Banca de DEFESA: IVAN PEDRO AZEVEDO CAMPOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : IVAN PEDRO AZEVEDO CAMPOS
DATE: 27/10/2022
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/henrique-batalha-filho-2
TITLE:

Evaluating the effects of isolation time between coastal paleodrainages on the population structure of freshwater ichthyofauna in southeastern-south Brazil

KEY WORDS:

Mitochondrial DNA, Quaternary, population differentiation, genetic diversity, paleobasins

PAGES: 62
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Among several global historic events, quaternary sea level oscillations stand out due to its large impact on costal landscapes. Especially on the Brazilian coast, that has a large coast, relative low relief and extensive continental shelfs at north and south, promoting the formation of coastal paleodrainages, often used to infer sea oscillations effects on freshwater biota. In turn, coastal freshwater fishes were particularly impacted to these events as they present high geographic restriction and life habit connected to these systems, making freshwater fishes ideal biogeographic models to study these events. Nevertheless, published biogeographic studies were limited to include only the Last Glacial Maximum period and few taxa, failing in consider temporal and synchrony perspective of sea level variations. Therefore, our study objective was to evaluate how Quaternary sea level oscillations affected population genetics parameters of seven coastal freshwater fish species from southeastern Brazil. We gathered mtDNA data from biogeographic studies with coastal freshwater fishes. We also reconstructed paleobasins and paleodrainages of study area for several temporal periods with bathymetric rasters and sea level fluctuation data. From that we calculated hydrographic distance, temporal isolation, genetic divergence, area, fragmentation events and nucleotide diversity for population pairs and paleobasins for each species. The relationships between variables were tested along with Multiple Matrix Regression with Randomization (MMRR) and Generalized Linear Model (GLM) analysis. Our results support positive relationship among paleobasins area and genetic diversity but showed partial support for relationship among isolation time and genetic similarity, according to species and their aspects, like habitat, environments requirements, populational size and dispersal capacity. Overall, with an integrative approach, with mtDNA and temporal detailing for sea level effects on freshwater fishes populations and paleodrainages, we show that distinct fish species were distinct affected by a same historical event in a same region.

COMMITTEE MEMBERS:
Presidente - 2048980 - HENRIQUE BATALHA FILHO
Interno - 3062840 - BRUNO VILELA DE MORAES E SILVA
Externa à Instituição - ANDRÉA TONOLLI THOMAZ - UBC