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DNA barcoding is a powerful and widespread method used to identify large numbers of species collected in the framework of sampling activities in the field. With the exception of research projects that may count on large teams characterized by tasks' delegation and where many activities may run in parallel, in the majority of cases the barcoding effort is handled by a limited number of persons. The guidelines here reported focus on this second case, with a special attention paid to field procedures, whose efficiency and smoothness are often overlooked.

The Antarctic marine environment hosts diversified and highly endemic benthos owing to its unique geologic and climatic history. Current warming trends have increased the urgency of understanding Antarctic species history to predict how environmental changes will impact ecosystem functioning. Antarctic benthic lineages have traditionally been examined under three hypotheses: (1) high endemism and local radiation, (2) emergence of deep-sea taxa through thermohaline circulation, and (3) species migrations across the Polar Front. In this study, we investigated which hypotheses best describe benthic invertebrate origins by examining Antarctic scale worms (Polynoidae). We amassed 691 polynoid sequences from the Southern Ocean and neighboring areas: the Kerguelen and Tierra del Fuego (South America) archipelagos, the Indian Ocean, and waters around New Zealand. We performed phylogenetic reconstructions to identify lineages across geographic regions, aided by mitochondrial markers cytochrome c oxidase subunit I (Cox1) and 16S ribosomal RNA (16S). Additionally, we produced haplotype networks at the species scale to examine genetic diversity, biogeographic separations, and past demography. The Cox1 dataset provided the most illuminating insights into the evolution of polynoids, with a total of 36 lineages identified.

In most marine gastropods, the duration of the larval phase is a key feature, strongly influencing species distribution and persistence. Antarctic lineages, in agreement with Thorson's rule, generally show a short pelagic developmental phase (or lack it completely), with very few exceptions. Among them is the ascidian-feeding gastropod family Velutinidae, a quite understudied group. Based on a multilocus (COI, 16S, 28S and ITS2) dataset for 182 specimens collected in Antarctica and other regions worldwide, we investigated the actual Antarctic velutinid diversity, inferred their larval development, tested species genetic connectivity and produced a first phylogenetic framework of the family. We identified 15 Antarctic Molecular Operational Taxonomic Units (MOTUs), some of which represented undescribed species, which show two different types of larval shell, indicating different duration of the Pelagic Larval Phase (PLD). Antarctic velutinids stand as an independent lineage, sister to the rest of the family, with extensive hidden diversity likely produced by rapid radiation. Our phylogenetic framework indicates that this Antarctic flock underwent repeated events of pelagic phase shortening, in agreement with Thorson's rule, yielding species with restricted geographic ranges.

This new dataset presents occurrence data for Porifera collected in the Ross Sea, mainly in the Terra Nova Bay area, and curated at the Italian National Antarctic Museum (MNA, section of Genoa). Specimens were collected in 331 different sampling stations at depths ranging from 17 to 1,100 meters in the framework of 17 different Italian Antarctic expeditions funded by the Italian National Antarctic Research Program (PNRA). A total of 807 specimens, belonging to 144 morphospecies (i.e., 95 taxa identified at species level and 49 classified at least at the genus level) is included in the dataset. Nearly half (45%) of the species reported here correspond to species already known for Terra Nova Bay. Out of the remaining 55% previously unknown records, under a third (~29%) were classified at the species level, while over a quarter (~26%) were ascribed to the genus level only and these would require further study. All vouchers are permanently curated at the MNA and are available for study to the scientific community. A 3D model of an uncommon species from the Ross Sea, i.e. Tethyopsisbrondstedi (Burton, 1929), is also presented and will be made available for outreach purposes.

Lepidepecreella debroyeri n. sp. (Amphipoda, Lysianassoidea) is described from specimens collected at Terra Nova Bay (Ross Sea, Antarctica) in the framework of several scientific expeditions of the Italian National Antarctic Research Program. This amphipod is an obligate parasite of the regular sea urchin Sterechinus neumayeri (Meissner, 1900) and also occurs at diving depths. L. debroyeri n. sp. shares with Lepidepecreella andeep Berge, Vader & Lockhart, 2004, an abyssal species described for the Weddell Sea, an almost identical morphology and ecological traits, being both associated with sea urchins of two different families. This close relationship could be the result of a host-shift phenomenon that occurred during the high number of glacial cycles, possibly rendering the preferred host unavailable. L. debroyeri n. sp. shows a high degree of variation in terms of sex ratio and population structure between different host specimens, a fact that could be related to a great mobility of this small parasitic amphipod. The new amphipod species is itself the subject of a hyperparasitic interaction, carrying tantulocarid crustaceans on the pleopods. This represents the first record of a symbiotic interaction between a tantulocarid and an amphipod for the Southern Ocean.

In polar areas, where benthic sampling is constrained by a series of limitations imposed by climate and logistic challenges, knowledge about the key elements required to plan a successful survey is fundamental. During the International Polar Year (IPY, 2007/2008), under the Census of Antarctic Marine Life (CAML), new sampling campaigns were undertaken in several Antarctic areas comprising the Ross Sea. In this region, the 2008 NIWA IPY-CAML voyage obtained benthos samples from shelf to abyssal depths. In the present study, we focus on the Mollusca from this expedition and on the possible variations in their richness and composition with latitude and depth. Given the use of sampling gears selective for different size fractions of the macrofauna, we also assess which size fraction contained the highest biodiversity. Differences were detected in species composition with latitude (averaged across depth groups) but not for depth (averaged across latitudinal groups). Richness varied locally and showed a variety of patterns depending on the areas and depths considered. The greatest diversity of molluscs was found in the fine fraction (i.e.

The distributional records of Ophiuroidea stored at the Italian National Antarctic Museum (MNA, Section of Genoa) are presented, corresponding to 1595 individuals that belong to 35 species and 17 genera. Specimens were collected in 106 different sampling stations at depths ranging from 21 to 1652 m in the framework of 14 Antarctic expeditions to the Ross Sea, one to the Antarctic Peninsula, and one to the Falkland Islands (Islas Malvinas). Three species, Amphiura joubini Koehler, 1912, Amphiura (Amphiura) angularis Lyman, 1879, and Ophiura flexibilis (Koehler, 1911), are reported as new records for the Terra Nova Bay area, whose check-list of species increases from 15 to 18 species. The determination of these three new records was based both on morphological identification and molecular analyses (COI barcoding). Some of the genetically characterised specimens were also documented through photogrammetry and micro-computed tomography and represent the first bulk of 3D models that will be available through the MNA and Sketchfab websites, both for research and educational purposes.

The Latitudinal Gradient Program (2002–2011) aimed at understanding the marine and terrestrial ecosystems existing along the Victoria Land coast (Ross Sea), an area characterized by strong latitudinal clines in environmental factors. During the program’s voyage of the Italian RV “Italica” in 2004, a fine-mesh towed gear, the “Rauschert dredge”, was deployed for the first time at 18 stations in four latitudinal distinct shelf areas between ~71°S and ~74°S. The collected samples contained undescribed species and new records for the Ross Sea from a variety of different marine taxa. Here, we describe the molluscan fauna and investigate evidences for latitudinal effects on molluscan diversity, abundance and assemblage composition. No significant latitudinal trends were detected: while diversity did not vary significantly with latitude, species richness showed an apparent but non-significant decrease with increasing latitude. Beta-diversity was found to be high both within and between latitudinally distinct shelf areas. A large fraction (~20 %) of the collected molluscs corresponded to new species records for the Ross Sea or undescribed species. Rarity in Antarctic molluscan occurrences was confirmed, with singletons (i.e. species represented by only a single individual) accounting for a 22 % and uniques (i.e. species occurring in one sample only) for a 43.5 % of the total presence. Our study of the smaller macrofaunal benthic fraction showed that Antarctic marine research still has far to go to have robust reference baselines to measure possible changes in benthic communities, even in the case of the assumed well-known, well-sampled and well-studied group of Ross Sea shelf molluscs. We advocate the use of fine-mesh trawling gears for routine sampling activities in future Antarctic expeditions to assess the full marine biodiversity.

Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V “Italica” in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500µm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project “BAMBi” (PNRA 2010/A1.10).

Gutt, Julian ... et al.-- 21 pages, 6 figures, 4 tables, The Southern Ocean ecosystem at the Antarctic Peninsula has steep natural environmental gradients, e.g. in terms of water masses and ice cover, and experiences regional above global average climate change. An ecological macroepibenthic survey was conducted in three ecoregions in the north-western Weddell Sea, on the continental shelf of the Antarctic Peninsula in the Bransfield Strait and on the shelf of the South Shetland Islands in the Drake Passage, defined by their environmental envelop. The aim was to improve the so far poor knowledge of the structure of this component of the Southern Ocean ecosystem and its ecological driving forces. It can also provide a baseline to assess the impact of ongoing climate change to the benthic diversity, functioning and ecosystem services. Different intermediate-scaled topographic features such as canyon systems including the corresponding topographically defined habitats ‘bank’, ‘upper slope’, ‘slope’ and ‘canyon/deep’ were sampled. In addition, the physical and biological environmental factors such as sea-ice cover, chlorophyll-a concentration, small-scale bottom topography and water masses were analysed. Catches by Agassiz trawl showed high among-station variability in biomass of 96 higher systematic groups including ecological key taxa. Large-scale patterns separating the three ecoregions from each other could be correlated with the two environmental factors, sea-ice and depth. Attribution to habitats only poorly explained benthic composition, and small-scale bottom topography did not explain such patterns at all. The large-scale factors, sea-ice and depth, might have caused large-scale differences in pelagic benthic coupling, whilst small-scale variability, also affecting larger scales, seemed to be predominantly driven by unknown physical drivers or biological interactions, Thanks are due to the SCAR biology programme ‘Antarctic Thresholds-Ecosystem Resilience and Adaptation’(AnT-ERA) due to financial support of a post-expedition workshop held in Dijon, France, in 2014 and to the Deutsche Forschungsgemeinschaft for financial support of project JA-1063/17-1. ME was funded by the Actions thematiques du Muséum ‘Emergences’ of the Muséum national s’Histoire naturelle, Paris, France,and the Institut polaire français Paul Emile Victor (IPEV). [...] Support of cruise participation of PLG, IMB, NT by Spanish Project ECOWED (CTM2012-39350-C02-01)

The order Tanaidacea includes over 1000 species which are mainly free-living or tube-dwelling detritivores. Exspina typica Lang, 1968 represents an exception to these common life styles, having being found in the intestine and body cavity of deep sea holothuroids. The 2008 New Zealand ‘IPY-CAML Cruise’ held in the Ross Sea collected several deepwater holothuroids that were observed to carry specimens of E. typica inside their coelomic cavity. A clear interpretation of this association was hence possible. Even if E. typica shows slight adaptations to a parasitic life style, the tanaids were found to actively ‘dig’ into the host's skin, grasping tissue with their claws and producing tunnels in the body wall. It is therefore possible to clearly define this association, which is here reported from the Antarctic for the first time, as parasitism.

We describe a new association for Antarctica, involving an holothuroid host,Bathyplotes bongrainiVaney, 1914, and a parasitic polynoid polychaete,Eunoe opalinaMcIntosh, 1885, which lives on the host body. Both species have never been recorded in the study area, the Ross Sea. The ecological definition of this partnership is difficult to assess, being a mix of phoresis, protective association, parasitism and, possibly, kleptocommensalism.Eunoe opalinaemerges also as a true predator, ingesting several food items that do not belong to the diet ofBathyplotes. We compare this association with analogous examples known from shallow tropical environments as well as bathyal and abyssal depths. Given the conspicuous similarities between the deep water and high latitude examples of this kind of association, a possible common origin is hypothesized. Although the role of such a kind of parasitic relationships in Antarctic communities remains to be fully evaluated, it seems evident that, at high latitudes, where trophic levels are simplified and food webs do not have much redundancy, the impact of such a ‘multitasking’ predator-parasite asE. opalinamight be of a greater magnitude than its shallow water tropical counterpart.

Connectivity is a key factor in determining the genetic structure of marine populations, and type and duration of the larval phase strongly affect dispersal abilities of species. In Antarctica, invertebrates show a higher proportion of species with limited pelagic dispersal, and any exception to this pattern is worthy of attention. Capulidae is a family of kleptoparasitic gastropods, with two larval strategies. Most species have a peculiar planktotrophic larva, the ‘echinospira’, which enables a long pelagic dispersal; a minority of species undergo lecithotrophic development. We provide the first molecular phylogenetic framework for the family and define the Antarctic species based on molecular data. Based on this information, and on larval shell morphology, we tested the hypothesis that capulid species with high dispersal capacities via planktotrophic larvae display high genetic connectivity over long distances. Our data showed that whilst larval planktotrophy is the predominant larval strategy of the family worldwide, the vast majority of Antarctic species exhibit non-planktotrophic development. The unique exception, Capulus subcompressus, showed high genetic connectivity between the Ross Sea and Weddell Sea-Antarctic Peninsula. In all other Antarctic species, environmental constraints selected towards intracapsular metamorphosis, despite the associated limits of dispersal and finding a host.

Here we present distributional records for Tanaidacea specimens collected during several Antarctic expeditions to the Ross Sea: the Italian PNRA expeditions (“V”, 1989/1990; “XI”, 1995/1996; “XIV”, 1998/1999; “XIX”, 2003/2004; “XXV”, 2009/2010) and the New Zealand historical (New Zealand Oceanographic Institute, NZOI, 1958-1961) and recent (“TAN0402 BIOROSS” voyage, 2004 and “TAN0802 IPY-CAML Oceans Survey 20/20” voyage, 2008) expeditions. Tanaidaceans were obtained from bottom samples collected at depths ranging from 16 to 3543 m by using a variety of sampling gears. On the whole, this contribution reports distributional data for a total of 2953 individuals belonging to 33 genera and 50 species. All vouchers are permanently stored in the Italian National Antarctic Museum collection (MNA), Section of Genoa (Italy) and at the National Institute of Water and Atmospheric Research (NIWA Invertebrate Collection), Wellington (New Zealand). The tanaidaceans were collected during different Italian and New Zealand research expeditions to the Ross Sea funded by the Italian National Antarctic Research Program (PNRA) and the New Zealand Government, the Ministry for Primary Industries (formerly the Ministry of Fisheries) and the Ocean Survey 20/20 CAML Advisory Group, listed below: Italian PNRA Project 3.2.1 (Oceanography) (“V” expedition, 1989/1990, R/V “Malippo”). Italian PNRA Project 2a and 2d.2 (Ecology and Biogeochemistry of the Southern Ocean) (“XI” expedition, 1995/1996, R/V “Italica”). Italian PNRA Project 2b.3 (Ecology and Biogeochemistry of the Southern Ocean) (“XIV” expedition, 1998/1999, R/V “Malippo”). Italian PNRA Project Program 2002/8.6 (“The costal ecosystem of Victoria Land coast: distribution and structure along the latitudinal gradient”) (“XIX” expedition, 2003/2004, R/V “Italica” 2004). Italian PNRA Project 2006/08.01 (“The coastal ecosystem of Terra Nova Bay” in the Latitudinal Gradient Program (LGP)) (“XXV” expedition, 2009/2010). The Ross Sea Endeavour surveys (1958-59 and 1959-60, HMNZS “Endeavour II” and 1960–1961, “Endeavour III”) conducted by the New Zealand Oceanographic Institute (NZOI, now NIWA) – founded by the New Zealand government. New Zealand BIOROSS voyage (TAN0402, 2004, R/V “Tangaroa”) – funded by NIWA and the New Zealand Ministry of Primary Industries (formerly the Ministry of Fisheries). New Zealand IPY-CAML voyage (TAN0802, 2008, R/V “Tangaroa”) – Census of Antarctic Marine Life programme – funded by the Government of New Zealand and administered by the Ocean Survey 20/20 CAML Advisor Group (Land Information New Zealand and the Ministry of Fisheries, Antarctica New Zealand, Ministry of Foreign Affairs and Trade and NIWA). We would like to acknowledge the Italian National Antarctic Program (PNRA) for funding and logistic support of the scientific expeditions. The TAN0402 BIOROSS” voyage (2004) was undertaken by the National Institute of Water & Atmospheric Research and financed by the former New Zealand Ministry of Fisheries. The “TAN0802 IPY-CAML Oceans Survey 20/20” voyage (2008) was funded by the New Zealand Government under the New Zealand International Polar Year Census of Antarctic Marine Life Project. We gratefully acknowledge project governance provided by the Ministry of Fisheries Science Team and the Ocean Survey 20/20 CAML Advisory Group (Land Information New Zealand, Ministry for Primary Industries (Fisheries), Antarctica New Zealand, Ministry of Foreign Affairs and Trade, and National Institute of Water and Atmospheric Research).