Morphological characterization of female gonadal cycle and oogenesis of porquinho Geophagus proximus (Perciformes, Cichlidae)

• Grant number: 12/00765-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2012
• Effective date (End): December 31, 2013
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Rosicleire Veríssimo Silveira
• Grantee: Laíza Maria de Jesus Silva
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

It is estimated that fish comprise about 33.00 species, both freshwater and marina, and that the neotropical freshwater fish is estimated at 8.000 species representing 24% of all species, showing forms and patterns of different life cycles. The Neotropical cichlids occupy lentic habitats within rivers and streams, but there is also a number of moderately to strongly adapted rheophilic species. The cichlid Geophagus proximus, is endemic in the Amazon Basin, Brazil and Peru, being popularly known as porquinho. Although its introduction is recent, for unknown reasons, and causes and impacts are not scaled, became the second dominant species in fisheries science and the main commercial fisheries in the reservoir of Ilha Solteira, Rio Parana. Thus, this study aims to define the ovarian reproductive classes and perform structural morphological characterization of folliculogenesis and oogenesis of the species. Adult female specimens of Geophagus proximus will be collected from March 2012 to January 2013 in the reservoir of Ilha Solteira. The gonads are removed following the procedures of fixation and inclusion, microtomy and staining the material to be analyzed by light microscopy. Therefore, the study of the reproductive cycle of female Geophagus proximus, as well as the characterization of ovarian structure is fundamental to the understanding of their reproductive adaptations and their reproductive period during the year in Ilha Solteira reservoir. (AU)