Morphological diversification of the endemic Antarctic fishes Trematominae (Notothenioidei, Teleostei)

Adaptive radiation involves the early, rapid ecological and morphological diversification of multiple lineages from a common ancestor into new, diverging adaptive zones. Regarding this definition with emphasis on the tempo of diversification, Antarctic notothenioids represent one of the very few examples of adaptive radiation in marine fishes. Time-calibrated phylogenies suggest that the diversification of most speciose notothenioid lineages occured between 20 and 15 Ma. The subfamily Trematominae is one of those diverse subclades showing a large range of ecological niches. In the present study, we aim to describe the evolutionary history of Trematomus species. By combining a consensus time-tree and a geometric morphometric dataset, we first illustrate their pattern of cephalic shape diversification in a phylomorphospace and we infer the morphology of their common ancestor. We also explore whether the cephalic shape data shows a phylogenetic signal, which is defined as the statistical dependence among species trait values due to their phylogenetic relatedness. The combination of phylogenetic signal test and exploration of the phylomorphospace allows us to assess whether Trematomus rapidly diverged in various adaptive zones as expected under a classic scenario of adaptive radiation.Refugia and Ecosystem Tolerance in the Southern Ocean (RECTO

The Belgica 121 expedition to the Western Antarctic Peninsula: A detailed biodiversity census

Background This dataset relates to the biodiversity census carried out during the Belgica 121 (B121) expedition to the Western Antarctic Peninsula from February to March 2019. One of the aims of the campaign was to explore the surroundings of the Gerlache Strait and to carry out a detailed biodiversity census focusing on inter- and subtidal shallow-water areas using both classic descriptive marine ecology methods, as well as state-of-the art techniques (habitat mapping, genetics, trophic ecology). The biodiversity census was carried out onboard a nimble research vessel, RV Australis. This dataset will offer access to the raw data on biodiversity occurrences, obtained using a range of methods described in this data paper. New information New raw biodiversity data for a poorly-sampled region (Western Antarctic Peninsula) with a special focus on shallow ecosystems.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Nimble vessel cruises as a complementary platform for Southern Ocean biodiversity research: concept and preliminary results from the Belgica 121 expedition

Abstract The western Antarctic Peninsula is facing rapid environmental changes and many recent publications stress the need to gain new knowledge regarding ecosystems responses to these changes. In the framework of the Belgica 121 expedition, we tested the use of a nimble vessel with a moderate environmental footprint as an approach to tackle the urgent needs of the Southern Ocean research community in terms of knowledge regarding the levels of marine biodiversity in shallow areas and the potential impacts of retreating glaciers on this biodiversity in combination with increasing tourism pressure. We discuss the strengths and drawbacks of using a 75’ (23 m) sailboat in this research framework, as well as its sampling and environmental efficiency. We propose that the scientific community considers this approach to 1) fill specific knowledge gaps and 2) improve the general coherence of the research objectives of the Antarctic scientific community in terms of biodiversity conservation and the image that such conservation conveys to the general public.info:eu-repo/semantics/publishe

Not Frozen in the Ice: large and Dynamic Rearrangements in the Mitochondrial Genomes of the Antarctic Fish

The vertebrate mitochondrial genomes generally present a typical gene order. Exceptions are uncommon and important to study the genetic mechanisms of gene order rearrangements and their consequences on phylogenetic output and mitochondrial function. Antarctic notothenioid fish carry some peculiar rearrangements of the mitochondrial gene order. In this first systematic study of 28 species, we analysed known and undescribed mitochondrial genome rearrangements for a total of eight different gene orders within the notothenioid fish. Our reconstructions suggest that transpositions, duplications and inversion of multiple genes are the most likely mechanisms of rearrangement in notothenioid mitochondrial genomes. In Trematominae, we documented an extremely rare inversion of a large genomic segment of 5300 bp that partially affected the gene compositional bias but not the phylogenetic output. The genomic region delimited by nad5 and trnF, close to the area of the Control Region, was identified as the hot spot of variation in Antarctic fish mitochondrial genomes. Analysing the sequence of several intergenic spacers and mapping the arrangements on a newly generated phylogeny showed that the entire history of the Antarctic notothenioids is characterized by multiple, relatively rapid, events of disruption of the gene order. We hypothesised that a pre-existing genomic flexibility of the ancestor of the Antarctic notothenioids may have generated a precondition for gene order rearrangement, and the pressure of purifying selection could have worked for a rapid restoration of the mitochondrial functionality and compactness after each event of rearrangement

What is APECS Belgium?

The Association of Polar Early Career Scientists (APECS) is an international and interdisciplinary organization for undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and other people with interests in Polar Regions and the wider cryosphere. Its main goals are communication, education, outreach, and assistance to early career scientists. The APECS leadership team is comprised of early career researchers that are interested in and committed to furthering the activities and the future directions of the organisation. Project initiation and management, web-based or in-person events, are carried out by a number of member-initiated working groups and committees made up of both members and mentors. APECS Belgium, the Belgian National Committee of APECS, was founded in 2011 and has organized and participated in many events and activities since; for example: Conference Symposia, Science fair, school visits, workshops, documentary screenings, outreach events and much more. APECS Belgium encourages polar research at the national level by promoting research projects and institutes in the Belgian territory and sharing the fascination of the Poles with other researchers and the community. Every early career scientist based in Belgium with an interest in the Polar Regions is highly encouraged to join us! We also invite people with links to polar education and research to become part of APECS Belgium. For more information, visit our website: www.apecsbelgium.wordpress.com