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Morphological and life-history responses of anurans to predation by an invasive crayfish: an integrative approach.

Nunes AL, Orizaola G, Laurila A, Rebelo R - Ecol Evol (2014)

Bottom Line: As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them.These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles.The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities.

View Article: PubMed Central - PubMed

Affiliation: Centro de Biologia Ambiental, Departamento de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa Lisbon, Portugal ; Animal Ecology/Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University Uppsala, Sweden.

ABSTRACT
Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator-prey interactions following biological invasions.

No MeSH data available.


Mean ± SE values of relative warp 1 (RW1) representing tadpole shape of the nine anuran species in the presence of different predator treatments. Drawings placed on the right-hand side of each graph show the shape of larvae representing the extreme positive (black) and negative (gray) scores of RW1.
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fig01: Mean ± SE values of relative warp 1 (RW1) representing tadpole shape of the nine anuran species in the presence of different predator treatments. Drawings placed on the right-hand side of each graph show the shape of larvae representing the extreme positive (black) and negative (gray) scores of RW1.

Mentions: All morphological analyses were conducted on relative warp scores and independently for each of the nine studied species. The body shape of tadpoles was examined using the first relative warp yielded by the geometric morphometrics analyses (RW1) which accounted, on average, for over 50% of the total morphological variance (Fig. 1; see Orizaola et al. (2012) for a similar approach). We analyzed the effects of the different predator treatments on tadpole morphology using univariate analyses of variance (ANOVAs) with type III sum of squares, where RW1 scores were the dependent variable describing tadpole morphology. Post hoc analyses were performed using Tukey HSD tests.


Morphological and life-history responses of anurans to predation by an invasive crayfish: an integrative approach.

Nunes AL, Orizaola G, Laurila A, Rebelo R - Ecol Evol (2014)

Mean ± SE values of relative warp 1 (RW1) representing tadpole shape of the nine anuran species in the presence of different predator treatments. Drawings placed on the right-hand side of each graph show the shape of larvae representing the extreme positive (black) and negative (gray) scores of RW1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4020706&req=5

fig01: Mean ± SE values of relative warp 1 (RW1) representing tadpole shape of the nine anuran species in the presence of different predator treatments. Drawings placed on the right-hand side of each graph show the shape of larvae representing the extreme positive (black) and negative (gray) scores of RW1.
Mentions: All morphological analyses were conducted on relative warp scores and independently for each of the nine studied species. The body shape of tadpoles was examined using the first relative warp yielded by the geometric morphometrics analyses (RW1) which accounted, on average, for over 50% of the total morphological variance (Fig. 1; see Orizaola et al. (2012) for a similar approach). We analyzed the effects of the different predator treatments on tadpole morphology using univariate analyses of variance (ANOVAs) with type III sum of squares, where RW1 scores were the dependent variable describing tadpole morphology. Post hoc analyses were performed using Tukey HSD tests.

Bottom Line: As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them.These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles.The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities.

View Article: PubMed Central - PubMed

Affiliation: Centro de Biologia Ambiental, Departamento de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa Lisbon, Portugal ; Animal Ecology/Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University Uppsala, Sweden.

ABSTRACT
Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator-prey interactions following biological invasions.

No MeSH data available.