Population variability in mangroves: molecular and morphological analyses in Brachyura crabs (Crustacea: Decapoda)

Author(s)

Raquel Corrêa Buranelli

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (PCARP/BC)
• Defense date: 2016-03-18

Examining board members

Fernando Luis Medina Mantelatto; Luis Ernesto Arruda Bezerra; Antonio Leão Castilho; Maura Helena Manfrin; Evandro Marsola de Moraes

• Advisor: Fernando Luis Medina Mantelatto

Abstract

The analysis of population structure of codistributed species allows the comparison of patterns of population structuring, providing information on the factors that influence the differentiation in species belonging to the same ecosystem. This project aimed to analyze the intraspecific variability of crabs inhabiting mangroves, codistributed along the western Atlantic Ocean, by means of molecular and morphological tools, in order to test the hypothesis of high populational structure in mangroves. The genetic variability of five species used as models (Aratus pisonii, Goniopsis cruentata, Sesarma rectum, Uca thayeri and Ucides cordatus) was assessed using the mitochondrial genes COI and 16S and the nuclear H3 and comparative morphological analysis and morphometry were performed. The molecular data revealed two patterns, indicating high population structure for the species A. pisonii and U. thayeri and absence of structure for G. cruentata, S. rectum and U. cordatus. The morphological data, however, do not follow these patterns, because there were no morphological or morphometric differences associated with the groups evidenced by the molecular analyzes. Possibly the absence of gene flow between regions for some species is due to factors not limited to isolation by distance, but also because of differences in the larval stage duration and in withstanding some abiotic factors, such as salinity. These factors associated with different characteristics of larval development can culminate in differences on population structure. In addition, the genetic differentiation patterns observed agree with biogeographical scenarios proposed for the western Atlantic, where geological, climate and oceanographic fluctuations, resulting from the Isthmus of Panama closure and cyclical glaciation in North America, promoted genetic divergence. (AU)

• FAPESP's process: 12/06299-5 - Populational variability among decapod crustacean species from mangroves: morphological and molecular analysis
• Grantee: Raquel Correa Buranelli
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)