CONICET | Buscador de Institutos y Recursos Humanos

Skeletochronology, counting the number of lines of arrested growth (LAGs) in cross-sections of phalanges obtained by toe-clipping, has become a widely used tool for age estimates in amphibians. We used skelotochronological methods to describe the age structure of a Leptodactylus latinasus population from northeast Argentina (Corrientes province, 27°25'51.10"S, 58°44'42.50"W). We also analyzed the body size and age implications for reproductive traits (clutch weight, ovum size and clutch size; CW, OS and CS, hereafter). We captured a total of 51 L. latinasus (Male: n = 34, Female: n = 17) from spring 2007 to autumn 2008. We were able to determine the age in 12 out of 34 males and 12 out of 17 females captured. The minimum and maximum ages found were 1 and 3, respectively. We did not find a difference in mean age between the sexes (t-test = 1.82, df = 22, P = 0.082). Mean and SD of LAGs and phalangeal perimeter in microns were: LAG1 = 118 ± 16.3 n = 8; LAG2 = 176 ± 31.6 n = 3; LAG3 = 182 n = 1; PER = 193.6 ± 40.8 n = 24. There was no significant effect of sex on body weight, SVL and hind limb length (Wilks ë = 0.867, F3,42 = 2.129, P = 0.11), which demonstrates that there is no sexual dimorphism in this specie. Mean and SD of reproductive traits in 10 out of 17 females analyzed were: CW = 0.204 g ± 0.09, OS = 1.19 mm ± 0.14, CS = 224.3 ± 51.4. CW showed a positive relationship with CS (r2 = 2.85, P < 0.05, n = 10) and ES (r2 = 0.787, P < 0.001, n = 10). We found no significant correlation between reproductive traits and body size or age in L. latinasus (minimum P value of all relationship analyzed = 0.201). To estimate the relative effect of age on reproductive traits, partial correlation was analyzed, which showed that age had no significant effect on reproductive traits.