Understanding the role of genes and the environment in determining phenotypic variation in the genus Orthopyxis (Cnidaria, Hydrozoa) from the southwestern Atlantic Ocean

Abstract

In marine populations, realized dispersal is known to directly affect population connectivity and determine the pattern and level of genetic differentiation. Although many benthic species of hydroids have experienced loss or reduction of their planktonic stage, they appear to be capable of long-distance dispersal via rafting due to their occurrence over wide geographic ranges. In addition, phenotypic variation over the same range suggests a role for phenotypic plasticity along environmental gradients. In this project we propose to investigate the relationship between morphological, genetic and environmental variability with hydroids of the genus Orthopyxis, in order to understand the role of phenotypic plasticity in shaping patterns of phenotypic variation among marine populations. For this, mitochondrial and nuclear genetic data will be compared with morphometric and environmental data from different populations off the coast of Brazil. General and/or mixed linear models will be used to test for associations of morphological, environmental, and genetic variation. (AU)