Stable isotopes characteristics of the fish species within their native and introduced ranges

Stable isotopes characteristics of the fish species within their native and introduced range

donnees_Dryad

donnees_Drya

The repeatability (R) of behavioural measures in juvenile pike (n = 34) across context using one trial of each treatment conducted closest in time: (a) trials 1 (n = 3), (b) trials 2 (n = 3), (c) trials 3 (n = 3), (d) trials 4 (n = 3), and (e) all trials (n = 14).

<p>Generalised linear mixed-effects and linear mixed-effects models (rptR package in R, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031619#pone.0031619-Grimm1" target="_blank">[33]</a>) with fish identity fitted as random effect and the behavioural measure as dependent factor were used for calculating repeatabilities, standard errors, 95% confidence intervals (CIs) and P-values. Latency to prey attack and swimming activity were log-transformed to achieve normality.</p

Mean number of prey captured per individual pike (n = 34) in the experimental treatments.

<p>(a) Control versus competitor, (b) control versus predator, (c) competitor versus predator treatments. Correlations were investigated using Spearman's ranking tests (rs,*** P<0.001).</p

Mean number of prey captured in the predator treatment per individual pike (n = 34) and their metrics.

<p>(a) Specific growth rate, (b) initial body mass, (c) final body mass. Correlations were investigated using Spearman's ranking tests.</p

Supplementary materials from The functional syndrome: linking individual trait variability to ecosystem functioning

Phenotypic variability is increasingly assessed through functional response and effect traits, which provide a mechanistic framework for investigating how an organism responds to varying ecological factors and how these responses affect ecosystem functioning. Covariation between response and effect traits has been poorly examined at the intraspecific level, thus hampering progress in understanding how phenotypic variability alters the role of organisms in ecosystems. Using a multi-trait approach and a nine-month longitudinal monitoring of individual red-swamp crayfish (<i>Procambarus clarkii</i>), we demonstrated that most of the measured response and effect traits were partially stable during the ontogeny of individuals. Suites of response and effect traits were associated with a response syndrome and an effect syndrome, respectively, which were correlated to form a functional syndrome. Using a bioenergetic model, we predicted that differences in the response syndrome composition of hypothetical populations had important ecological effects on a key ecosystem process (i.e. whole-lake litter decomposition) to a level similar to those induced by doubling population size. Demonstrating the existence of a functional syndrome is likely to improve our understanding of the ecological impacts of phenotypic variation among individuals in wild populations across levels of biological organization, and the linkage between ecosystem and evolutionary ecology

The repeatabilities (R) of behavioural measures in juvenile pike (n = 34) within each experimental situation: (a) control (no risk), (b) competition (low risk), (c) predation (high risk).

<p>Generalised linear mixed-effects and linear mixed-effects models (rptR package in R <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031619#pone.0031619-Grimm1" target="_blank">[33]</a>) with fish identity fitted as random effect and the behavioural measure as dependent factor were used for calculating repeatabilities, standard errors, 95% confidence intervals (CIs) and P-values. Latency to prey attack and swimming activity were log-transformed to achieve normality.</p

Mean behavioural measurements (± SE) of juvenile pike (n = 34) in each trial of the (a) control, (b) competitor and (c) predator treatment.

<p>Mean behavioural measurements (± SE) of juvenile pike (n = 34) in each trial of the (a) control, (b) competitor and (c) predator treatment.</p

Stable isotope values of European catfish and the putative prey.

<p>δ¹³C and δ¹⁵N values (‰) of each individual (n = 14) and the putative aquatic (fish, n = 9 and crayfish, n = 3) and terrestrial (pigeon, n = 6) prey are displayed. The large symbols for each prey represent the mean value (± SD).</p

European catfish displaying beaching behavior to capture land birds.

<p>Several individuals were observed swimming nearby the gravel beach in shallow waters where pigeons regroup for drinking and cleaning (large picture). One individual is seen approaching land birds and beaching to successfully capture one (small pictures).</p