Evolution in Scyphozoa: integrating morphology, molecular data and biology

Abstract

Speciation processes and distributional patterns related with time and space are the focus of many research projects. Although, studies dealing with the marine fauna are scarce and for some groups/areas almost absent. Even more, approaches considering biological characters (such as life cycle) in the analysis are lacking. This project aims to estimate and, later, compare phylogeographical patterns of two families of scyphozoan jellyfishes: Pelagiidae and Nausithoidae. The patterns will be discussed considering the species life cycles searching for differences in the speciation events. For the present project 37 species belonging to 5 genera will be used. Morphological and molecular data will be obtained from polyp and medusa stages, mostly already available for the beginning of the work. The elaboration of phylogenetic hypothesis will occur combining morphological and molecular data. Later on molecular clock techniques will be employed to date cladogenesis events. These events will be correlated with geological/environmental episode that can explain the observed patterns. The main idea of the project is to answer basic questions about speciation processes and to verify if the life cycles have a key role in the distribution models of recent species. This project will result in relevant publications to many fields of knowledge, especially those related to the distribution of species, cladogenesis events and marine biology. (AU)