Upstream guppies (Poecilia reticulata, Peters, 1859) go against the flow

Abstract

Guppies (Poecilia reticulata Peters 1859) in lakes and from captive-bred populations are predicted to show little rheotaxis compared to conspecifics in a stream environment that are regularly exposed to flash floods associated with involuntary downstream migration. Here we test this hypothesis using an artificial stream, examining guppies of two wild riverine populations, one lake population, and one ornamental strain. Guppies from the most upstream riverine habitat show the most pronounced rheotaxis and are less likely to be swept downstream during flooding events. However, there is no significant difference between guppies from the lowland riverine habitat, the Pitch Lake and ornamental strain. We propose that station-keeping behaviours are most strongly selected in the upstream population because large spatial differences exist in ecology and environment between up-and downstream habitats. Given that these sites are separated by barrier waterfalls that prevent compensatory upstream migration, natural selection operates particularly strong against upstream guppies that have been displaced downstream during flooding events. Resumo: Populações de guppies (Poecilia reticulata Peters) que vivem em lagos e em cativeiro podem demonstrar menos reotaxia em comparação com populações que habitam rios e que estão frequentemente expostas a enchentes e que provocam a migração involuntária para jusante. Neste trabalho, vamos testar esta hipótese num rio artificial utilizando guppies de duas populações selvagens que habitam em rios, uma população que habita em lagos, e uma linhagem ornamental. Os resultados demonstram que os guppies de rios que provêm de localidades a montante demonstram maior reotaxia, diminuindo assim probabilidade de serem arrastados para jusante em períodos de enchentes. No entanto, não foram encontradas diferenças significativas entre guppies de localidades a jusante, do lago Pitch ou ornamentais. Este resultado pode dever-se ao facto de existirem grandes diferenças ecológicas entre os habitats localizados a jusante e a montante dos rios. Devido ao facto de estas localidades estarem separadas por cachoeiras, impossibilitando a migração rio-acima, a seleção natural poderá estar a actuar contra guppies que sejam arrastados rio abaixo durantes os períodos de cheias Palavras-chave: Guppy (Poeciliareticulata), reotaxia, piscina comportamento, migração, seleção natural. Neotrop., vol. 12, no. 3 were conducted because guppies infected with Gyrodactylus spp. are more likely to be swept downstream than uninfected counterparts van (van Oosterhout et al. 2007a). Briefly, guppies were anaesthetised with 0.02% MS222 and using a stereo-microscope and fibre optic illumination, gyrodactylids were removed with watchmaker's tweezers. Fish were clean of all ectoparasites and showed no symptoms of disease in the two weeks prior to the experiment. The behaviour of guppies was recorded in an artificial stream (length × width × depth = 112.2 × 12 × 4.0 cm 3 ). The water flow rate was 15.4 (±1.2) cm.s -1 , compar...

Asymmetric Isolation and the Evolution of Behaviors Influencing Dispersal: Rheotaxis of Guppies above Waterfalls

“…The overall average tendency was still toward some net downstream displacement; yet based on comparisons with an inanimate prop, this displacement was on average 41 times less than expected if the guppies had not actively aligned against the current. Hence, our results confirm that guppies located in the upstream reaches of rivers express strong positive rheotaxis: that is, a strong tendency to swim against the flow [48].…”

“…Thus, as seen in numerous other fishes (review in [22]), the downstream origin of the Turure fish was likely to dictate initially weak positive rheotaxis, a supposition supported by the dramatic effect their downstream movement had on native populations [15,31,33]. Further support comes from Mohammed et al (2012), who found that guppies located in lower reaches of a stream were more likely to be swept downstream than guppies located further upstream [48]. It therefore seems likely that the current strong positive rheotaxis in the Turure River reflects at least some (and perhaps substantial) contemporary evolution following their introduction more than 60 years ago.…”

Differences in rheotactic responses contribute to divergent habitat use between parapatric lake and stream threespine stickleback

“…; Mohammed et al. ). Importantly, the differences documented here are specific to performance in flowing water; lake and stream fish did not differ in swimming performance in still water.…”

Interpopulation variation of behavioural and morphological traits that affect downstream displacement of the juvenile white‐spotted charr Salvelinus leucomaenis

“…Blondel et al . (2020) speculated that high rheotaxis in P. reticulata might have evolved in above‐waterfall habitats to allow individuals to remain in their habitats (see also Mohammed et al ., 2012). In recent years, increasing attention has been paid to phenotypic shifts in upstream fish populations caused by the presence of migration barriers (Zarri et al ., 2022).…”