Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Jocelyn Curtis-Quick, Dan Lazell, Abi Powell, Iwan, Pippa Mansell, Laura Sheard, Conservation Society of Pohnpei, and Brian Lynch and students from the College of Micronesia for assistance in the field. Mike Cavazos, Tim Harlow, Andrew Layman, and Elizabeth Hinkle assisted with lab work. Ryan Chabarria and Sharon Furiness assisted with lab work and contributed helpful discussion. We thank David Greenfield for assisting with identifications of some species and he and Rick Winterbottom for providing preliminary dichotomous keys for Eviota species. We gratefully acknowledge the support of the staff at the Hoga Marine Research Center, Universitas Hasanuddin (UNHAS), the Wakatobi Government, the Tamana National Wakatobi, the State Ministry of Research and Technology (RISTEK), the KAUST Coastal and Marine Resources Core Lab, and the staff of the Berkley Gump Station in Moorea. Barbara Brown at AMNH, Dave Catania at CAS, and Renny Kurnia Hadiaty at MZB provided assistance with depositing voucher specimens. The first and second authors are indebted to E.V. Ohta and her family members for their selfless contributions that made this project possible. Funding for field work was provided by Operation Wallacea, and by NSF OISE-0553910 to FP.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Molecular Biology