Unstable intraguild predation causes establishment failure of a globally invasive species

Abstract

Biotic resistance is often posited, but rarely known, to be the cause of invasion failure. Competition and predation are the most frequently identified processes that may prevent or limit the establishment of nonnative species. Interactions between nonnative and native species that involve intraguild predation (IGP) are very common in nature, although theory predicts most IGP systems should be unstable and lead to extinction. If this prediction is true, the frequency of invasion failures due to IGP may be underappreciated because of their fleeting nature and, thus, studies of unstable IGP systems are lacking, despite the opportunities they offer for understanding the factors affecting their unstable dynamics. We investigated a failed invasion involving an IGP relationship. In Florida, the guppy (Poecilia reticulata), a worldwide invader, fails to establish in the presence of eastern mosquitofish (Gambusia holbrooki). We tested whether and how resident mosquitofish cause guppy invasion failure using replicated mesocosm and aquarium trials. Both the predator and competitor components of the IGP relationship were strongly asymmetrical, with large impacts on guppies. We identified two effects, direct consumption of neonates and aggressive interference competition, that limited survival and recruitment. The highly unstable nature of this IGP relationship is the primary cause of the failure of the guppy to establish in Florida. Our study shows that the transient nature of an ephemeral IGP relationship can yield important insights into the underlying causes of invasion failure, including the role of strong biotic resistance.

Resistance from a resident heterospecific affects establishment success of a globally invasive freshwater fish

“…Surviving founders are included on this figure. Units are ordered by mesocosm area from smallest (left) to largest (right)Tuckett et al, 2021). Although our findings support the predictions that a strongly asymmetrical IGP relationship may preclude successful establishment, such an outcome may not be inevitable.…”

“…This is the case in south Florida, where multiple releases of guppies and other small fishes have failed to establish and spread in spite of appropriate abiotic conditions (Tuckett et al, 2017). There, IGP by the native eastern mosquitofish, Gambusia holbrooki , prevents establishment of small‐bodied fishes, including guppies (Thompson et al, 2012; Tuckett et al, 2021). Although our findings support the predictions that a strongly asymmetrical IGP relationship may preclude successful establishment, such an outcome may not be inevitable.…”

Advertent domestication attenuates the influence of propagule pressure

“…We focused on ubiquitous and dominant native species because they occur in layered communities as the ditches and streams receiving aquaculture e uents become larger systems capable of supporting larger, predatory sh species (Hill and Tuckett 2018). We note a very strong effect of mosquito sh on swordtail abundance and previous studies have identi ed two mechanisms, consumption of neonates and aggression directed at adults (Hill et al 2011;Thompson et al 2012;Tuckett et al 2021a). Increasing sh diversity by adding reproducing sun sh had little additive effect on numbers, but resulted in larger average body size of prey.…”

“…Biotic resistance theory has a long history of testing and has been commonly identi ed as a relationship between diversity and invasibility (Elton 1958; Levine and D'Antonio 1999); other interpretations emphasize strongly-interacting species (Henriksson et al 2015;Tuckett et al 2021a), especially by native predators (Rogers et al 2016;Yorisue et al 2019). These latter studies emphasize the increased probability of including a species that is a strong resistor to invasion as diversity increases (Henriksson et al 2015).…”

The effect of phenotypic heterogeneity on behaviours linked to invasive success

“…Further, the solitary bee ( Lasioglossum leucozonium ) invaded North America despite a small founding population (Zayed et al, 2007); and the movement of a small number of individuals along the Suez Canal is believed to have facilitated the lionfish ( Pterois volitans ) invasion of the Mediterranean (Bariche et al, 2017). Furthermore, even after frequent introductions many introduced species still fail to become established (Chapple et al, 2012; Tuckett et al, 2021; Zenni & Nunez, 2013). It is, then, clear that other factors besides the number and frequency of introductions are at play in determining the outcome of an invasion ‐ for example, the suitability of the abiotic and biotic environment and the traits of the introduced species themselves (Chapple et al, 2012; Deacon & Magurran, 2016; Drenovsky et al, 2012; Garcia‐Berthou, 2007; Lloret et al, 2005).…”