The response of amphibian communities to fish and habitat features in Mediterranean permanent ponds

Abstract

Generalized linear models were used to test the effect of fish, using ponds with and without fish and habitat features as covariates, on richness and abundance of amphibian species. Five fish species and six amphibian species were recorded in 60 permanent ponds located in central Italy. The choice of covariates (macrophyte cover and pond surface area) was made after studying the correlations. The richness of amphibian species was not significantly affected by fish presence or macrophyte cover, in line with previous studies, since almost all the fish species were non-predatory. However, abundance of urodeles (newts) was negatively affected by fish and positively affected by macrophyte cover. Although fish may strongly influence the abundance and composition of amphibian communities, the results indicate that the cover of aquatic macrophytes may increase the available habitat for amphibians and therefore their abundance. Anuran species preferred ponds where fish were present, since both groups preferred larger ponds. Concordance between fish and amphibian species composition was not found by the Mantel and Partial Mantel tests. This indicates that the fish assemblages do not predict which amphibian species occur in the pond.

Amphibians forgo aquatic life in response to alien fish introduction

“…Along with the terrestrial habitat, aquatic microhabitats are essential environmental features to sustain newt populations. Field ecological studies have shown that amphibians, such as newts, are present in ponds with plentiful vegetation, which provides shelter for both adults and larvae, and substrate for spawning (Hartel et al, 2007;Joly, Miaud, Lehmann & Grolet, 2001;Landi, Piazzini & Saveri, 2014). In this study, we found that the availability of aquatic shelter allows half of the newt population (53%) to coexist with fish, whereas almost all newts (87%) left the water when they had no aquatic shelter.…”

Environmental DNA metabarcoding elucidates patterns of fish colonisation and co‐occurrences with amphibians in temperate wetlands created for biodiversity

“…All our sampled wetlands, however, were larger than 0.5 ha, while the suggested optimal size for many amphibian species may be as small as 0.1 ha (Semlitsch et al, 2015; but see Bancila et al, 2017). Therefore, similarly to studies involving larger ponds (Landi et al, 2014;Porej & Hetherington, 2005), we may have failed to detect such a preference for the smallest wetlands as these were not available in our study area. Furthermore, as most wetlands had fish, probably because they were large enough not to dry out entirely or freeze, we may lack relevant variation in wetland size to detect the amphibian preference for smaller, fish-free wetlands.…”

Biological Invasions in Fresh Waters: Micropterus salmoides, an American Fish Conquering the World

“…In addition to competing with other fish such as Esox lucius, a native predator of higher commercial value [19,98], the bass has been reported to negatively affect amphibian species of conservation interest [131,207], representing an indirect source of economic loss. Indeed, some of the species affected by bass (e.g., the Italian crested newt Triturus carnifex; [131,141]) are not only important for nature tourism, but are also the subject of funded conservation and research programs, as they are particularly vulnerable to changes in both aquatic and terrestrial habitats [208].…”