Thesis
New insights into the phylogeography and evolutionary history of two Mediterranean clingfish genera (Teleostei, Gobiesocidae)
Wagner, M.
Record Number:
4898
Year:
2018
Abstract:
Throughout the Mediterranean Sea, the clingfish genera Lepadogaster and Gouania (Teleostei, Gobiesocidae) are found in the interstitial of pebble and boulder beaches. Even though these fishes can reach fairly high abundances, the overall knowledge about the two genera is still very poor. Hence, this thesis should provide novel insights into diversity, evolution and distribution of these two clingfish taxa.
The first part of this work addresses phylogenetic and biogeographic implications in the clingfish species Gouania willdenowi (Risso 1810), the sole representative of the monotypic genus Gouania. Endemic to the Mediterranean Sea hardly anything is known about its biology, behaviour, phylogeny or taxonomy of this species. DNA-barcoding, multi-locus species tree analysis, as well as geometric morphometrics and MicroCT imaging across a pan-Mediterranean sample, revealed unexpected results regarding evolutionary history and species diversity in this genus. Molecular data suggests that the genus underwent a thus far unrecognized Pleistocene radiation into several fairly divergent species. Moreover, whereas little diversity is seen in the western basin, convergently evolved syntopic species pairs are found throughout the eastern basin and the Adriatic Sea. Apparently, the extremely low active dispersal ability of adults implies that larval drift strongly constrains gene flow among species in different Mediterranean basins.
The second part of the thesis reports on a significant extension of the distribution range of the species Lepadogaster purpurea. A combined approach of molecular and classical morphometrics on newly collected material from the eastern Mediterranean basin showed that the geographic distribution of this fish has been underestimated in the literature. Based on already published results (Wagner et al. 2017), preliminary insights into phylogeographical structure of L. lepadogaster and L. purpurea indicate marked differences between these two species.
Institution:
Karl-Franzens Universität Graz Institut für Zoologie
Times Cited:
5