Young salmon may perhaps leap to ‘oust the louse’ — ScienceDaily
A analyze by Simon Fraser College aquatic ecologists Emma Atkinson and John Reynolds reveals that young salmon may well jump out of water to take away sea lice.
“Strategies about why fish leap incorporate finding in excess of hurdles all through their upstream migration as adults, catching meals and avoiding predators,” says Atkinson.
“However, these explanations may possibly not apply to younger salmon due to the fact their diet regime is composed just about exclusively of underwater zooplankton and their tendency is to scatter rather than leap when escaping from predators.”
Atkinson hypothesized that the leaping behaviour could be the fish’s way of eradicating parasitic sea lice, which is a widespread affliction for wild and penned salmon off the B.C. coastline. Hefty sea-louse infestation is correlated with lessened development, impaired swimming and aggressive foraging capability for young salmon.
To exam her speculation, Atkinson and her group caught wild juvenile sockeye salmon during their coastal migration absent from the Fraser River. They held the fish in movement-via internet-pen enclosures, half of which ended up included with netting to reduce leaping and the other 50 percent were being left uncovered to let leaping. Immediately after a few times, the group counted the lice on every fish.
The scientists found that, on common, the salmon that had been permitted to leap in the uncovered pen had 22 for each cent fewer sea lice in comparison to people that were not authorized to leap in the included pen.
The researchers also identified that it may acquire more than 50 leaps for a youthful salmon to dislodge a sea lice, which Atkinson acknowledges is a significant amount of power to expend. She claims these costs could be offset by the benefits of productively taking away sea lice, but will have to be investigated in one more analyze.