Search

A description of a new troglobitic Lepidocampa species from La Réunion Island is given. Certain taxonomical attributes of this new species suggest that the subgenera traditionally established within Lepidocampa genus should be eliminated. Next, the main troglobiomorphic features in campodeid diplurans (large body size, long appendages, high number of antennomeres and cercal articles, presence of lateral crests and laminar processes on telotarsus, high number of complex antennal sensilla, and absence of a seasonal reproductive cycle) are reviewed in order to clarify their adaptive value to the subterranean milieu. Finally, the growth of cerci in relation to body size in campodeids is explored using data compiled from the literature and standardised major axis regression analysis. A large body and long appendages may be especially relevant in campodeids when dwelling in the subterranean fissures. Yet, the allometric pattern of cerci length in relation to body size among subfamilies points to a phylogenetic signal, probably related to the habitat preferences of each group, and which suggests the importance of the physical space in which the different families preferentially dwell. [ABSTRACT FROM AUTHOR]

Abstract: Non-indigenous plant species have been frequently reported as successful invaders in island environments, changing plant community composition and structure. This is the case of the sweet pittosporum (Pittosporum undulatum), native from Australia, which is one of the most successful plant invaders in the Azores archipelago. Data extracted from recent forestry inventories were used to model and map the potential distribution of P. undulatum in São Miguel, the larger island of the Azores. Current distribution of P. undulatum is related to climate, altitude and some human activity effects. Further analysis of the areas under risk of invasion showed that protected areas are under potential threat, although only a few native forest remnants seem to be threatened due to future expansion of P. undulatum, since the current distribution of these native communities has been reduced due to clearing and competition with invasive plants. We discuss the threats that any further expansion of the species will represent for low-altitude native forests, as well as the utility of species distribution models in the assessment of the areas under risk of invasion. [Copyright &y& Elsevier]

ABSTRACT: For many applications the continuous prediction afforded by species distribution modeling must be converted to a map of presence or absence, so a threshold probability indicative of species presence must be fixed. Because of the bias in probability outputs due to frequency of presences (prevalence), a fixed threshold value, such as 0.5, does not usually correspond to the threshold above which the species is more likely to be present. In this paper four threshold criteria are compared for a wide range of sample sizes and prevalences, modeling a virtual species in order to avoid the omnipresent error sources that the use of real species data implies. In general, sensitivity–specificity difference minimizer and sensitivity–specificity sum maximizer criteria produced the most accurate predictions. The widely-used 0.5 fixed threshold and Kappa-maximizer criteria are the worst ones in almost all situations. Nevertheless, whatever the criteria used, the threshold value chosen and the research goals that determined its choice must be stated. [Copyright &y& Elsevier]

ABSTRACT: Biological correlates of species description dates can be used to predict the characteristics of yet-to-be-described species. Such information can be useful in the planning of biodiversity field surveys. This paper explores the influence of five factors—body size, geographic range size, geographic location, habitat and number of congeners—on the probability of description of endemic Iberian ground-beetles, and attempts to identify the effects of each factor, alone or in combination, through variation partitioning. Small-bodied and hypogean species were found to have been described later, as were those with smaller geographic ranges, while the number of congeners did not significantly affect description date. Additionally, Eastern hypogean species were described earlier than Western ones because of major lithology differences from east to west in the Iberian Peninsula, and concomitant geographic taxonomic bias. However, effects of each factor alone are quite small in comparison with effects of the combination of factors, due to their considerable correlation. Thus, “rarity”, in its broadest sense, has been the determining factor of date of description of endemic Iberian ground-beetles. Previously, the technical difficulty encountered in the study of rare species retarded their description, whereas now they have become a “fashionable” object of study among carabidologists, due to the possibility of rapid publication. In order to improve the incomplete checklist of Iberian ground beetles it would be necessary to focus sampling efforts on marginal habitats and hypogean fauna. [Copyright &y& Elsevier]

Abstract: The capacity of short-term sampling to provide reliable estimates of annual spider assemblages (Araneidae and Thomisidae) present in a Mediterranean site was analyzed, along with the contribution of juvenile data on estimations of spider species richness. A standardized year-long sampling protocol in a one-square-kilometer plot in central Spain yielded reliable Araneidae and Thomisidae inventories. To compare sampling design efficiencies, the degree of completeness of collected annual inventories was estimated, along with an “optimal sampling” selection of months, i.e. the minimum number of months indicating most accurately the number of species present throughout the year. The completeness of spring-month sampling, as well as that of every month, was also estimated. Calculations both included and excluded immature stages. When multiple localities must be sampled and fieldwork minimized, a 1-month spring sampling protocol reasonably estimates the entire spring fauna, allowing effective comparisons between sites during the richest period. Our results indicate that juveniles must be included in the sample in order to obtain reliable estimates of species richness, and they should be stored apart from adults in order to analyze them separately as advances in their identification are achieved. [Copyright &y& Elsevier]

• The two L. boscai lineages differed in their predicted potential distribution. • Intraspecific differences were independent of the distribution model algorithm used. • Lineages have a limited niche overlap and occur in different environmental niches. • Intraspecific variation improved lineage based-distribution models predictivity. Species distribution models (SDMs) treat species as a single unit, neglecting intraspecific variation. Few studies address the impact of intraspecific variation on SDM performance, and none of them account for the well-known inter-algorithm variability in prediction performance. The endemic Iberian amphibian Lissotriton boscai comprises two geographically highly structured phylogenetic lineages, which allowed us to explore how intraspecific variation affects the overall performance of SDMs and the predicted ecological niche. We built species and lineage distribution models using three different presence‐only algorithms. We also tested for niche overlap, niche equivalency and niche similarity, using an ordination technique. We found differences in the predicted potential distribution of the two lineages and the underlying environmental factors. Moreover, intraspecific differences in model predictive capacity existed irrespective of which algorithm was used to build the distribution models. This was coupled with lineages showing a low degree of niche overlap and occurring in relatively different environmental niches spaces. The intraspecific variation observed in L. boscai led to an improved intraspecific predictivity of the lineage level based-distribution models. There was partial spatial agreement between the niche overlap and independently reported secondary contact zones. Thus SDMs built only at the species level may be too naive to predict impacts of global change on species distributions. [ABSTRACT FROM AUTHOR]

• Spider and springtail assemblages are diverse in the MSS of Sierra de Guadarrama NP. • Cold temperatures and surface habitat significantly enhance biodiversity patterns. • The size effect was different between taxa assemblages. • MSS plays a fundamental role as a faunal climate refuge in high mountain areas. The determinants of biodiversity patterns in the subterranean habitat called Mesovoid Shallow Substratum (MSS) are not well-understood. In this study, thirty-three scree slopes at high altitudes were selected across the Sierra de Guadarrama National Park in central Spain to investigate the effect of ten environmental variables on the abundance and species diversity of the spider and springtail assemblages from the colluvial MSS. In each locality, a multiperforated PVC tube with a pitfall trap inside was buried up to 1 m deep, and generalized linear models and Mantel tests were used to analyze the effect of mainly climate- and habitat-related variables on the diversity patterns of both taxa. A total of 1143 individual spiders belonging to 54 species and 40 811 springtail individuals belonging to 62 species were collected. The analyses indicated that cold temperatures and the presence of forest cover on the surface significantly enhance richness and abundance in the two taxa. Environmental similarity also had a small positive effect on faunistic similarity. However, the effects of temperature and habitat detected on spider richness and abundance were stronger than on springtails, whereas the reverse was found regarding faunistic similarity. These results indicate that subterranean dwellers respond differently to the same environmental factors, which in turn, points to a different degree of affinity for the MSS. The MSS plays an important role in the survival of high mountain arthropod species, acting as a climate refuge, so the protection of this habitat should be prioritized. [ABSTRACT FROM AUTHOR]

• In species distribution modelling, the sample size of the testing dataset is crucial. • Thirty is the minimum sample size recommended. • Sensitivity of the point of equivalency and AUC show similar bias and precision. The effect of the training dataset sample size has been shown to have profound outcomes on the performance of species distribution models. However, the effects that the testing dataset sample size can have on the assessment of a models predictive capacity has received little attention. In this study, I used simulations to study how accurate two discrimination statics, the AUC (the area under the receiver operating characteristic – ROC – curve) and Se* (the probability of correctly classifying any case and calculated from the threshold that makes minimum the difference between sensitivity and specificity), are estimated based on sample size. ROC curves with known discrimination ability were simulated, samples were randomly taken, the two discrimination statistics were estimated, and the differences between the two estimators and their respective true values were computed to understand how bias and precision were affected by sample size. In general, as sample size increases, the difference between reported and true discrimination capacity decreased. There were no important differences between the estimated AUC and Se* statistics in terms of bias and precision. Under realistic scenarios where the ROC points are not necessarily part of the true underlying ROC curve, the two discrimination statistics are both unbiased and equally precise, and the higher the true discrimination capacity is, the more accurate they are estimated. Between 20 and 30 is a lowest sample size limit since below this interval accuracy estimates considerably decreases. All together, these results are very important since many interesting SDM applications involve rare and poorly known species for which sample sizes are unavoidably small. [ABSTRACT FROM AUTHOR]

Abstract Food fraud encompasses economic fraud and can produce health problems for consumers, as well as conservation problems for the involved species. Nevertheless, few studies tested for mislabeling in restaurants. In this study, we tested for mislabeling of fish species in restaurants. We sampled 77 fish dishes from 53 different restaurants located in 9 different districts of Madrid, Spain. A short fragment of the 16S rDNA was employed for DNA amplification leading to species or genera identification. Results showed that 7 species or genera and almost 30% of the samples were mislabeled. Mislabeling was present in 37% of the sampled restaurants and in 71% of the sampled districts. Mislabeling was common and it was not correlated with a districts' economic status (i.e. with the official average square-meter price of apartments). The analyses also showed that some species were more prone to be mislabeled than others. Highlights • Fish mislabeling was tested in 77 samples from 53 restaurants of Madrid. • Mislabeling was found in 28% of the samples (44% of menu labels). • Some species were more prone to be mislabeled than others. • Mislabeling was present in 37% of the restaurants and 71% of the districts. • Mislabeling was not correlated with economic status of districts. [ABSTRACT FROM AUTHOR]