Invasion and Spreading of Drosophila nasuta (Diptera, Drosophilidae) in the Caatinga Biome, Brazil.

Biological invasions are one of the main causes of biodiversity loss, and it is essential to understand the pattern and rate of expansion of invasive species outside their native distribution. In this study, we documented the invasion of the Asian fruit fly, Drosophila nasuta Lamb, in the Caatinga, and measured its geographical distribution in this environment, which covers 11% of the Brazilian territory. We collected drosophilids in eight sites distributed in the north of the Caatinga (in the state of Ceará), in the south (in Bahia), in the east (in Pernambuco), and in the west (in Piauí), as well as in sites in the central area of the biome. Drosophila nasuta occurred in all areas and was one of the most frequently occurring species in half of the sampled sites. We observed greater abundance in areas with arboreal vegetation and a possible preference of this species for areas with higher annual rainfall in the Caatinga. Of all the biomes where D. nasuta is found in Brazil, the area occupied in the Caatinga is the largest documented to date. Our results show D. nasuta's success in invading the Caatinga and the vast area this species has colonized in this biome. The success of this invasion can be explained by the high fertility and short life cycle as well as by the ability of D. nasuta to use different trophic resources.

New data on Beurlenia araripensis Martins-Neto & Mezzalira, 1991, a lacustrine shrimp from Crato Formation, and its morphological variations based on the shape and the number of rostral spines.

Fossil freshwater carideans are very rare worldwide. Here, we present new taxonomic remarks about Beurlenia araripensis from the Early Cretaceous laminated limestones of the Crato Formation, Araripe Basin, northeastern Brazil. We analyzed five fossil samples, testing the morphological variations such as, rostrum with 5 to 14 supra-rostral spines and 2 to 3 sub-rostral spines, which appears as serrate for Caridea. This variation demonstrates a morphologic plasticity also seen in extant species of the group, such as those of the genera Macrobrachium and Palaemon.