The embryonic development of Piapara, Leporinus elongatus (Pisces, Anostomidae), using histological techniques, electron microscopy and immunological techniques using bone markers

The embryonic development of fishes has great importance in fish culture and on reintroduction of species at risk of extinction into their environment; its knowledge constitutes an important way to minimize diseases and mortality of these species. By using techniques like electron microscopy and immunohistochemistry for bone markers identification, it was possible to evaluate the developmental stages of Leporinus elongatus in more details, helping to clarify the habits and biology of this species. Results showed the ontogeny and ostheogenesis of of Leporinus elongatus this species from fecundation to juvenile, evidencing important structures as size of the yolk, essential to embryo nutrition, the blastopores closure, important event in embryogenesis because it indicates fertilization indexes, and the metamorphosis, which shows the main organs' development including bones. Bone morphogenetic markers 1 and 4, essential regulatory molecules for bone development, had their expression restricted from larva to fry stages, and were not observed in their previous stages. In sum, these results provided new data that may improve reproductive techniques for L. elongatus, and will support commercial and repopulation purposes.