Publications by authors named "Volcan M"

This study examines the effects of Roundup Transorb® (RDT) exposure on reproductive functions and ovarian miRNA expression in Austrolebias charrua. Exposure to RDT (at 0.065 or 5 mg.

View Article and Find Full Text PDF

Roundup Transorb (RDT) is the most popular glyphosate-based herbicide (GHB) used in agriculture, and its impact extends to non-target organisms. The annual killifish Austrolebias charrua is an endangered species endemic to southern South America and inhabits temporary ponds. This study evaluates the effects of RDT concentrations (0.

View Article and Find Full Text PDF
Article Synopsis
  • The annual killifish Austrolebias charrua is an endangered species in South America, threatened mainly by agricultural practices and the use of glyphosate-based herbicides.
  • This study focused on identifying and validating potential reference genes for qPCR normalization across different tissues, genders, and environmental conditions in A. charrua.
  • The findings revealed that the gene 18 s was the most stable reference gene, enhancing the accuracy of gene expression studies that could help in environmental monitoring of this endangered species.
View Article and Find Full Text PDF

This study aimed to analyze the toxic effects of Roundup Transorb® on the endangered Neotropical annual killifish Austrolebias charrua through the assessment of molecular and biochemical biomarkers. The fish were collected in temporary ponds and exposed to environmentally realistic concentrations of the herbicide (5 mg.L for 96 h).

View Article and Find Full Text PDF

Annual fish live exclusively in temporary wetlands and are among the shortest-lived vertebrates in the world. These fish persist in these habitats due to drought-resistant eggs, that which, through diapauses are able to detect stimuli from the environment to start the development processes. They are also able to direct their embryonic development in different trajectories with different development times.

View Article and Find Full Text PDF

The Austrolebias adloffi species group encompasses a diverse lineage of annual killifishes that occurs along the Laguna dos Patos/Lagoa Mirim system, in both Brazilian and Uruguayan territories. We herein employ an integrative taxonomy approach to describe two new species of the group, inferring their phylogenetic relationships and evaluating their conservation status. Austrolebias cheffei sp.

View Article and Find Full Text PDF

Two new species of Austrolebias are described based on specimens collected from temporary pools located in natural grassland landscape within the Araucaria Forest domain at exceptionally high altitudes (~1000 meters a.s.l.

View Article and Find Full Text PDF

World food production is directly related to human population growth. Chemicals are constantly applied to pest control in crops to increase productivity. Therefore, sustainable alternatives are needed to reduce environmental impacts.

View Article and Find Full Text PDF

A new species of Austrolebias belonging to the A. bellottii species group is herein described from the Brazilian Chaco, Mato Grosso do Sul state, constituting the northernmost record of the genus in Brazil, as well as the first record of this genus on the left bank of the Rio Paraguai. The new species is distinguished from all other species of the A.

View Article and Find Full Text PDF

Samples of Austrolebias nigrofasciatus (n = 103), an endangered species of annual fish endemic to a small area of the Patos-Mirim lagoon system encompassing the São Gonçalo Channel lowlands, were collected from eight isolated temporary ponds, four located at the known distribution range of the species and four located along the Piratini River lowlands, where morphologically different individuals were found. In the laboratory, fragments of the mitochondrial cytochrome c oxidase I (coI), cytochrome b (cytb) and nuclear rhodopsin (rho) genes were amplified, purified and sequenced for 100, 99 and 58 of these individuals, respectively. Samples were further analysed using phylogenetic and phylogeographic methods to evaluate the patterns of genetic diversity and differentiation presented within and between populations, while assessing their evolutionary history, in order to guide the application of further conservation strategies.

View Article and Find Full Text PDF

A new species of Austrolebias is described from the middle course of the Rio Camaquã, Laguna dos Patos system, Rio Grande do Sul, Brazil. The new species belongs to the Austrolebias alexandri species group, which is distinguished from the remaining congeners by the presence of a dark gray pectoral fin with bright blue iridescence in males. The new species is distinguished from all remaining species of the A.

View Article and Find Full Text PDF

To analyse the survival, pathway and time of embryo development in the annual fish Austrolebias nigrofasciatus eggs were monitored in four liquid media and two damp media under experimental conditions for 130 days until their development was complete. Eggs kept in the same breeding water from oviposition remained in diapause I (DI) during all experiments. In constrast, up to the stage prior to entering diapause II (DII), the other media had no influence on development.

View Article and Find Full Text PDF

Austrolebias Costa is a genus of annual fish inhabiting temporary wetlands in the Chaco-Pampasic region of southern Brazil, Uruguay, Paraguay, Bolivia and Argentina (Costa, 2006, Nielsen & Pillet, 2015, Alonso et al., 2016). Currently, about 45 species of Austrolebias are known (Costa, 2006, Volcan et al.

View Article and Find Full Text PDF

Two new species of the genus Melanorivulus are herein described from the middle Rio Verde drainage, upper Rio Paraná basin, Mato Grosso do Sul, Brazil. Both new species are members of the Melanorivulus pictus clade, diagnosed by having ventral process of angulo-articular vestigial and flanks intense greenish blue or greenish golden to purplish blue above anal fin base in males. Melanorivulus nigropunctatus, new species, from wetlands of a small drainage tributary of right side of the Rio Verde, differs from all other congeners by possessing black dots over the head and body in both sexes and pectoral fin orange with a dark grey margin in males.

View Article and Find Full Text PDF