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A new species Polacanthoderes shiraseae sp. nov. from three Antarctic regions (off Cape Darnley, off Totten Glacier, and in Lützow-Holm Bay) is described. In addition, type species of Polacanthoderes, Polacanthoderes martinezi, is redescribed. The new species is distinguished from P. martinezi by the presence of conspicuously thick lateroventral acicular spines on segments 8 and 9 and the presence of sublateral small acicular spines on segment 7. Both P. martinezi and P. shiraseae sp. nov. occasionally show intraspecific morphological variations in the position of some small acicular spines. The K2P genetic distances based on the mitochondrial cytochrome c oxidase subunit 1 gene sequences in P. shiraseae sp. nov. are 0–1.5%, equivalent to those in other echinoderid species. Phylogenetic analyses of Polacanthoderes based on the nuclear 18S rRNA and 28S rRNA gene sequences support the inclusion of the genus in Echinorhagata/Echinoderidae and suggest that the genus represents the most basal group of this order/family.

The 13th Symposium on Polar Science/Ordinary sessions [OB] Polar biology, Wed. 16 Nov.

Studies on the long-term survival of animals often focus on the specific instance of survival of animals only, and descriptions of subsequent reproduction are generally not reported. In this study, we recorded the reproductive performance of the first-generation offspring of the resuscitated individual (SB-1) and the hatchling of the resuscitated egg (SB-3) of the Antarctic tardigrade, Acutuncus antarcticus, after being frozen for 30.5 years. By providing further detailed description of the reproduction of SB-1 and SB-3 after revival, and then comparing the reproductive performance with that of their first-generation offspring, the possible indications of the damage accrued during the long-term preservation in SB-1 and SB-3 were more specifically detected. Additionally, the DNA analysis revealed two distinctively different mitochondrial genetic sequences of A. antarcticus between the SB strains and the LSW strain. The observed differences in some of the reproductive parameters between the two genetic types suggested a possible relationship between the life-history traits and genetic type in the species A. antarcticus. Further experiments using the SB-1 and SB-3 strains reared for a long period to exclude the instant effect of preservation are expected to improve our understanding of the mechanisms underlying the long-term survival of animals.

The 11th Symposium on Polar Science/Ordinary sessions: [OB] Polar Biology, Poster presentations, Mon. 16 Nov. - Fri. 18 Dec.

The 11th Symposium on Polar Science/Ordinary sessions: [OB] Polar Biology, Poster presentations, Mon. 16 Nov. - Fri. 18 Dec.

Two new cold-adapted yeast species, Cystobasidium tubakii sp. nov. and Cystobasidium ongulense sp. nov., were isolated from soil collected from East Ongul Island, East Antarctica, during the 49th Japanese Antarctic Research Expedition (JARE 49). Molecular analysis based on large subunit (LSU) D1/D2 domain and the combined sequences of small subunit (SSU) rDNA, internal transcribed spacer (ITS) region, LSU D1/D2 domain and TEF1 sequences showed that these species are novel. Both species could grow at sub-zero temperatures and in vitamin-free media. These characteristics were likely obtained by the yeasts to survive oligotrophic environments such as that in Antarctica. This is the first report of new fungal species isolated from near the Syowa station in the 60-y history of JARE.

The tardigrade class Mesotardigrada was erected on the basis of the description of Thermozodium esakii by Gilbert Rahm in 1937. In some characteristics, T. esakii is intermediate between members of the classes Eutardigrada and Heterotardigrada. The class Mesotardigrada is known only from Rahm's published drawings of T. esakii; no voucher specimens are known, and subsequent attempts to collect it at the locus typicus have been unsuccessful. Among the possible explanations for this situation are that Rahm may have collected specimens of a more typical tardigrade, but misinterpreted what he saw. Alternatively, changes in habitat in the area may have led to the tardigrade's extirpation. Perhaps T. esakii is a rare species, such that recent sampling efforts have been insufficient to rediscover it. Finally, Rahm's 1937 description may be an attempt at deception. Until physical evidence of T. esakii is found, the species, and by extension the class Mesotardigrada, should be considered nomen dubium.

A new species of free-living marine nematode, Oncholaimus langhovdensis sp. nov., is described from the intertidal zone of Langhovde (near Syowa Station), Dronning Maud Land, East Antarctica. It closely resembles 11 congeners in the conico-cylindrical tail shape present in males and amphid and excretory pore positions, short spicules, and Demanian system structure present in females. However, it mainly differs from these congeners in body size, de Man's ratios, tail length and shape, and Demanian system structure present in females. Oncholaimus langhovdensis sp. nov. also resembles four congeners known only by females, but it can be distinguished from them based on the tail length and uvette position. In addition to O. langhovdensis sp. nov., two undescribed species (Tripyloididae gen. sp. and Axonolaimidae gen. sp.) and four unidentified species (Sphaerolaimus sp., Oncholaimidae gen. sp., Comesomatidae gen. sp., and Chromadorida fam. gen. sp.) were found from the same locality.

The Ninth Symposium on Polar Science/Ordinary sessions: [OB] Polar biology, Wed. 5 Dec. / Entrance Hall (1st floor), National Institute of Polar Research

The Ninth Symposium on Polar Science/Ordinary sessions: [OB] Polar biology, Wed. 5 Dec. / Entrance Hall (1st floor), National Institute of Polar Research

The Antarctic heteronemertean Parborlasia corrugata (McIntosh, 1876) (originally Lineus corrugatus) shows a circumpolar distribution in the Southern Ocean, putatively with high dispersal capacity of the planktonic larva. From the eastern coast of Lutzow-Holm Bay near Syowa Station (69 degrees 00'S, 39 degrees 35'E), several records of heteronemerteans have been made under the name of Lineus corrugatus. However, they have never been explicitly identified by molecular data. In the present study, we determined a partial sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene for 11 specimens of P. corrugata collected from depths of 17-27 m under sea ice near Syowa Station. A haplotype-network analysis along with other COI sequences from 66 individuals collected at different places in the Antarctic and sub-Antarctic islands, available at public databases, resulted in that all the 11 specimens from Lutzow-Holm Bay possessed either of two major haplotypes detected in previous studies. It reflects the effective dispersal of the species between the localities including Lutzow-Holm Bay.

Reproductive output is one of the central attributes of life history, and knowledge of age-specific reproduction can enhance the understanding of population performance and dynamics. Tardigrades are microscopic invertebrates that live in marine, freshwater and terrestrial ecosystems. While changes in fertility in relation to age are known to occur in other invertebrate groups, the subject has not been specifically addressed in tardigrades. The current study demonstrates for the first time the effect of lifespan and age on reproductive characteristics of the tardigrade species, Acutuncus antarcticus (Richters 1904), based on the observation of individuals over their entire lifespan under constant environment conditions in the laboratory. Clutch size of A. antarcticus fluctuated conspicuously throughout individual lifespans. Weak effects of age were observed on oviposition interval and hatching success, with the former increasing slightly and the latter decreasing slightly with age. Numbers of oviposition events and eggs produced per individual varied greatly and were correlated with lifespan. No significant relationships between clutch size, hatching time or hatching success with lifespan were detected. The majority of the individuals continued oviposition until shortly before death, with no suggestion of a post-reproductive lifespan. Our observations suggest that any decline in fertility with age in this species of tardigrade is minimal. The study provides new insight into the reproductive biology and ageing of invertebrate species.

Tardigrades are found in most terrestrial and freshwater Antarctic ecosystems and are one of the most diverse and important groups of invertebrates in Antarctica. We developed a new laboratory system for rearing the Antarctic tardigrade Acutuncus antarcticus (Richters 1904), one of the most widespread and common Antarctic tardigrade species. To provide a description of the life history of this tardigrade, survival and reproduction of 68 individuals were observed and recorded daily at a constant temperature of 15 °C. The life-history data obtained are consistent with previous studies of other tardigrades. The exceptionally high hatching success obtained is suggested to be an important life-history characteristic of this species contributing to it often being a common and dominant species in the Antarctic habitats in which it occurs. Furthermore, high hatching success combined with very low variation in development time, under the protocol used in the current study, indicates that A. antarcticus may be a good model species for studies in developmental biology. Integrating data from this and previous studies, the importance of temperature on reproduction and growth in A. antarcticus was inferred. With terrestrial and freshwater ecosystems in some parts of Antarctica experiencing sometimes drastic contemporary climatic and environmental changes, studies of the effect of temperature on generation time and reproductive success in Antarctic tardigrades are urgently required, as these animals are important elements of community structure and function in polar ecosystems.

Extreme environments sometimes support surprisingly high meiofaunal diversity. We sampled runoff from the acidic hot springs of Unzen, Japan. This is the type locality of Thermozodium esakii Rahm, 1937, the only tardigrade in the class Mesotardigrada, which remains contentious in the absence of corroboration or supporting specimens. Our sampling revealed at least three species of arthropods, four rotifers, and five nematodes living in the hot (ca. 40°C) and acidic (ca. pH 2.5) water, but no tardigrades.

Tardigrades are important members of the simple terrestrial ecosystems in the extreme environments in Antarctica. This study provides a baseline description of tardigrade species diversity and distribution pattern within the terrestrial and lake environments of the coastal regions around Syowa Station and the neighbouring inland Sør Rondane Mountains, Dronning Maud Land. We combined data obtained from new and previously described collections and updated data available in the existing literature. We recorded five tardigrade species, three of which (Echiniscus pseudowendti Dastych 1984, Hebesuncus ryani Dastych and Harris 1994, Pseudechiniscus sp.) have not previously been reported from the area, increasing the total recorded tardigrade diversity for this region of continental Antarctica to ten species. The results of our study indicate that tardigrades have been and are major components of the lake environment community in continental Antarctica, with Acutuncus antarcticus (Richters 1904) the most common and dominant species. Our data confirm that the tardigrade species diversity in the vicinity of Syowa Station is very low and suggest potential relationships between individual tardigrade species and terrestrial moss species and depth in freshwater ecosystems.

Antarctic terrestrial ecosystems are not immune to the threat of biological invasions, and the urgent need for implementation of effective mitigation measures to minimize the risk has been highlighted. Recently, the transportation and logistic support system of the Japanese Antarctic Research Expedition has undergone substantial changes after the relocation of the cargo handling facility and the commissioning of a new icebreaker in 2009. The potential risk of introducing non-native species into Antarctica through the newly adopted cargo transportation system in comparison with the previously existing system was determined by quantifying both changes in the form of cargo transported and the frequency of propagule attachment on different types of cargo item. We obtained 1022 propagules of at least 26 species, including species known to have resistance to the stresses of cold environments. Larger numbers of propagules, and a greater proportion of affected cargo items, were encountered in the newly adopted transportation system than in its predecessor. The increased risks in the new system were identified as being associated with the major cargo packing type and the cargo storage location. Based upon those findings, we propose appropriate preventative measures in order to minimize the risk of transfer of non-native species into Antarctica.

Long-term survival has been one of the most studied of the extraordinary physiological characteristics of cryptobiosis in micrometazoans such as nematodes, tardigrades and rotifers. In the available studies of long-term survival of micrometazoans, instances of survival have been the primary observation, and recovery conditions of animals or subsequent reproduction are generally not reported. We therefore documented recovery conditions and reproduction immediately following revival of tardigrades retrieved from a frozen moss sample collected in Antarctica in 1983 and stored at −20 °C for 30.5 years. We recorded recovery of two individuals and development of a separate egg of the Antarctic tardigrade, Acutuncus antarcticus, providing the longest records of survival for tardigrades as animals or eggs. One of the two resuscitated individuals and the hatchling successfully reproduced repeatedly after their recovery from long-term cryptobiosis. This considerable extension of the known length of long-term survival of tardigrades recorded in our study is interpreted as being associated with the minimum oxidative damage likely to have resulted from storage under stable frozen conditions. The long recovery times of the revived tardigrades observed is suggestive of the requirement for repair of damage accrued over 30 years of cryptobiosis. Further more detailed studies will improve understanding of mechanisms and conditions underlying the long-term survival of cryptobiotic organisms.

NORPAC net samplings at three stations along a south-north transect on ca. 140°E were conducted in the Indian sector of the Southern Ocean from March 10 to 12 in 2002 during the 43rd Japanese Antarctic Research Expedition. The survey was held to examine the community structure and abundance of Copepoda in the seasonal ice zone of the Southern Ocean. A total of 15 species of copepod were identified at the stations. For nine species of copepod, Microcalanus pygmaeus, Calanus simillimus, Rhincalanus gigas, Euchaeta antarctica, Clausocalanus laticeps, Scolecithricella minor, Metridia lucens, Haloptilus oxycephalus and Oithona frigida, disparities of the distributions between the south of the Southern Boundary (SB) and the north became apparent. As here was a distinct difference of, about 2°C, in the sea surface temperature between the south and north of the SB, these disparities were considered to be influenced by the difference in the physical structure in the ocean, in particular by the water temperature, which was driven by the SB. Among Calanoides acutus, Calanus propinquus, and R. gigas, the earlier copepodite stages were observed at higher latitudes at all stations. This trend was considered to be a result of the sea ice retreat, which caused a later spawning period for Copepoda. In addition, an interaction between the sea ice conditions and the community structure of copepod along 140°E was suggested.

During the 43rd Japanese Antarctic Research Expedition(JARE) cruise on March 10-12 in 2002, NORPAC net samplings at three stations along a south-north transect, ca. 140°E in the Indian sector were conducted to survey zooplankton community structure and abundance in the seasonal ice zone(SIZ) of the Southern Ocean. A total of fourteen species/taxa were identified from the three stations. While copepods were numerically dominant at two stations(79.9% and 93.1% respectively of total abundance), appendicularians were found to be numerically dominant(84.0% of total abundance) at the southernmost station. This dominance of Appendicularia at this station suggested that Appendicularia is possibly an integral part of the community structure of the zooplankton in the SIZ. The Southern Boundary(SB) on the 140°E transect was found to be located at ～64.30°S and the southernmost station was located south of the SB while the two other stations were located north of the SB. Some species, such as Rhincalanus gigas, Calanus simillimus, Amphipoda, Euphausiacea, and Polychaeta, had distribution patterns that correlated with the position of the SB, therefore the SB is considered important in influencing the distribution of the zooplankton and its community structure in the SIZ.

A new species of polychaete, Flabegraviera fujiae sp. nov., is described and the first report of F. mundata (Gravier, 1906) from the shallow water around Syowa Station, Antarctica, is presented. Flabegraviera fujiae sp. nov. resembles F. profunda Salazar-Vallejo, 2012 but is discriminated from the latter by having eyes and an exposed cephalic cage. The specimen of F. mundata was collected from a depth of 8 m, providing the shallowest record of this species to date.

International audience; Despite considerable research on biological invasions, key areas remain poorly explored, especially ways to reduce unintentional propagule transfer. The Antarctic represents a microcosm of the situation, with the numbers of established non-native species growing. Information to help reduce potential impacts is therefore critical. We measured the propagule load of seeds, and fragments of bryophytes and lichens (the number of other plant or animal fragments was too low to draw any conclusions) carried in the clothing and gear of visitors to the Antarctic, during the 2007/08 austral summer. Samples were collected from different categories of visitors associated with national research programs and tourism and different categories of clothing and gear, new as well as used. We also collected information about the timing of travel and the regions visitors had travelled to prior to Antarctic travel. Seeds were found in 20% and 45% of tourist and science visitor samples, respectively. For bryophyte and lichen fragments the proportions were 11% and 20%, respectively. Footwear, trousers and bags belonging to field scientists were the highest risk items, especially of those personnel which had previously visited protected areas, parklands/botanic gardens or alpine areas. Tourists who visited rural/agricultural areas prior to travel, and/or travel with national programs or on smaller tourist vessels had the highest probability of transferring plant propagules. Travel either during the boreal or austral autumn months increased the probability of propagule presence. Our assessment is applicable to other areas given evidence of propagule transfer patterns in those areas that are broadly similar to those documented here. The current work provides a sound evidence base for both self-regulation (e.g. taking care of personal equipment) and organization-based regulation (e.g. issuing guidelines and holding regular inspections) to reduce propagule transfer of plants to the Antarctic.

Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year's first season (2007–2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica's climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios Scenario A1B [Nakićenović N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (∼33,054) are higher than those of scientists (∼7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent's climate changes.

International audience; To understand fully the risk of biological invasions, it is necessary to quantify propagule pressure along all introduction pathways. In the Antarctic region, importation of fresh produce is a potentially high risk, but as yet unquantified pathway. To address this knowledge gap, >11,250 fruit and vegetables sent to nine research stations in Antarctica and the sub-Antarctic islands, were examined for associated soil, invertebrates and microbial decomposition. Fifty-one food types were sourced from c. 130 locations dispersed across all six of the Earth's inhabited continents. On average, 12% of food items had soil on their surface, 28% showed microbial infection resulting in rot and more than 56 invertebrates were recorded, mainly from leafy produce. Approximately 30% of identified fungi sampled from infected foods were not recorded previously from within the Antarctic region, although this may reflect limited knowledge of Antarctic fungal diversity. The number of non-native flying invertebrates caught within the Rothera Research Station food storage area was linked closely with the level of fresh food resupply by ship and aircraft. We conclude by presenting practical biosecurity measures to reduce the risk of non-native species introductions to Antarctica associated with fresh foods.

Antarctic terrestrial ecosystems are not immune to the threat of biological invasions, and the urgent need for implementation of effective mitigation measures to minimize the risk of these occurring has been highlighted. Although many of the national operators and independent tour operators that transport personnel and/or cargo into Antarctica have implemented various bio-security procedures in recent years in order to reduce the risk of non-native species introductions, to date no specific bio-security policy or measure has been considered or adopted in the Japanese Antarctic Research Expedition (JARE) operation. In this study, risk of transporting non-native species into Antarctica was identified from the various perspectives associated with the activities of the JARE operations.First, a non-native flowering plant found near Syowa Station was examined in order to identify the species as well as to specify the source of introduction. The species of the grass which was once assigned as Poa cf. trivialis L. was determined based upon the morphological characteristics with the additional examination of the molecular systematics. The results of the study indicated the grass found growing near Syowa Station in Antarctica in 1995 to be included in the Svalbard salt marsh grass, Puccinellia svalbardensis Rønning, endemic to Spitzbergen, Svalbard in Arctic. Whereas a particular dispersal pathway of introducing the Arctic plant into Antarctica was not specified, a possibility of introduction of this species in association with the human activities was considered. The limited development of reproductive organs observed in the grass suggested a possibility of the environmental conditions in the continental Antarctica having prohibited the grass from the successful establishment in the region. However, the successful introduction of an endemic Arctic species in the continental Antarctic region, where no higher plants had previously been reported, demonstrated the considerable risk of introducing non-native species from Arctic into Antarctic. Second, the potential risk of non-native species introduction into Antarctica associated with the current JARE transportation operations was determined. The first part of this study was conducted on the clothing and equipment of the JARE expeditioners on board Shirase under the JARE 49 operation, southbound to Antarctica in the 2007/08 austral summer. The study focused on quantifying propagule attachment and carriage on the various types of clothing and equipment item. The data obtained were combined with characteristics of those items in order to identify those elements posing the significant risk of non-native species transport and introduction in association with the JARE expeditionrs transfer. Number of propagules collected from the clothing and gears of JARE expeditioners examined in this study was found less severe as compared with those results in the similar studies carried out by the other national Antarctic operations. The particular system of JARE operations, under which expeditioners are mostly issued new items, appears to have resulted in the very limited number of propagules encountered on their items. The risk of transporting propagules found in this study was associated with items which had previously been used. The latter part of this study was conducted on the transportation operations to Antarctica under both the old (JARE 49, southbound to Antarctica in the 2007/08 austral summer) and the new systems (JARE 51, 2009/10) in order to identify any specific risks associated with the current and newly-adopted system relative to its predecessor. The study again focused on quantifying propagule attachment and carriage here on the outer surfaces of various types of cargo item. The data obtained were combined with a compositional survey of cargo according to packing types and storage locations in order to identify those elements posing the most significant risk associated with the JARE cargo transport operations. The propagules found attached on the JARE cargo items including species known to have resistance to the stresses of cold environments indicated the potential pressure and risk of those propagules to the Antarctic ecosystem. The highest risk of carrying propagules was associated with the JARE Steel Containers (JARE SCs) especially the larger 12ft containers stored in the open air. The study also demonstrated the increased use of JARE SCs resulting in an increase in the total exposed cargo surface area in the current operation, which in consequence would significantly elevate the risk of non-native species propagule entrainment and transport in the current JARE logistic operation. While the outer structure of the JARE SCs and the location and the structure of the new storage facilities in Tachikawa-shi were considered potential major factors contributing to the large number of propagules obtained in the current system, the higher level of cargo control possible by National Institute of Polar Research (NIPR) under the current JARE Cargo transportation operation was shown.Third, a systematic survey was conducted among four national Antarctic operators, NIPR, Australian Antarctic Division, British Antarctic Survey, and Korea Polar Research Institute in order to assist with the development of best-practice guidelines of bio-security measures to minimize risk of transporting non-native species into Antarctica for the JARE operation. For those categories already identified as potential vectors of transporting non-native species in the previous studies including fresh food, cargo transportation, clothing and equipment of expeditioners, vehicles and ships, bio-security measure of those four operators were compared. Numbers and contents of bio-security measures developed and implemented varied across the four institutions surveyed, and institutions holding stations of historically or currently impacted by non-native species have developed and implemented various management plan and bio-security measures. Although the current policy on expeditioners at NIPR found to be fairly advanced and ideal to avoid the introduction of non-native species into Antarctica, numbers of policies and measures already adapted by other institutions were recommended to be implemented for the JARE operation on other categories. The study provided the plenty of scope for development and improvement of bio-security policies or measures to minimize risk of transporting non-native species into Antarctica to be adopted for the JARE operations. Consideration as well as the development of bio-security measures for the JARE operations based-upon the data presented was highly recommended.This study is the first to have demonstrated the particular risk of transporting propagules associated with the national operations conducting scientific research in polar regions based upon the actual occurrence of an introduced species in Antarctica. The study also provided an overview of the potential propagule pressures in association with the expeditioners and cargo transportation under the current JARE operation. Furthermore, numbers of appropriate preventative measures were proposed for adoption into the JARE operation based upon the findings in order to minimize the risk of transfer of non-native species into Antarctica through the activities of JARE. This study has established a platform for developing the management framework to prevent the introduction of non-native species into Antarctica for the JARE operation.