Research groups at Hokkaido University and the Hokkaido Prefectural Research Organization have discovered that organisms (hosts) parasitized by other organisms take rational escape behavior according to their physical strength.Ironically, numerical simulations have also shown that escape behavior leads to further epidemics of parasites.
Animals that have been infected with parasites in nature (infected individuals) are forced to make a tough choice as to whether they should escape or escape.While we want to escape the source of infection, migration in nature is a high risk.In such a dilemma, it was unclear what kind of escape behavior the infected individual would take.
This time, the group investigated the behavior of a total of 215 juvenile cherry salmon that had been treated with parasitism and juvenile cherry salmon that had not been treated. I found.In other words, he discovered a rational behavior that "only infected individuals with physical strength escape far away."
Furthermore, when the effect of this movement behavior on the spread of parasites was examined by numerical simulation, ironically, the parasite population survived four times longer than when the movement behavior of unparasitic fish was assumed. However, it was shown that it invaded and settled in an area 4 times larger.This result is due to the achievement of the exquisite division of roles that "small fish that do not escape promote" breeding of parasite groups on the spot "and large fish that escape promote" spread to new places "." Conceivable.
These detrimental phenomena may occur in other organisms, and are expected to be applied to the prediction of disease spread in wild animals in the future.
Paper information:[Proceedings of the Royal Society B: Biological Sciences] Parasite infection induces size-dependent host dispersal: consequences for parasite persistence
