RT Journal Article
SR Electronic
T1 Consistent behavioural syndromes across seasons in an invasive freshwater fish
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.03.03.974998
DO 10.1101/2020.03.03.974998
A1 J Lukas
A1 G Kalinkat
A1 FW Miesen
A1 T Landgraf
A1 J Krause
A1 D Bierbach
YR 2020
UL http://biorxiv.org/content/early/2020/03/04/2020.03.03.974998.abstract
AB The linkage between behavioural types and dispersal tendency has been suggested to be a widespread phenomenon and understanding its mechanisms has become a pressing issue in light of global change and biological invasions. Here, we investigate whether individuals who colonize new habitats exhibit a certain set of behavioural types that differs from those remaining in the source population. We focussed on a feral population of guppies (Poecilia reticulata) that is assumed to undergo a yearly (re)colonization process. Guppies are among the most widespread invasive species in the world, but in temperate regions these fish can only survive in thermally altered freshwaters due to their tropical origin. The investigated population has sustained in a thermally-altered stream in Germany for over 50 years, where they find year-round suitable water temperatures around a warm-water influx. However, in warm seasons, peripheral parts of the warm-water flume become thermally accessible and may be colonized. We sampled fish from the source population and from a winter-abandoned downstream site in March, June and August. Fish were tested for boldness, sociability and activity involving open field tests as well as interactions with a biomimetic robot as social partner. Guppies differed consistently among each other in all three traits. Behavioural trait expression in the source population differed across seasons, however, we could not detect differences between source and downstream populations. Instead, all sampled populations showed a remarkably stable behavioural syndrome between boldness and activity despite strong changes in water temperatures across seasons. We conclude that random drift (as opposed to a personality-biased dispersal) is a more likely dispersal mode for guppies, at least in the investigated stream system. In the face of highly fluctuating environments, guppies seem to be extremely effective in keeping their behavioural expressions constant, which could help explain their successful invasion and adaptation to disturbed habitats.