around the whale, as well as GPS location and travel speed through tag vibration, all second and 720p’s 24 Resolution during video recording in frames.

“Fortunately, drag on the cockpits of a dimple-shaped airplane has been measured many times and we were able to help apply the knowledge that these remorse was experiencing drag,” said Grovey City’s co- Said bioflu Dynamics researcher Eric Anderson, author. College and guest investigator at the Woods Hole Oceanographic Institution. “But our study still required calculations that, for the first time, flow on a blue whale using computational fluid dynamics … It took an international team of biologists, programmers, engineers and a supercomputer to do this. ”

The team’s 211-minute video footage and whale tag data processed by researchers at the Barcelona Supercomputing Center captured a total of 27 remorse at 61 locations on the whale, which found Remora to be the most podding and the most hydrodynamically out of three. Were beneficial. The spots that separate the flow and flow are due to the different topographic features of the whale: directly behind the blowhole, behind and behind the dorsal fin, and behind the lateral field wing.

According to the team’s measurements, Anderson states that the shear force experienced by an average-sized remora behind a whale flying at an accidental speed of 1.5 m / s can be as low as 0.02 newton, half the force in the free stream above Drag. However, Anderson noted that Remora’s suction force at an average of 11–17 Newton is more than a match for the most intensive parking lot on the whale, its tail, where Remora experiences a shear force of about 0.14 Newton. And although the forces are high, the same holds true for larger remoraes that swim at much higher speeds in whale rides.

Eric Anderson said, “We found out that Remora’s suction discs are so strong that they can stick anywhere, even the tail streaks where drag is measured the strongest, but they like to go for an easier ride. We do.” “This saves them energy and makes life less expensive as they walk on hiccups and skim the surface of whales such as NASA’s probe on an asteroid or some mini-world.”

International study reveals the secret surfing life of remora hitchhiking on blue whales

Remora skimming when shifting to a more heterogeneous position on the whale: Stanford University and the Cascadia Research Collective. Image collected under NMFS permit # 16111.

Remorse Go Surf Up

The tag showed that to conserve energy while acquiring about their floating island, the remorse takes advantage of the whale’s physics by surfing inside a thin layer of fluid around the whale’s body, called a boundary layer. Where the team has found drag force up to 72% compared to a much more powerful free flow. Flemung says that fishes can lift 1 centimeter inward from their host in this layer, so that they can feed on whales at other low-drag social locations or engage their mates, sometimes skimping and changing directions , Or can repeatedly attach and release its suction disc over the body of the whale.

Flemang suspects that Remora are able to move freely from their accelerated hosts without completely peeling off, which can move about seven times faster than Remora, called the Venturi effect.

Fleming explained, “The behavior of skimming and surfing is surprising for a number of reasons, especially because we think that by staying one centimeter away from the whale’s body, they are taking advantage of the venturi effect and using suction forces Are. ” “In this narrow space between the remora and the whale, when the fluid is funneled into a narrow space, it moves at a high velocity, but its pressure is low, so it is not going to push the remora away, But that can actually lead to the host. ” It can float in free flow to pull the food cut and return to the boundary layer, but it takes too much energy to float in the free flow stream. ”

Along with uncovering new details of Remora’s hitchhiking proficiency, the team says they will continue to explore both the whale and the flow environment surrounding the mechanism by which specially adapted creatures such as remorse successfully host the animal. Tags attach to improve technologies and designs. Period of behavioral and ecological monitoring. The team is using its new insights to better inform Rimora’s favorite low-drag attachment locations where they can tag whales in upcoming studies.

“This is an extremely difficult process with the permission to study whales, with research rules and the opportunity to find animals, for all tags, usually close within 48 hours,” Flemung said. “If we can come up with a better way to collect data over a longer period of time through better tag placement or better technologies, it can really advance our learning of the species, and many other animals that connect to Remora . ”


The quest reveals that the remora fishes know when to stop a ride aboard their host


more information:
Flemung, B.E., Marras, S., Anderson, E.J., Lehmukhal, O., Mukherjee, A., Cade, Dey, Bechert, M., Nadler, J.H., Hauzoux, G., Wozcz, M., Emplo, H.E. Calambokidis, J., Friedlender, A.S., Goldbogen, J.A. (2020). Remora picks up where they cling to the blue whale. J. Exp. Bye. 223, jeb226654. DOI: 10.1242 / jeb.226654

Provided by the New Jersey Institute of Technology

Quotes: International Study Reveals the Secret Surfing Life of Referred Hitchhiking on Blue Whale (October 20, 2, October 2, October 2) from October 29, 2010 https://phys.org/news/2020-10-international-uncovers- secret-surfing-life.html

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