Relative importance of exotic species traits in determining invasiveness across levels of establishment: Example of freshwater fish

Abstract

Understanding the factors responsible for the success of exotic species is a prevalent issue in invasion biology. Although the ecological traits of exotic species are known to play a major role, it is still unknown which traits are responsible for the different dimensions of invasiveness among vertebrates. Here, we assessed the ecological, morphological and behavioural profile of 222 exotic freshwater fish along different levels of establishment, defined by the number of basins in which the exotic species are established and the location of establishment. Using a trait‐based multidimensional space complemented by a trait‐by‐trait analysis, we attempted to classified exotic vertebrates given their intrinsic traits across establishment levels ranging from species with low establishment to super‐established species. We found that fish with low establishment were clustered in the trait space, showing similar traits characterized by low‐temperature amplitude, no parental care and zoobenthic diet. By contrast, super‐established fish had a broader range of functional strategies, with a high proportion of species having multiple diets and a high level of parental care. Overall, fish with low establishment had low functional overlap with other fish at higher levels of establishment. Our findings highlight the importance of considering trait variability in the species' level of establishment to more accurately anticipate their ability to establish and spread. Read the free Plain Language Summary for this article on the Journal blog.

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

“…For example, Oreochromis mossambicus and Oreochromis niloticus were introduced to 97 and 94 countries, respectively, and are bearers with at least four different diets (Froese and Pauly 2019). This result supports our initial hypothesis, as these two characteristics have already been highlighted in previous studies, though only at the state or country scales and/or for the establishment step (Marchetti et al 2004a in California;Tonella et al 2018 in Brazil;Chan et al 2021 in Singapore; Lawson and Hill 2022 in Peninsular Florida, Bernery et al 2023). Nonetheless, the role played by parental care in the introduction step of the invasion process has not yet been reported, with the underlying mechanisms remaining to be elucidated (e.g., Marchetti et al 2004a).…”

“…Moreover, generalist diets allow introduced species to adapt to different environments, and thus, allow establishment in a wider range of environments (Tonella et al 2018). In a recent study on 222 non-native fishes, Bernery et al (2023) reported similar results at the global scale, finding that varied diets, higher temperature range within the native ranges, and greater levels of parental care were associated with widely established fishes.…”

“…Despite some gaps and incompleteness, it gathers most of the current knowledge on fish species characteristics and human uses. FishBase has been widely used, notably in global studies determining characteristics of invasive fishes (e.g., Ruesink 2005;Bernery et al 2023). Herein, we used FishBase to gather the diet, reproductive guild, human use, and introduction pathways that are fairly well informed for most fish species (Blanchet et al 2010;Hirsch et al 2021;Su et al 2023).…”

Decadal‐scale regional variability in monitoring efforts significantly influences fish diversity trends in the Euphrates and Tigris catchments, Türkiye

“…Compounding this issue, the invasion of non‐native species poses another major threat to the native fish fauna due to competitive advantages (Haubrock et al, 2021). Thus, non‐native species often outcompete native species for resources (Top Karakuş et al, 2021), but they may also alter local ecosystems, sometimes irreversibly (Bernery et al, 2023). According to recent studies, the number of non‐native species in the Euphrates and Tigris catchments has surpassed 30 established non‐native species (Esmaeili, 2021), continuing to increase with new introductions (Kırankaya & Ekmekçi, 2021).…”

Sustainability in agricultural production and natural resource management T-I Biotechnology and Agricultural Sciences

“…A viable alternative to reduce the risk that aquaculture poses to biodiversity is the diversification of cultivable species (Bernery et al, 2023;Thomas et al, 2021). This strategy involves prioritising the use of regional species that can be cultivated in aquaculture systems, thus promoting localised production.…”