Diversity and biogeography of southern ocean peracarid crustaceans in a changing environment

• Main Author: Di Franco, Davide
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2022
• Subjects: ddc:590; Antarctic; Southern Ocean; Weddell; Weddell Sea; Antarc*; Antarctic Krill; Sea ice; South Atlantic Ocean
• Online Access: http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/71163; https://nbn-resolving.org/urn:nbn:de:hebis:30:3-711634; https://doi.org/10.21248/gups.71163; http://publikationen.ub.uni-frankfurt.de/files/71163/phdthessisDiFranco.pdf

The Southern Ocean (SO) is one of the most pristine regions of our Planet, characterised by high levels of biodiversity (5% of the global diversity) (David and Saucède 2015) and hosting a unique fauna (up to 90% of SO species are endemic) (De Broyer and Danis 2011; Chown et al. 2015). Yet, the knowledge on SO biodiversity is still far from being completed. In addition, the knowledge on the impact that changing environments have on SO species-richness is very little and for some groups, it is still totally unknown. For instance, most of studies generally focus on one single species such as Antarctic krill (Kawaguchi et al. 2011), Clio pyramidata Linnaeus, 1767 (Orr et al. 2005), Globigerina bulloides d'Orbigny, 1826 (Moy et al. 2009), or only on a high taxonomic level (e.g. phylum, class): Echinodermata, Crustacea, Mollusca, Porifera, Bryozoa, Brachiopoda, Hydrozoa, Ascidiacea, Holoturoidea (Barnes 1999; Rowden et al. 2015; Post et al. 2017; Gutt et al. 2019; Vause et al. 2019; Pineda-Metz et al. 2020). Ultimately, the influence of sea-ice coverage on benthic species diversity was totally unknown prior to this study. In light of this, the objectives of the thesis are: 1. To expand the knowledge on shelf and deep-sea peracarid assemblage structure and abundance on a small regional (Weddell Sea) and on a large regional (Atlantic sector of the SO and South Atlantic Ocean) geographic scale. 2. To assess the environmental variables driving peracarid assemblage structure and abundance from the above mentioned areas. 3. To investigate SO benthic isopod species diversity from the Atlantic sector of the SO and assess the influence of environmental variables on their species-richness and composition. 4. To describe new possible peracarid species by means of integrative taxonomy, using morphological descriptions and whole genome sequencing analyses to support the species identification. Objective outcomes: The present thesis provides new information on the abundance and assemblage structure based on 64766 peracarid ...