MIOGÊNESE DO TECIDO MUSCULAR BRANQUIAL DO PEIXE EURIALINO Poecilia vivipara (Cyprinodontiformes, Poeciliidae) EXPOSTO À SALINIDADE

Abstract

The teleost Poecilia vivipara are characterized as euryhaline, in other words, they modulate gill cell behavior to survive in environments with varying salinity. P.vivipara gills have a set of striated skeletal muscles, abductor and adductor muscles, which plays an important role in the respiration process. This study aimed todescribe the morphology of gill muscles during the early stages of development and perform an initial morphological characterization of adults P.vivipara. Moreover, it aimed to analyze the effects of different concentrations of salinity on the morphological characteristics of muscle fibers in fingerlings´ gills. Results showed that the muscle fibers are formed between phases 2 and 3 of embryonic development. At this stage of development, gill muscles are inserted into the basal portion of gill filament, possibly in the bulkhead of cartilage that supports the gills, and organized in musclebundles located along the gill filament. This morphological organization remains in adults. An increase in the diameter of the fibers and muscle bundles was observed in fingerlings exposed to concentrations of sea salt, which allows relating the body size of P.vivipara with the degree of salinity of the environment where theylive.

Keywords

• guppy
• gill muscle
• ontogeny
• salinity.