How the Genus Eusirus amphipods evolved and speciated in the Antarctic

Antarctica has been subjected to different climatic changes in the past requiring the marine fauna to either
adapt to novel environmental conditions, migrate to better conditions or become extinct. Currently,
warming of Antarctica is happening at an unprecedented rate. Understanding how these organisms have
managed to survive in the past will thus allow us to predict their possible responses to future climate
changes. Here, the amphipod Genus Eusirus will be used as model organisms since these amphipods are
very diverse and knowledge on their ecology and biogeography is still very limited. In this study, molecular,
morphological and ecological data of Eusirus will be collected. Because no reference genome exists for this
group, we will use a Next generation sequencing approach to obtain the complete mitochondrial genome
(mitogenome) of these amphipods. Draft mitogenomes have been assembled and annotated from skim
sequencing for two Eusirus species. From these mitogenomes, we designed primers for long-range PCRs to
amplify the entire mitogenome in several pieces. Complete mitogenomes will allow us to estimate genetic
divergence amongst different species and check for specific temperature adaptations of mitochondrial
genes. The obtained mitogenome data will also provide better supported phylogenies for reconstructing
evolutionary history of Eusirus. In order to get a better understanding of adaptive and/or non-adaptive
processes which led to the current diversity of Eusirus amphipods, we will explore how morphological and
ecological diversity are partitioned along the resulting phylogeny, concurrently with potential changes in
lineage diversification through time.