Diversity and genetic structure of populations of Poecilia vivipara (Cyprinodontiformes: Poecilidae) from the northern state of Rio de Janeiro

Author(s)

Carlos Henrique Tonhatti

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2017-12-11

Examining board members

Sérgio Furtado dos Reis; Maria Imaculada Zucchi; Ana Cristina Petry; Mateus Henrique dos Santos; André Victor Lucci Freitas

• Advisor: Prianda Rios Laborda; Sérgio Furtado dos Reis

Abstract

The interaction between the environment and the biology of a species influences the genetic structure of the populations of this species occurring in this environment. Thus, by decomposing the structure genetics of a species, it is possible to understand how it is influenced by the environment in that lives. In this work I try to estimate the diversity and genetic structure of populations of a tropical fish Poecilia vivipara that inhabit the northern region of the state of Rio de Janeiro to then understand the interaction between the environment and the biology of this species. The recent colonization (< 5000) of the northern region of Rio de Janeiro by the populations of Poecilia vivipara creates an environment conducive to evolutionary and ecological analysis due to the diversity the time and space scales presented by the system. The northen region of Rio de Janeiro presents the specularity of the formation of the Paraiba do Sul river as a very large number of ponds, streams and swamps providing a large variability of habitats in a small geographic space. The main objective of this thesis was to estimate the genetic variation of the populations of Poecilia vivipara in the delta of the Paraíba do Sul River and this delta. Using this information, try to infer the genetic structure of these populations and identify the possible factors responsible for structuring. For this purpose, 420 individuals were collected and characterized genetically with the use of molecular markers. We used the Control Region of mitochondrial replication and 18 microsatellite loci isolated for this work. The results demonstrate a big amount of molecular variability in both markers in practically all populations. There was a genetic structure and this structure can not be explained by the distance between populations. The alternative hypothesis accepted to explain the structure was that the history of lagoons more precisely the predominant process in pond formation. These processes were river sedimentation and marine sedimentation. In addition, other characteristics of the biology of the species could be observed as: a importance of drainage as facilitators of migration, equal dispersion among females and males and the evidence of natural selection on the microsatellite loci (AU)

• FAPESP's process: 12/16567-7 - Diversity and genetic structure of populations of Poecilia vivipara (Cyprinodontiformes: Poeciliidae) State of Rio de Janeiro
• Grantee: Carlos Henrique Tonhatti
• Support Opportunities: Scholarships in Brazil - Doctorate