Mean and standard deviation of δ¹³C and δ¹⁵N values for <i>B</i>. <i>calamita</i> (filled circles; n = 21), <i>D</i>. <i>pictus</i> (empty circles) and the controlled diet (filled triangles; n = 21).

<p>Mean and standard deviation of δ¹³C and δ¹⁵N values for <i>B</i>. <i>calamita</i> (filled circles; n = 21), <i>D</i>. <i>pictus</i> (empty circles) and the controlled diet (filled triangles; n = 21).</p

Generalized least squares model for effects of the variables species (<i>D</i>. <i>pictus</i> and <i>B</i>. <i>calamita</i>), pond condition (sharing or non-sharing), and the interaction between the two on stable isotope values (δ ¹⁵N and δ ¹³C).

<p>Generalized least squares model for effects of the variables species (<i>D</i>. <i>pictus</i> and <i>B</i>. <i>calamita</i>), pond condition (sharing or non-sharing), and the interaction between the two on stable isotope values (δ ¹⁵N and δ ¹³C).</p

δ¹³C and δ¹⁵N values and standard ellipse areas for the isotopic niches of <i>B</i>. <i>calamita</i> (A) and <i>D</i>. <i>pictus (B)</i> in each pond under non-sharing conditions.

<p>δ¹³C and δ¹⁵N values and standard ellipse areas for the isotopic niches of <i>B</i>. <i>calamita</i> (A) and <i>D</i>. <i>pictus (B)</i> in each pond under non-sharing conditions.</p

δ¹³C and δ¹⁵N values and standard ellipse areas for <i>B</i>. <i>calamita</i> and <i>D</i>. <i>pictus</i> in the four ponds where the species coexist (A-D).

<p>δ¹³C and δ¹⁵N values and standard ellipse areas for <i>B</i>. <i>calamita</i> and <i>D</i>. <i>pictus</i> in the four ponds where the species coexist (A-D).</p

δ¹⁵N and δ¹³C descriptive statistics for two species in shared and non-shared ponds.

<p>These statistics were evaluated from original isotopic values (without specific diet discrimination correction).</p><p>δ¹⁵N and δ¹³C descriptive statistics for two species in shared and non-shared ponds.</p

Mean ± SD (and range) of δ¹⁵N and δ¹³C values, and isotopic discrimination factors (Δ¹⁵N and Δ¹³C) of <i>D</i>. <i>pictus</i> and <i>B</i>. <i>calamita</i>.

<p>t-test for discrimination factors between species.</p><p>*Significant values at p<0.0001.</p><p>Mean ± SD (and range) of δ¹⁵N and δ¹³C values, and isotopic discrimination factors (Δ¹⁵N and Δ¹³C) of <i>D</i>. <i>pictus</i> and <i>B</i>. <i>calamita</i>.</p

Mean standard isotopic ellipse area for <i>B</i>. <i>calamita</i> and <i>D</i>. <i>pictus</i> under sharing and non-sharing niche conditions.

<p>Mean standard isotopic ellipse area for <i>B</i>. <i>calamita</i> and <i>D</i>. <i>pictus</i> under sharing and non-sharing niche conditions.</p

Characteristics of selected ponds.

<p>Characteristics of selected ponds.</p

Distribution of <i>D</i>. <i>pictus</i> and the locations of the study ponds.

<p>(a) <i>D</i>. <i>pictus auritus</i> native (grey) and invaded (black) areas. (b) Study area. (c) and (d) locations of sampled ponds. Dots: <i>B calamita</i> non-shared ponds (P1 to P4); triangles: <i>D</i>. <i>pictus</i> non-shared ponds (P5 to P8); stars: shared ponds (P9 to 12). P1 to P12 correspond to Ponds 1 to 12 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130549#pone.0130549.t001" target="_blank">Table 1</a>. (e) Picture of Pond 2. (f) Adult <i>D</i>. <i>pictus</i>.</p