Pisces, Perciformes, Eleotridae, <i>Dormitator maculatus</i> (Bloch, 1792): Distribution extension for Patos-Mirim lagoon system, state of Rio Grande do Sul, Brazil.

We present here the record of Dormitator maculatus (Bloch, 1792) to the Patos-Mirim lagoon system, RioGrande do Sul, Brazil. This is also the southernmost occurrence in South America, extending species range ca. 150 km fromthe previously known localities

A preliminary approach to embryonic development of Austrolebias wolterstorffi, an endangered neotropical annual fish species

Abstract 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. Our objective in this paper was to describe the different stages of embryonic development of Austrolebias wolterstorffi, a critically endangered annual fish. A total of 27 stages of embryonic development were identified for the two observed developmental pathways (direct and diapause 2). Of these 27 developmental stages observed, 24 were identical between the two types of trajectories and three different. A total of 90% of the embryos that completed their development proceeded normally, without pauses. One embryo had a different development from the others, entering diapause 2, with a pause in development for 48 h. Although the embryonic development of A. wolterstorffi is similar to that of other Neotropical annual fish species, the diapause 2 occurs when the embryo has a large body size and a well-developed brain, indicating that the lack of embryonic information of the genus Austrolebias may hide characteristics still undescribed or even different survival strategies than what has been observed for other annual fish

Pisces, Cyprinodontiformes, Rivulidae, <i>Austrolebias vazferreirai</i> (Berkenkamp, Etzel, Reichert and Salvia, 1994): New species record from Brazil.

The present note records for the first time the annual fish Austrolebias vazferreirai (Berkenkamp, Etzel, Reichertand Salvia) from state of Rio Grande do Sul, southern Brazil

Pisces, Cyprinodontiformes, Rivulidae,<i>Austrolebias periodicus</i> (Costa, 1999): Distribution extension in state of Rio Grande do Sul, southern Brazil

The present note extends the distribution of annual killifish Austrolebias periodicus, a endangered species,endemic of the Pampas region, in Ibicuí River basin, state of Rio Grande do Sul, southern Brazil. This information is neededto develop conservation strategies for this species and its habitat, which are at high risk due to the expansion of riceproduction and exotic forests in southern Brazil