Renault D, . (2011). Sea water transport and submersion tolerance as dispersal strategies for the invasive ground beetle Merizodus soledadinus (Carabidae)
. 0722-4060, 34(10), 1591–1595.
Abstract: The alien ground beetle Merizodus soledadinus was introduced to the sub-Antarctic Kerguelen Islands in 1913. It colonized several small islands and islets of this archipelago, without any apparent human assistance in some locations, and crossed several large rivers and alluvial plains. As aggregations of this species on the tidal drift line are common at the Kerguelen Islands, the present work examined whether adult individuals of M. soledadinus could disperse by flotation on the sea. Different sample sizes of ground beetles (from 1 to 10) were placed on sea water at 8°C in plastic vials. Survival (50% lethal times) significantly increased from 2.1 ± 0.2 days for single beetles to 6.5 ± 0.3 days for groups of 10 beetles per vial, with there being no difference in the survival duration for groups of 2, 5, and 10 beetles per vial. Similar survival durations were found for beetles in vials with artificially agitated water and controls. In addition, the duration of survival was twice as high under freshwater versus sea water conditions, when groups of 10 adults were used. Finally, the survival to total submersion in freshwater was evaluated, and ranged from 3 to 4 days. This ability to survive extended periods both floating on and/or submerged beneath salt and freshwater conditions, indicates the presence of a successful dispersal mechanism, which may facilitate the dispersal range of M. soledadinus across the Kerguelen Islands, comprising over 300 islands and islets in total.
Keywords: Biomedical and Life Sciences,
Programme: 136
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Eléaume Marc, Hemery Lenaïg, Bowden David, Roux Michel, . (2011). A large new species of the genus Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae) from Antarctic seamounts
. Polar Biol., 34(9), 1385–1397.
Abstract: Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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Lecointre Guillaume, Gallut Cyril, Bonillo Céline, Couloux Arnaud, Ozouf-Costaz Catherine, Dettaï Agnès, . (2011). The Antarctic fish genus Artedidraco is paraphyletic (Teleostei, Notothenioidei, Artedidraconidae)
. Polar Biol., 34(8), 1135–1145.
Abstract: Artedidraconids (Plunderfishes) are small benthic notothenioid fishes of the Antarctic and South Georgia shelf and slope. The family Artedidraconidae is monophyletic; however, the relationships within the family have remained poorly explored until now, and based on a small sample of the genus Artedidraco . The present study focuses on the interrelationships among the artedidraconid genera and the phylogeny of the genus Artedidraco . 2,353 base pairs from 77 specimens were sequenced from the partial mitochondrial cytochrome oxidase I gene and cytochrome b gene, the partial mitochondrial control region and the partial nuclear rhodopsin retrogene. The genus Artedidraco is not monophyletic, confirming the preliminary relationships found by Derome et al. (Mol Phylogenet Evol 24:139152, 2002 ): Pogonophryne , Dolloidraco and Histiodraco are well embedded within the genus Artedidraco . From Artedidraco skottsbergi and A. loennbergi to A. orianae and A. mirus , the tree shows that there is an increasing number of upper lateral line tubular scales and decreasing number of disc-shaped scales. There is also a trend toward a decrease in the number of epipleural ribs and an increase in number of pleural ribs along the tree.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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Ledoux J-B, Tarnowska K, Gérard K, Lhuillier E, Jacquemin B, Weydmann A, Féral J-P, Chenuil A, . (2011). Fine-scale spatial genetic structure in the brooding sea urchin Abatus cordatus suggests vulnerability of the Southern Ocean marine invertebrates facing global change
. Polar Biol., , 1–13.
Abstract: The Southern Ocean benthic communities are characterized by their levels of endemism and their diversity of invertebrate brooding species. Overall, biological processes acting within these species remain poorly understood despite their importance to understand impacts of ongoing global change. We take part in filling this gap by studying the genetic structure over different spatial scales (from centimeters to tens of kilometers) in Abatus cordatus , an endemic and brooding sea urchin from the Kerguelen Islands. We developed three microsatellites and two exon-primed intron crossing markers and conducted a two-scale sampling scheme (from individuals to patches) within two dense localities of Abatus cordatus . Between patches, all pairwise comparisons, covering distances from few meters (between patches within locality) to 25 km (between localities), revealed significant genetic differentiation, a higher proportion of the molecular variance being explained by the comparisons between localities than within localities, in agreement with an isolation by distance model. Within patches, we found no significant correlation between individual pairwise spatial and genetic distances, except for the most polymorphic locus in the patch where the largest range of geographical distances had been analyzed. This study provides an estimation of the dispersal capacities of Abatus cordatus and highlights its low recolonization ability. Similar low recolonization capacities are thus expected in other Antarctic and Subantarctic brooding invertebrate species and suggest a high vulnerability of these species facing global change.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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Strandh Maria, Lannefors Mimi, Bonadonna Francesco, Westerdahl Helena, . (2011). Characterization of MHC class I and II genes in a subantarctic seabird, the blue petrel, Halobaena caerulea (Procellariiformes)
. Immunogenetics, 63(10), 653–666.
Abstract: The great polymorphism observed in the major histocompatibility complex (MHC) genes is thought to be maintained by pathogen-mediated selection possibly combined with MHC-disassortative mating, guided by MHC-determined olfactory cues. Here, we partly characterize the MHC class I and II B of the blue petrel, Halobaena caerulea (Procellariiformes), a bird with significant olfactory abilities that lives under presumably low pathogen burdens in Subantarctica. Blue petrels are long-lived, monogamous birds which suggest the necessity of an accurate mate choice process. The species is ancestral to songbirds (Passeriformes; many MHC loci), although not to gamefowls (Galliformes; few MHC loci). Considering the phylogenetic relationships and the low subantarctic pathogen burden, we expected few rather than many MHC loci in the blue petrel. However, when we analysed partial MHC class I and class II B cDNA and gDNA sequences we found evidence for as many as at least eight MHC class I loci and at least two class II B loci. These class I and II B sequences showed classical MHC characteristics, e.g. high nucleotide diversity, especially in putative peptide-binding regions where signatures of positive selection was detected. Trans-species polymorphism was found between MHC class II B sequences of the blue petrel and those of thin-billed prion, Pachyptila belcheri , two species that diverged 25 MYA. The observed MHC allele richness in the blue petrel may well serve as a basis for mate choice, especially since olfactory discrimination of MHC types may be possible in this species.
Keywords: Biomedical and Life Sciences,
Programme: 354
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Fonteneau Frédéric, Geiger Sylvie, Marion Loïc, Le Maho Yvon, Robin Jean-Patrice, Kinsella John, . (2011). Gastrointestinal helminths of King penguins (Aptenodytes patagonicus) at Crozet Archipelago
. Polar Biol., 34(8), 1249–1252.
Abstract: Communities of helminths are known to be related to feeding behaviors of hosts. While climate change and overfishing can impact food availability for Antarctic piscivorous predators, knowledge about infectious and parasitic diseases among Antarctic species is scarce or fragmentary. We studied the helminth community of King penguins ( Aptenodytes patagonicus ) from the Crozet Archipelago, the main breeding area of the species. Based on a sample of 41 individuals found freshly dead from predation or starvation, the gastrointestinal helminth community in King penguins was composed of 1 species of cestode ( Tetrabothrius wrighti ) and 2 species of nematodes ( Tetrameres wetzeli and Contracaecum heardi ). Cestodes formed the core of the helminth community (97.5% of worms collected) with a prevalence of infestation of 100% and a mean intensity of 178.6 worms per host. Sources of infestation and pathologies caused by these worms are also discussed.
Keywords: Biomedical and Life Sciences,
Programme: 119
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White J, Helfenstein F, Danchin E, Hatch S A, Wagner R H, . (2006). Sperm age and reproductive performance in a strictly monogamous bird – an experimental study
. J. Ornithol., 147(5), 88.
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Beaulieu Michaël, Thierry Anne-Mathilde, Handrich Yves, Massemin Sylvie, Maho Yvon, Ancel André, . (2009). Adverse effects of instrumentation in incubating Adélie penguins (Pygoscelis adeliae)
. Polar Biol., 33(4), 485–492.
Abstract: The use of data-loggers has permitted to explore the biology of free-ranging animals. However, this method has also been reported to reduce reproductive success while the reasons of this deleterious effect remain poorly documented. In this study, we aimed to identify critical periods of the breeding cycle of Ad,lie penguins (Pygoscelis adeliae) when the reproductive success may decrease because of instrumentation. For this purpose, we monitored 40 pairs, where one parent was instrumented before egg laying and 30 pairs without devices (controls). These pairs were followed at least during the incubation period but the majority was monitored during the entire breeding season. Reproductive success was affected in pairs where males were instrumented. This was not due to extra chick mortality during chick rearing but to a significantly lower hatching success. Moreover, the use of artificial eggs recording incubation temperatures and egg rotation indicated that in instrumented incubating males, eggs spent as much time at optimal incubation temperatures as control eggs but were rotated at a higher frequency. In Ad,lie penguins, males initiate incubation and it has been established that the early stage of incubation is one of the most critical periods for embryonic development. The low hatching rate observed in instrumented males was associated with a higher egg rotation rate, perhaps as a stress response to the presence of the instrument. Even though the causal effects remain unclear, instrumentation severely affected hatching success. For these reasons, we recommend equipping birds after the early incubation.
Keywords: incubation, instrumentation, penguin,
Programme: 137
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David B, Stock SR, De Carlo F, Hétérier V, De Ridder C, . (2009). Microstructures of Antarctic cidaroid spines: diversity of shapes and ectosymbiont attachments
. Mar. Biol., 156(8), 1559–1572.
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Thébault Erwan, Finlay Christopher C, Beggan Ciarán D, Alken Patrick, Aubert Julien, Barrois Olivier, Bertrand Francois, Bondar Tatiana, Boness Axel, Brocco Laura, Canet Elisabeth, Chambodut Aude, Chulliat Arnaud, Coïsson Pierdavide, Civet François, Du Aimin, Fournier Alexandre, Fratter Isabelle, Gillet Nicolas, Hamilton Brian, Hamoudi Mohamed, Hulot Gauthier, Jager Thomas, Korte Monika, Kuang Weijia, Lalanne Xavier, Langlais Benoit, Léger Jean-Michel, Lesur Vincent, Lowes Frank J, Macmillan Susan, Mandea Mioara, Manoj Chandrasekharan, Maus Stefan, Olsen Nils, Petrov Valeriy, Ridley Victoria, Rother Martin, Sabaka Terence J, Saturnino Diana, Schachtschneider Reyko, Sirol Olivier, Tangborn Andrew, Thomson Alan, Tøffner-Clausen Lars, Vigneron Pierre, Wardinski Ingo, Zvereva Tatiana, . (2015). International Geomagnetic Reference Field: the 12th generation
. Earth, Planets and Space, 67(1), 79.
Abstract: The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, provide the spherical harmonic coefficients, and provide maps of the magnetic declination, inclination, and total intensity for epoch 2015.0 and their predicted rates of change for 2015.0-2020.0. We also update the magnetic pole positions and discuss briefly the latest changes and possible future trends of the Earth’s magnetic field.
Programme: 139
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