Chromosomes of the Antarctic amphipod Waldeckia obesa Chevreux

Mitotic and meiotic chromosomes of the Antarctic lysianassoid amphipod Waldeckia obesa are described. The modal chromosome number is n = 25 and 2n = 50. The potential applications of cytogenetical studies in this group are discussed.     

Systematic review of Atractus schach (Serpentes: Dipsadidae) species complex from the Guiana Shield with description of three new species

The Guiana Shield harbours one of the best preserved and largest extents of tropical forest on Earth and an immense biodiversity. The herpetofauna of this region remains poorly known. The species-rich snake genus Atractus contains ～140 species, many with complicated taxonomic histories, including A. schach. Examination of specimens in museums and newly collected material from French Guiana has allowed the illustration of hemipenial morphology for the first time and an expanded diagnosis. Concatenated molecular phylogenetic (mitochondrial and nuclear genes) and phenotypic (morphometrics, external and hemipenial morphology) analyses confirm non-monophyly of the A. flammigerus group and indicate that A. schach is a species complex with three new species described here. The geographic distribution of A. schach sensu stricto is restricted to Guiana, Surinam, and French Guiana north of Tumucumaque massif. Populations tentatively assigned to A. schach from the east from French Guiana in the Roura lowlands to Almeirim, and from central Amazonia between the Negro and Trombetas rivers in Brazil are also recognized as new species. Our results suggest that populations from south of the Amazon River are not conspecific with those from the Guiana Shield.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:A7AE40BC-4716-4302-B3BE-1F43600B0A72     

Competitive strategies between Anastrepha fraterculus and Anastrepha obliqua (Diptera: Tephritidae) regulating the use of host fruits

Interspecific competition between individuals of different species can result in reductions in their fecundity, growth or survival, reflecting differential exploitation of resources that become intensified due to spatial co-occurrence, ecological similarity and increased population densities. As two species cannot occupy the same niche, coexistence is only possible if the available resources are used in non-overlapping manners such as niche partitioning or the use of refuges. Among agricultural insect pests, such as fruit flies of the family Tephritidae, competitive interactions can result in competitive displacement, host changes, or the expansion or restriction of the numbers of hosts utilized that can have negative consequences for human agricultural activities. We evaluated the competitive interactions between two fruit fly species of the genus Anastrepha, Anastrepha obliqua (Macquart, 1835) and Anastrepha fraterculus (Wiedmann, 1830), on their respective preferred hosts (mangoes and guava). Experiments of larval competition and competition for ovipositioning sites by adult females were performed to compare the parameters of larval development time, numbers of pupae and emerged adults and numbers of ovipositions in the presence or absence of interspecific competition. We observed that the interactions between those species were asymmetrical and hierarchical, and our results suggest a competitive displacement of A. fraterculus by A. obliqua when those two species are present on the same fruit, whether mangoes or guavas.     

Evaluation of monocyte subsets and markers of activation in leprosy reactions

Understanding host immune pathways associated with tissue damage during reactions are of upmost importance to the development of immune intervention strategies. The participation of monocytes in leprosy reactions was evaluated by determining the frequency of monocyte subsets and the degree of cellular activation through the expression of MHCII and the co-stimulatory molecules CD40, CD80, CD86. Leprosy subjects with or without reactions were included in this cross-sectional study. Peripheral blood mononuclear cell were isolated and stained ex vivo to determine monocyte subsets and the degree of cellular activation by flow cytometry. Intermediate monocytes were increased in leprosy patients with reactions when compared to patients without reactions. Although no difference was detected in the frequency of monocyte subsets between type 1 and 2 reactions, the expression of CD80 was increased in monocytes from patients with type 1 reactions and CD40 was higher in paucibacillary subjects presenting type 1 reactions. Moreover, CD86 and MHC II expression were higher in intermediate monocytes when compared to the other subsets in leprosy reaction types 1 and 2. Intermediate monocyte activation with CD86 and MHCII expression is involved with both type 1 and 2 reactions, whereas CD80 and CD40 expression is related to type 1 reactions.