Annual killifish adaptations to ephemeral environments: Diapause i in two austrolebias species.

Background: Many organisms are able to survive in extreme environments by entering a state of dormancy. In dormancy, vital activities are reduced until environmental conditions are compatible with active life. Annual killifishes show a special developmental pattern characterized by a phase of dispersion-reaggregation of the blastomeres that separates epiboly from organogenesis, and the capability to enter dormancy in diapause.

Sex determination in annual fishes: Searching for the master sex-determining gene in Austrolebias charrua (Cyprinodontiformes, Rivulidae).

Evolution of sex determination and differentiation in fishes involves a broad range of sex strategies (hermaphroditism, gonochorism, unisexuality, environmental and genetic sex determination). Annual fishes inhabit temporary ponds that dry out during the dry season when adults die. The embryos exhibit an atypical developmental pattern and remain buried in the bottom mud until the next rainy season.

Annual fish: developmental adaptations for an extreme environment.

Annual fish are freshwater teleosts found in South America and Africa that are exposed to an extremely variable environment. They develop and reproduce in seasonal ponds that dry during the summer eliminating the entire adult population. Remarkably, desiccation-resistant embryos survive in these dry ponds that hatch during the next rainy season when the ponds are recreated.

Gamete interactions in teleost fish: the egg envelope. Basic studies and perspectives as environmental biomonitor.

The current knowledge about teleost fish egg envelope is summarized. The paper analyzes the organization and deposition process of the protein composition and genes involved in the synthesis of teleost fish egg envelopes and their role in gamete interaction during fertilization. Pelagic and demersal species that our research group is working with are especially considered.