Browsing by Author "Patrao, Claudia"
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- Different diversity-dependent declines in speciation rate unbalances species richness in terrestrial slugsPublication . Lopes Da Cunha, Regina; Patrao, Claudia; Castilho, RitaTwo genera of terrestrial slugs (Arion and Geomalacus) display a striking disproportion in species richness in the Iberian Peninsula. While there are 17 Iberian endemic species in Arion, morphological criteria only recognize four species within Geomalacus. Sequence data were used to test whether these differences could result from: (1) cryptic diversity within Geomalacus; (2) an earlier origin for Arion (older clades are expected to accumulate more species); (3) distinct patterns of diversification rates (higher initial speciation rates in Arion), and (4) some combination of the above factors (e.g., an older clade with higher speciation rates). Species delimitation tests based on mitochondrial and nuclear data revealed eight cryptic lineages within Geomalacus that lessened the asymmetry; nevertheless, the disparity required further investigation. No meaningful differences in crown group ages of each recovered clade were found. Regardless the different premises of the two equally plausible diversification models (similar initial speciation rates vs. higher initial speciation rates in Geomalacus), both coincide on diversity-dependent diversification for the two groups but weaker rate declines in Arion best explains the observed asymmetry in species richness. Also, the broader environmental tolerance combined with a faster dispersal and wider distribution may have represented an evolutionary advantage for Arion.
- Habitat suitability modelling of four terrestrial slug species in the Iberian Peninsula (Arionidae: Geomalacus species)Publication . Patrao, Claudia; Assis, J.; Rufino, MM; Silva, Goncalo; Jordaens, Kurt; Backeljau, Thierry; Castilho, RitaEcological niche modelling (ENM) determines habitat suitability of species by relating records of occurrence to environmental variables. Here, we investigated habitat suitability of four terrestrial slugs of the genus Geomalacus from the Iberian Peninsula using ENM. The potential distribution of these species was estimated using maximum entropy modelling. For this we used published presence records, together with observations from our fieldwork, and 10 layers of environmental variables in a crossvalidation design using ` minimum predicted area' as a measure of success. For each species, the models predicted distributions with high accuracy, while restricting predictions to minimum areas. Precipitation, and to a lesser extent temperature, were the most important variables to predict the distributions of the four species. We then compared the predicted distributions with the currently known distributions. For G. anguiformis and G. maculosus the predicted distributions included the known distributions, but also nearby mountain areas where these species have not previously been found. For G. malagensis and G. oliveirae the models predicted much wider distributions. Subsequent dedicated fieldwork could not confirm the presence of G. oliveirae in the newly predicted areas. Conversely, G. malagensis was found at five new and distant localities, including areas in Portugal where the species has not previously been recorded.