Dispersal of coral reef fish: Post-settlement selection processes shape the population genetic structure

• Antragstellerin: Professorin Dr. Gabriele Gerlach
• Fachliche Zuordnung: Evolution, Anthropologie
• Förderung: Förderung von 2009 bis 2014
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 125398870

This study aims to understand post-settlement factors that influence recruitment and survival of fish larvae in coral reefs. Most marine organisms show a dual life history where settled adults produce dispersing larvae. Recent research has demonstrated that larval dispersal does not necessarily result in wide distribution and genetic homogeneity as previously assumed. In the cardinalfish (O. doederleini), we found genetic isolation of reef populations at a scale of 5 to 25 km. We also found that larvae differentiate between the odor of foreign and natal reef waters, a mechanism that may contribute to natal homing by directing orientation. However, while the genetic structure was stabile over 3 years (2003-2005), genetic differences temporarily disappeared in 2006 and then re-emerged in 2007 in its original structure. This fast change in the genetic structure suggests that not genetic drift but selection processes working on specific genotypes at different reefs. In this project we will focus on analyzing such post-settlement selection processes that influence differential survival of specific genotypes of O. doederleini. Specifically we will 1) determine the genetic structure of pre- and post-settlement larvae as well as subadults and adults at different reefs using neutral markers and those under selection, and genetically assign larvae to different reef populations, and 2) conduct behavioral experiments to analyze differential survival of genotypes of settlers. The project is part of an international collaboration to answer key questions of marine larval dispersal and connectivity.

• DFG-Verfahren: Sachbeihilfen