A decrease in taxonomic and functional diversity of dung beetles impacts the ecosystem function of manure removal in altered subtropical habitats.

The loss of biodiversity-caused mainly by habitat destruction-is one of the environmental problems with major repercussions on ecosystem functioning. Nevertheless, our understanding of the functional consequences of habitat changes on the communities and ecosystems remains limited to a small number of case studies. We evaluated the change in taxonomic and functional diversity of copro-necrophagous beetles (Scarabaeinae) and their relationship with the varying environmental factors present in four habitats with different degrees of disturbance. Furthermore, we evaluated how changes in taxonomic and functional diversity affect the rates of excrement removal. The collections were carried out at four locations in the state of Santa Catarina, Southern Brazil, on natural systems with different degrees of disturbances (forests in advanced and initial succession) and agroecosystems (silviculture and pastures dedicated to livestock). We collected a total of 1266 dung beetles distributed in 35 species and classified into 11 functional groups. The taxonomic and functional diversity analyses showed that habitats that still maintain an arboreal stratum do not present differences between them, in contrast to habitats dedicated to livestock where there was a significant loss of species and functional groups. The distance between the trees, as well as the air and soil temperatures were determining factors in the selection of species and functional groups. Some of these environmental factors explain the differences in functional traits, represented as varying abundances of the species found. The rates of manure removal from the ecosystem were positively correlated to taxonomic and functional richness as well as biomass of beetles. Thus, we can conclude that habitats with tree strata have the capacity to preserve a larger proportion of the regional set of species as well as the important ones, while preserving the taxonomic and functional diversity and the ecosystem functions, such as the excrement removal rate.

Taxonomic reassessment of the genus Dichotomius (Coleoptera: Scarabaeinae) through integrative taxonomy.

Dung beetles of the subfamily Scarabaeinae are widely recognised as important providers of multiple ecosystem services and are currently experiencing revisions that have improved our understanding of higher-level relationships in the subfamily. However, the study of phylogenetic relationships at the level of genus or species is still lagging behind. In this study we investigated the New World beetle genus Dichotomius, one of the richest within the New World Scarabaeinae, using the most comprehensive molecular and morphological dataset for the genus to date (in terms of number of species and individuals). Besides evaluating phylogenetic relationships, we also assessed species delimitation through a novel Bayesian approach (iBPP) that enables morphological and molecular data to be combined. Our findings support the monophyly of the genus Dichotomius but not that of the subgenera Selenocopris and Dichotomius sensu stricto (s.s). Also, our results do not support the recent synonymy of Selenocopris with Luederwaldtinia. Some species-groups within the genus were recovered, and seem associated with elevational distribution. Our species delimitation analyses were largely congruent irrespective of the set of parameters applied, but the most robust results were obtained when molecular and morphological data were combined. Although our current sampling and analyses were not powerful enough to make definite interpretations on the validity of all species evaluated, we can confidently recognise D. nisus, D. belus and D. mamillatus as valid and well differentiated species. Overall, our study provides new insights into the phylogenetic relationships and classification of dung beetles and has broad implications for their systematics and evolutionary analyses.

Gastrojejunal anastomosis using a tissue-apposing stent: a safety and feasibility study in live pigs.

BACKGROUND AND STUDY AIMS: Various techniques using surgical and natural orifice transluminal endoscopic surgery (NOTES) have been evaluated to create a gastrojejunal bypass. The aim of the current study was to determine the safety, feasibility, and efficacy of a new technique using a pure endoscopic approach and tissue-apposing stent placement for gastrojejunal anastomosis (GJA). MATERIALS AND METHODS: This was a prospective, experimental study on six live pigs weighing 20 - 45  kg. Endoscopies were performed using a double-channel gastroscope, and included the creation of a GJA using a tissue-apposing, fully covered, self-expanding metallic stent. Antibiotic therapy was continued for 7 days after the procedure, and food was gradually reintroduced from Day 3. Changes in weight following the procedure were compared with a control group of age-matched animals. Anastomosis functionality was confirmed by endoscopy at 3 weeks (before the animals were euthanized), and during histopathological analysis. The primary outcomes were morbidity and mortality at 3 weeks. Secondary outcomes were technical feasibility, procedure time, and patency of the GJA. RESULTS: The procedures were performed successfully in all animals. The mean procedure time was 26  ±  6.7 minutes (range 15 - 32 minutes). One case of stent migration occurred during the procedure; the stent was successfully replaced using the same procedure. All animals were alive after 3 weeks. The mean weight gain during follow-up was 0.85  ±  2.56  kg (range - 2 to + 2  kg) compared with 5.2  ±  1.6  kg (range 3 - 7  kg) in control animals (P = 0.007). At necropsy, the stents were still in place in all animals, without evidence of peritonitis. Histopathology confirmed permeable anastomoses with continuity of the mucosa and mucosa muscle layers. CONCLUSIONS: GJA with a tissue-apposing stent is safe, feasible, and reproducible without anastomotic leakage in a porcine model using a pure endoscopic approach and standard endoscopic equipment.