The rainbow trout is affecting the occupancy of native amphibians in Patagonia

In this work, we assessed the occupancy of two native amphibian species of the Valcheta stream in the Somuncura Plateau, northern Patagonia: the Valcheta frog, Pleurodema somuncurense and the Argentine common toad, Rhinella arenarum. We hypothesized that the occupancy of both amphibian species will be shaped by the presence of trout; we also expected a decline in occupancy assuming that the new predator in the system will affect native amphibian populations. Between December 2014 and March 2015, we conducted surveys in 148 sites along the headwaters of Valcheta stream. We modelled the occupancy by including the presence of trout, the temperature of water and the coverage of rocks and vegetation as site-habitat covariates. Models including trout were among the best ranked for both amphibian species. The presence of trout reduced the occupancy of both species and the magnitude of this reduction was much higher in the Valcheta frog than in the Argentine common toad. Overall, our results are of great relevance for land managers considering that the Valcheta frog is among the only three IUCN Critically Endangered amphibians in Argentina.Facultad de Ciencias Naturales y Muse

Effect of Mycobacterium cell wall fraction on endometrial histomorphometry of mares resistant and susceptible to persistent breeding-induced endometritis

Mycobacterium cell wall fraction (MCWF) is a biological component made up of molecules with immunostimulant properties, which is therapeutically used to modulate persistent breeding-induced endometritis (PBIE). The aim of this study was to analyze the effect of this immunomodulator on the endometrial histological structure during the diestrus of PBIE-resistant and -susceptible mares that either received treatment with MCWF or not. The experiment was conducted with 10 resistant mares (RM) and 9 susceptible mares (SM). In the first estrous cycle of the trial, all mares were inseminated with dead semen as an inflammatory stimulus (Group A); at the next cycle, all mares were inseminated with dead semen and treated with a MCWF commercial immunomodulator (Group B). In both groups, endometrial biopsies were taken on day 7 post-ovulation (diestrus). Endometrial biopsies of untreatedRM (UTRM, n ¼ 6), untreated-SM (UTSM, n ¼ 7) MCWF-treated-RM (TRM, n ¼ 6) and MCWF-treated-SM (TSM, n ¼ 6) were evaluated. They were randomly chosen as representative mares of Group A and B, respectively. The height of lining and glandular epithelia, glandular diameter, glandular density and glandular area were evaluated. The histological structure revealed lymphocytic infiltration and dilated, tortuous glands with some glandular nests, particularly in UTSM. The histomorphometrical results showed no differences (r > 0.05) between the analyzed groups. This would indicate that post-service treatment with the MCWF immunomodulator does not modify the endometrial histoarchitecture but, apparently, its action would be mainly based on the stimulation of the cellular and humoral immune responses.Fil: Herrera, Marcela Fernanda. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otermin, Martina. Instituto Superior de Formación Docente N º10; ArgentinaFil: Herrera, Juan Manuel. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Simoy, M. Verónica. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto Multidisciplinario de Ecosistemas y Desarrollo Sustentable; ArgentinaFil: Bianchi, Carolina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Laboratorio de Endocrinología; ArgentinaFil: Aguilar, J. Javier. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Fumuso, Elida Ana. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin