Ragnhildur Guðmundsdóttir

Nationality: Icelandic
Partner Institute: University of Iceland
Start and end of PhD project: 2013-2018
e-mail: rag41@hi.is
Supervisors: Snæbjörn Pálsson, Bjarni K. Kristjánsson and Viggó Þ. Marteinsson

PhD title: Microorganisms associated with the groundwater amphipod Crangonyx islandicus

Description of research project:
Two subterranean freshwater amphipod species have been discovered in Iceland, Crymostygious thingvallensis (Kristjánsson & Svavarsson, 2004) and Crangonyx islandicus (Svavarsson & Kristjansson, 2006). These species are found within the volcanic active zone in groundwater springs. Genetic patterns within C. islandicus show different monophyletic groups in different geographic areas which indicates that the group has survived repeated glaciations in Iceland (Kornobis et al., 2010). The genetic pattern points to distinct groundwater systems within Iceland which might be characterized by distinct microbial fauna as well. Little is known of this groundwater ecosystem and nothing is known about its other species apart from our recent findings of ciliate epibionts on C. islandicus from two orders, Apostomatida and Philasterida (Gudmundsdottir et al. in press), nor the food source of the amphipods.

To explore this system further we study the microbial community in in the groundwater, the hyporheic zone and in the amphipods by targeting 16S and 18S RNA using the Illumina MiSeq high throughput sequencing technic (Degnan & Ochman, 2012). The focus has been set to the possible food source and symbiotic organism of the amphipods and variation of the microbial community in groundwater springs.

Degnan, P. H. and Ochman, H. 2012. Illumina-based analysis of microbial community diversity. ISME J 6: 183-194

Gudmundsdottir, R., Kornobis, E., Kristjánsson, B. K. & Pálsson, S. 2017. Genetic analysis of ciliates living on the groundwater amphipod Crangonyx islandicus (Amphipoda: Crangonyctidae). Acta Zoologica. In Press.

Kornobis, E., Pálsson, S., Kristjánsson, B. K. and Svavarsson, J. 2010. Molecular evidence of the survival of subterranean amphipods (Arthropoda) during Ice Age underneath glaciers in Iceland. Molecular Ecology 19: 2516-2530.

Kristjánsson, B. K. and Svavarsson, J. 2004. Crymostygidae, a new family of subterranean freshwater gammaridean amphipods (Crustacea) recorded from subarctic Europe. Journal of Natural History 38: 1881-1894.

Svavarsson, J. and Kristjánsson, B. K. 2006. Crangonyx islandicus sp nov., a subterranean freshwater amphipod (Crustacea, Amphipoda, Crangonyctidae) from springs in lava fields in Iceland. Zootaxa: 1-17.