Management of invasive populations of the freshwater crayfish Procambarus clarkii (Decapoda, Cambaridae): test of a population-control method and proposal of a standard monitoring approach.

Invasive species are one of the main threats to biodiversity. When an alien species is introduced into a new environment, fast identification and definition of management strategies may avoid or minimize impacts. When an invasive species is already established, the most adopted approaches are population control and monitoring. In order to perform such strategies, assessment of characteristics of the invasive population is imperative. This study tested a new method of population size estimation and monitoring in an invasive population of crayfish Procambarus clarkii in a conservation area in the Atlantic Rain Forest (Southeastern Brazil). The population dynamics was studied for 1 year to examine the efficacy of the selected method and to evaluate if the population is stable. Later, the effect of periodical removal of animals on the population size was tested. The method of population estimation used in this study proved to be very effective. We recommend using it to monitor invasive populations of P. clarkii. The population size varied discretely over the year with variable but low growth rate, indicating that the population is already established which introduce a notable threat to native species. The continuous removal of specimens proved to be inefficient since the growth rate was higher after the removal. One intensive removal event might be more effective than a continuous moderate removal as the one applied in this study.

Phylogenetic and environmental components of inter-specific variability in the antioxidant defense system in freshwater anomurans Aegla (Crustacea, Decapoda).

The antioxidant defense system (ADS) protects organisms against the potential oxidative stress induced by environmental features, underlying processes of habitat diversification. The anomurans Aegla constitute the most threatened freshwater decapods of South America, occupying pristine habitats with narrow distribution. Using phylogenetic comparative methods, we addressed: Is the variability of habitat physicochemical parameters and tissue ADS phylogenetically structured? How do environmental features correlate with ADS? How do they vary among species? Several physicochemical parameters of water, as well as metals in sediments, were measured in ten aeglid species' habitats. Additionally, metal accumulation and ADS parameters [metallothionein-like proteins (MTLP), antioxidant capacity against peroxyl radicals (ACAP), and glutathione system (GSH-GSSG)] were evaluated in hepatopancreas. Water conductivity and pH showed phylogenetic signal, while all other physicochemical traits demonstrated plastic variability. Metals were present at natural concentrations, which are corroborated by the relative stable GSH/GSSG ratio, and by their absence of correlation with bioaccumulation levels and MTLP, both phylogenetically structured. However, metal variability across species' niches is associated with ACAP, a potential biomarker tool. Thus, the physiological sensitivity of aeglids is environmentally driven but also  phylogenetically constrained, unraveling the importance of systematic framework for cross-species investigations and future monitoring strategies of these conspicuous freshwater animals.

Morphological and molecular data reveal the cryptic diversity among populations of Aegla paulensis (Decapoda, Anomura, Aeglidae), with descriptions of four new species and comments on dispersal routes and conservation status.

The taxonomy of the Brazilian aeglid species Aegla paulensis Schmitt, 1942 from two disjunct hydrographic basins is revised using morphological and molecular data. Results show that six disjunctive populations of Aegla paulensis form a species complex. Aegla paulensis sensu stricto is redescribed and Aegla rosanae Campos Jr., 1998 is revalidated. The four remaining populations previously assigned to Aegla paulensis are now recognized as different species, namely Aegla  vanini n. sp., Aegla japi n. sp., Aegla jaragua n. sp. and Aegla jundiai n. sp. All new species are described and illustrated and are well supported by both morphological and molecular data. Aegla lancinhas Bond-Buckup & Buckup in Santos et al., 2015, which until recently was confounded with Aegla paulensis s. str., is supported as a valid species. A key to all members of the A. paulensis species complex is provided, and their phylogenetic and biogeographic relationships to other closely related species is discussed.

Description of the newly-hatched juvenile of Aegla paulensis (Decapoda, Anomura, Aeglidae).

The postembryonic development of Aegla paulensis is epimorphic (= direct), in which the hatching form is a juvenile that morphologically resembles the adult. Hatching is asynchronous, taking 3-5 days for all juveniles from a single brood to hatch. This paper provides a complete description of the external morphology of the newly-hatched juvenile of A. paulensis as analyzed through light microscopy (LM) and scanning electron microscopy (SEM). One of the striking features ob- served in the newly-hatched juvenile of A. paulensis was the presence of four pairs of rudimentary pleopods, a trait never described before in early juveniles of Aegla. Additional novelties include three unique types of setae and two types of pore sensilla.