Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model

Abstract

Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine–Main–Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris) and one to the Cyprinidae family (Romanogobio belingi). These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae), Barbatula barbatula (Nemacheilidae), Cottus perifretum, and C. rhenanus (Cottidae). Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens). These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM). The FFM was used to predict the trophic profile (TP) of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris) had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between species, it provides a tool to support horizon scanning and rapid risk assessments of alien species.

In a Pinch: Mechanisms Behind Potential Biotic Resistance Toward Two Invasive Crayfish by Native African Freshwater Crabs

“…In Lake Kariba the trophic niche of crayfish differed with size class, wherein macroinvertebrate consumption increased with size, which could potentially be due to the positive relationship between mass and closing force (Marufu et al, 2018). Comparative functional morphology of decapod chelae and feeding apparatus should thus be incorporated into invasion risk assessments as ecomorphology can help to predict impact (Nagelkerke et al, 2018).…”

Partial decoupling between exotic fish and habitat constraints remains evident in late invasion stages

“…However, reproductive polyphily and adaptation to a wide range of turbidity were more dominant in native communities over the same area, indicating that perhaps not all generalist traits are equally relevant to determine invasion success. The timeline of invasion processes could partly explain this complex result: early invasion phases could be spearheaded by true generalists, but on the long run more specialized species can also be introduced and spread in the area, overriding some of the overall invasion patterns (Nagelkerke et al 2018). As this area is in a late invasion stage (Milardi et al 2018a), what we observe could be the result of the complex interactions between species-specific introduction timing and mechanisms of dispersal and interaction with native species, as well as the overall outcome of longer-term environmental selection of exotic communities.…”

Vectors for the development of high-tech industrial aquaculture

“…In many respects, it is not inferior to fish from natural reservoirs, and in some cases it also surpasses it with respect to a set of parameters of nutritional value. Fish grown under human control can be programmed to have the desired content of vitamins, amino acids and other biologically active substances, making it a product of functional nutrition [3,4].…”