ABSTRACTS Deep-Sea Biology Symposium 2018 Updated: 18-Sep-2018 • Symposium Page NOTE: These abstracts are should not be cited in bibliographies. SESSIONS • Advances in taxonomy and phylogeny • James J. Childress • Autecology • Mining impacts • Biodiversity and ecosystem • Natural and anthropogenic functioning disturbance • Chemosynthetic ecosystems • Pelagic systems • Connectivity and biogeography • Seamounts and canyons • Corals • Technology and observing systems • Deep-ocean stewardship • Trophic ecology • Deep-sea 'omics solely on metabarcoding approaches, where genetic diversity cannot Advances in taxonomy and always be linked to an individual and/or species. phylogenetics - TALKS TALK - Advances in taxonomy and phylogenetics - ABSTRACT 263 TUESDAY Midday • 13:30 • San Carlos Room TALK - Advances in taxonomy and phylogenetics - ABSTRACT 174 Eastern Pacific scaleworms (Polynoidae, TUESDAY Midday • 13:15 • San Carlos Room The impact of intragenomic variation on Annelida) from seeps, vents and alpha-diversity estimations in whalefalls. metabarcoding studies: A case study Gregory Rouse, Avery Hiley, Sigrid Katz, Johanna Lindgren based on 18S rRNA amplicon data from Scripps Institution of Oceanography Sampling across deep sea habitats ranging from methane seeps (Oregon, marine nematodes California, Mexico Costa Rica), whale falls (California) and hydrothermal vents (Juan de Fuca, Gulf of California, EPR, Galapagos) has resulted in a Tiago Jose Pereira, Holly Bik remarkable diversity of undescribed polynoid scaleworms. We demonstrate University of California, Riverside this via DNA sequencing and morphology with respect to the range of Although intragenomic variation has been recognized as a common already described eastern Pacific polynoids. However, a series of phenomenon amongst eukaryote taxa, its effects on diversity estimations taxonomic problems cannot be solved until specimens from their (i.e. under or over estimates) in metabarcoding studies have not been fully respective type localities are also sequenced. We highlight some resolved addressed. To avoid or reduce over estimations due to PCR and taxonomic issues, and new species, with respect to Bathykurila, sequencing errors, a number of steps including chimera detection, removal Branchipolynoe and Peinaleopolynoe. While many of the scaleworm of singletons, different clustering thresholds are often applied to datasets species show wide geographic ranges across thousands of kilometers, prior to any downstream analyses (e.g. alpha and beta diversity others were also only found at one site. While many were found at both comparisons). On the other hand, these same procedures can also remove seeps and whale fall habitats, very few were found to live across both variation caused by real intra-genomic and intra-specific diversity. In order seeps and vents. to evaluate the existence and the potential effects of intragenomic variation on diversity estimations, we explored an rRNA amplicon dataset (i.e. V1-V2 TALK - Advances in taxonomy and phylogenetics - ABSTRACT 226 regions of 18S rRNA) obtained from single marine nematode specimens collected from coastal and deep-sea sites. Prior to DNA extraction and TUESDAY Midday • 13:45 • San Carlos Room high-throughput sequencing using the Illumina MiSeq platform, nematode Bathyal slope to hadal trench: diversity specimens were morphologically identified (i.e. assigned to genus and/or and biogeography of Solenogastres putative species) using light microscopy, covering a wide range of nematode groups and thus allowing us to assess how frequent is (Mollusca) in the Northwest Pacific intragenomic variation in marine nematodes. Specifically, we evaluate different metrics per nematode specimen (e.g., number of OTUs, relative Franziska S. Bergmeier, Peter Kohnert, Angelika Brandt, abundance of each OTU, variation on the taxonomic assignment of OTUs, Katharina M. Jörger genetic divergence among OTUs, and the frequency of base changes in 1LMU Munich, Department Biology II, Systematic Zoology, Planegg-Martinsried, the stem and loop regions of the 18S rRNA) to depict common patterns Germany (e.g. low or high intragenomic variation, broadly or restricted among marine Several recent joint German-Russian research cruises investigated the nematode taxa). Finally, our findings are discussed in the context of deep-sea benthos in the Northwest Pacific with the aim to identify species delimitation, especially in biodiversity/ecological studies based biogeographic links or isolating factors between the semi-enclosed Sea of !1 of !100 Okhotsk and the open Pacific. Solenogastres are a clade of shell-less, Genetic connectivity and adaptive worm shaped molluscs and a frequent albeit not overly abundant component of the collected deep-sea fauna. Due to their inaccessibility and evolution in the squat lobsters Shinkaia complex taxonomy, Solenogastres are generally understudied and crosnieri inhabiting both hydrothermal underestimated – the latter at least in regard to their diversity, which is vent and cold seep habitats estimated to be at least ten-fold above the currently known 300 species. Many of these species are based on single findings and as a consequence vertical and horizontal distribution ranges of the group are poorly explored. Jiao Cheng, Min Hui, Zhongli Sha Institute of Oceanology, Chinese Academy of Sciences We studied approximately 150 specimens of Solenogastres, collected from Deep-sea hydrothermal vents and cold seeps are two types of extreme the bathyal slope and basin of the Sea of Okhotsk, the abyssal plain of the habitat for marine organisms. The differences between the ecosystems of Northwest Pacific, and hadal depths of the Kuril-Kamchatka Trench. We hydrothermal vents and cold seeps may facilitate the genetic heterogeneity used an integrative taxonomic approach combining multiple mitochondrial and local adaptation of the species in both environments. Here, we markers, 3D-microanatomy based on histology, and scanning electron combined restriction-site associated DNA (RAD) and comparative microscopy to delimitate different lineages and investigate their transcriptome analysis to evaluate the extent of genetic differentiation and bathymetric and biogeographic distribution ranges. In total, we discovered the pattern of selection in the dominant species, Shinkaia crosnieri Baba & more than 40 species in the region, largely new to science and by far Williams, 1998, inhabiting both environments. Using RAD technique, we exceeding the previously known solenogaster diversity in the area. identified 21,182 single nucleotide polymorphisms (SNPs) for 30 S. Solenogastres have rarely been reported from hadal depths, but we crosnieri specimens. In lined with mitochondrial DNA results, structural and discovered several lineages at 9,500 m. Overall there is a unique phylogenetic topology analyses based on SNPs showed clear genetic solenogaster fauna in each of the sampled regions with few lineages differentiation between the vent and seep populations. Local adaptation of present on both sides of the Kuril-Kamchatka Trench, which we think might populations was tested by searching for increased population divergence act as a barrier to their dispersal. This is the first comprehensive study using FST-based outlier tests, which resulted in 710 potentially locally evaluating phylogenetic relationships, population genetic patterns and selected SNPs. To obtain further insights into the driving force of distribution ranges in Solenogastres on a regional scale. It provides a divergence in S. crosnieri, we followed the method of comparative reliable barcoding library for easier identification in future faunistic surveys transcriptomic analysis to identify one-to-one orthologs. A total of 5347 and therein a first baseline for beta-biodiversity comparisons. orthologous unigene pairs was identified between vent and seep samples, among which 938 and 302 genes were found to undergo purifying and TALK - Advances in taxonomy and phylogenetics - ABSTRACT 175 positive selection, respectively. The functional enrichment results indicated TUESDAY Midday • 14:00 • San Carlos Room that these positively selected genes covered diverse functional categories, Multi-locus phylogenetic analysis of including sulfur metabolism, detoxification, anti-oxidative stress and immune defense, suggesting that abiotic and biotic stresses were Amphipoda supports monophyly of the important selective pressures in the adaptation of S. crosnieri to different pelagic suborder Hyperiidea deep-sea chemosynthetic environments. These results provide evidence for genetic divergence and adaptive differentiation of S. crosnieri inhabiting Leann M. Biancani, Karen J. Osborn, Michael P. Cummings hydrothermal vent and cold seep habitats and shed insights into the Smithsonian National Museum of Natural History & University of Maryland, adaptation process to deep-sea extreme environments in marcoorganisms. College Park Hyperiidea (Peracarida; Amphipoda) is an exclusively pelagic crustacean TALK - Advances in taxonomy and phylogenetics - ABSTRACT 321 suborder, possessing a wide range of unique adaptations to life in the dim, TUESDAY Midday • 14:30 • San Carlos Room open expanse of the oceanic midwater. The group exhibits such diversity that no common morphological synapomorphy unites the approximately New Species of Narcomedusae 350 described species. Hyperiid amphipods are defined only by their (Hydrozoa, Trachylina) Collected by pelagic existence, despite the presence of holopelagic representatives in several other amphipod