Structural analysis of the embryonic development in Brycon cephalus (Günther, 1869)

• Grant number: 06/02038-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2006
• End date: July 31, 2007
• Field of knowledge: Biological Sciences - Zoology - Applied Zoology
• Principal Investigator: Alexandre Ninhaus Silveira
• Grantee: Juliana Sversut de Alexandre
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

The fishes's embryology is a complex phenomena that besides the ontogenetic's studies, contributes to a larger knowledge of it's reproductive biology, as well as, it aids in the improvement of the reproduction techniques in captivity. Brycon cephalus, is a type of fish belonging to the family Characidae, it is original from the Amazon Basin, it presents reproductive migratory behavior and total spawn. For this work matrinxã specimens belonging from the broodstock of CEPTA - Centro de Pesquisa e Gestão de Recursos Pesqueiros Continentais - IBAMA, Pirassununga, São Paulo, Brasil. The reproducers will be induced to the reproduction with extract of carp's hypophysis. Samples will be collected from the moment of the extrusion of the egg-cells, fertilization and embryogenesis, until the moment of the hatchery point, being the material fastened in solution of Karnovsky and glutaraldehyde 2,5%. For light microscopy, the samples will be washed in alcohol 70%, dehydrated, included in glycol-methacrylate, submit to microtomy and stained with Harries-eosine hematoxylin. For analyses under scanning electronic microscope (SEM), the embryos pre-fixed in 2.5% glutaraldehyde will be transfer to a 13mm cover slide embed with 1% poli-L-lysine, post-fixed in 0.5% osmium tetroxide, dehydrated with ethanol and dry in a critical point machine Balzers CPD-20. The samples will be cover with a 10mm gold pellicle in a Balzers Metalizer MED-010 and will observe and electromicrograph by using a scanning electronic microscope Phillips-SEM 515. This work will analyze the structure of the egg-cells during the fertilization and the morphologic events that happen during the embryogenesis of B. cephalus. (AU)