Keyword

EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES

116 record(s)
 
Type of resources
Topics
Keywords
Contact for the resource
Provided by
From 1 - 10 / 116
  • Metadata record for data from ASAC Project 668 See the link below for public details on this project. From the abstracts of some of the referenced papers: Body shrinkage may be one of the strategies that Antarctic krill use to cope with food scarcity, particularly during winter. Despite their demonstrated ability to shrink, there are only very limited data to determine how commonly shrinkage occurs in the wild. It has been previously shown that laboratory-shrunk krill tend to conserve the shape of the eye. This study examined whether the relationship between the eye diameter and body length could be used to detect whether krill had been shrinking. By tracking individuals over time and examining specimens sampled as groups, it was demonstrated that fed and starved krill are distinguishable by the relationship between the eye diameter and body length. The eye diameter of well-fed krill continued to increase as overall length increased. This created a distinction between fed and starved krill, while no separation was detected in terms of the body length to weight relationship. Eye growth of krill re-commenced with re-growth of krill following shrinkage although there was some time lag. It would take approximately 2 moult cycles of shrinkage at modest rates to significantly change the eye diameter to body length relationship between normal and shrunk krill. If krill starve for a prolonged period in the wild, and hence shrink, the eye diameter to body length relationship should be able to indicate this. This would be particularly noticeable at the end of winter. A series of experiments was carried out to examine the relationship between feeding, moulting, and fluoride content in Antarctic krill (Euphausia superba). Starvation increased the intermolt period in krill, but had no effect on the fluoride concentration of the moults produced. Addition of excess fluoride to the sea water had no direct effect on the intermoult period, the moult weight, or moult size. Additions of 6 micrograms per litre and 10 micrograms per litre fluoride raised the fluoride concentrations of the moults produced and the whole animals. The whole body fluoride content varied cyclically during the moult cycle, reaching a peak 6 days following ecdysis. Fluoride loss at ecdysis could largely be explained by the amount of this ion shed in the moult.

  • Percent-cover estimates from forward facing still-images collected during the benthic trawls of the 2007/08 CEAMARC voyage (raw data-set here: https://data.aad.gov.au/metadata/records/CEAMARC_CASO_200708_V3_IMAGES). All fauna in the bottom third of each image was scored to the lowest taxonomic resolution possible. The images originate from 32 transects, but were split by their lon-lat-position within a spatial grid of environmental variables into 41 sites. This dataset contains: (1) - species/ morphotypes identified to the highest taxonomic resolution possible - broader taxonomic classification (phylum/class) - each species mobility, feeding-type and body-shape if possible - average abundances in percent-cover at each site (2) - the mean longitude of all images aggregated per site - the mean latitude of all images aggregated per site - the number of images scored per site

  • This dataset is a document describing the Metazoan Zooplankton of the Southern Ocean. It lists all the known species and with illustrated diagrams provides a guide to their taxonomic identification. The document is available for download as a pdf from the provided URL.

  • This dataset contains results from the Antarctic Division Biomass Experiment (ADBEX I) cruise of the Nella Dan. This cruise is the second in a series of six cruises, and follows the First International BIOMASS Experiment (FIBEX) in early 1981, documentation of which can be found in ANARE Research Notes 7, or by searching the metadata records for FIBEX. ADBEX I operated between November and December 1982, and studied the distribution and abundance of krill (Euphausia superba). Surveys of krill and other zooplankton were taken off Antarctica in the Australian sector (Mawson to Davis region) and Prydz Bay. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa marcuria. Other pteropods and cephalopods were also studied. Physical and chemical oceanography data were also obtained at some stations, as well as phytoplankton samples. Summary results are listed in the documentation.

  • A meta-analysis was undertaken to examine the vulnerability of Antarctic marine biota occupying waters south of 60 degrees S to ocean acidification. Comprehensive database searches were conducted to compile all English language, peer-reviewed journals articles and literature reviews that investigated the effect of altered seawater carbonate chemistry on Southern Ocean and/or Antarctic marine organisms. A document detailing the methods used to collect these data is included in the download file.

  • Metadata record for data from ASAC Project 2897 See the link below for public details on this project. Public The aim of this multi-disciplinary proposal is to examine the molecular evolution of toxic proteins across the full taxonomical spectrum of venomous Antarctic marine animals. The project will create a comparative encyclopedia of the evolution of the venom system in the Antarctic marine animal kingdom and elucidate the underlying structure-function relationships between these toxic proteins. Through a process utilising cutting edge analytical techniques, such as cDNA cloning and molecular modelling, a feedback loop of bioactivity testing will be created to contribute substantially towards the area of drug design and development from toxic animal peptides. Project objectives: The aim of this project is to investigate the evolution of the molecular, structural and functional properties of Antarctic marine animal venom systems. This integrative project aims to investigate the origin and evolution of secreted proteins in the venom glands of toxic polar animals by means of: - Analysis of mechanisms of evolution in multigene families. - Phylogenetic analysis of evolutionary relationships among secreted proteins in the venom glands of major lineages; - Search for correlations between: (i) evolution of venom gland structure (ii) molecular evolution of venom components, and (iii) ecological specialisation of the animal - Bioactivity studies will be conducted upon representative purified or synthesised proteins. - A first ever comparison of the convergent strategies between Arctic and Antarctic endemic fauna. The results will help us to understand protein evolution, will cast light on the classic problem of how venom systems evolve, and may provide leads in the search for commercially-exploitable venom proteins. Taken from the 2008-2009 Progress Report: Progress against objectives: We have completed the genetic analyses of the specimens and sequence analyses. Phylogenetic positioning is robust other than a few deep level nodes. We are undertaking a second round of genetic analyses using different primers in order to resolve these nodes. Biochemical analyses of crude protein secretions from the posterior salivary (venom) glands has revealed temperature specific modifications of some of the venom components to adapt them to the polar conditions. We have tested the secretions in a battery of assays. We are now repeating those assays using purified proteins in order to determine which types are responsible for particular effects and also investigate synergistic interactions. Taken from the 2009-2010 Progress Report: Progress against objectives: We have undertaken genetic analyses of the specimens collected, and investigated specific adaptations of their venom systems. Results to-date include: - Antarctic octopuses are more genetically diverse than previously appreciated, including at least one new genus - an inverse relationship exists between the size of the venom gland and the size of the beak - their venoms have undergone temperature-specific adaptations

  • Metadata record for data from ASAC Project 1117 See the link below for public details on this project. ---- Public Summary from Project ---- The aim of this project is to determine how feasible it is to regularly sample the pelagic under-ice community during winter at a coastal site near Mawson. Very few attempts have been made to sample the water column under the ice during the winter months and the processes that occur during this period remain critical gaps in our knowledge of the Antarctic marine ecosystem. ------------------------------------- The pelagic community under the Mawson sea ice was sampled during the winter of 2001 using 'light trap' sampling devices. The 'light traps' were tested at various depths in a range of configurations to determine whether they were an appropriate instrument to sample the winter pelagic community under the ice. Fourteen successful deployments of the light traps were made on seven separate occasions from 12 June to 12 September 2001. The light traps were deployed at three different depths - the underside of the sea ice, mid water, and just above the sea floor. Two different light sources were used to attract the animals, namely fluorescent tubes and cyalume sticks. Two different configurations of the traps were tested to retain the animals inside the trap - one with plastic flaps to trap the animals, the other with no flaps, allowing the animals to move freely inside the trap. The light traps were deployed and retrieved during darkness to avoid any influence of ambient light. The objectives of the project were met and it is assessed that the pelagic community in winter can be effectively sampled using this methodology. A result of particular interest is the success of the traps in capturing Pleuragramma antarctica, a species which has proven difficult to capture using traditional sampling methods such as nets.

  • Metadata record for data from ASAC Project 38 See the link below for public details on this project. From the abstracts of the referenced papers: The origin of echinoderms from Macquarie Island in the Southern Ocean is analysed through a novel application of multivariate statistics. Ordinations are produced from a combination of species distribution, bathymetric, habitat and life history data in order to assess patterns of migration. The analyses distinguish groups of species derived from the Kerguelen Plateau, New Zealand and eastern Antarctica. These groups correlate with attributes expected for epiplanktonic dispersal and range expansion along the North and South Macquarie Ridges respectively. There is no convincing evidence for long-distance pelagic dispersal, migration from the abyssal plain or for human translocation of species. The results indicate that taxonomic groups differ in their ability to disperse, and emphasise the importance of depth in biogeographical analyses. Dispersal by range expansion appears to have been more significant than epiplanktonic dispersal and vicariant rather than long-distance dispersal mechanisms are the preferred explanation for some disjunct distribution patterns. Fifty two echinoderm species are recorded from off Macquarie Island and the Macquarie Ridge in the Southern Ocean. One new asteroid Odontohenricia anarea sp. nov. and one new holothurian Trachythyone nelladana sp. nov. are described. The asteroid genus Calvasterias is synonymised with Anasterias. The asteroids Cycethra macquariensis and Asterina hamiltoni are synonymised with Asterina frigida and placed in the same genus Cycethra. The asteroid Ceramaster lennoxkingi is synonymised with C. patagonicus, Solaster dianae with S. notophrynus, and Anasterias sphoerulatus with A. mawsoni. The asteroids Psilaster charcoti, Odontaster penicillatus, Ceramaster patagonicus, Crossaster multispinus, Solaster notophrynus, Pteraster affinis, Henricia studeri, the ophiuroid Ophioplocus incipiens, and the holothurians Paelopatides ovalis, Synallactes challengeri, Laetmogone sp, Taeniogyrus sp are recorded from the island for the first time. The following species previously recorded from Macquarie Island have been re-identified: the asteroids Odontaster auklandensis (=O. penicillatus), Henricia aucklandiae (=H. studeri), Henricia lukinsi (=H. obesa), Smilasterias irregularis (=S. clarkailsa), Anasterias antarctica (=A. directa), and the ophiuroid Ophiacantha pentagona (=O. vilis). The existence at Macquarie Island of the species Hymenaster sp, Goniocidaris umbraculum and Ocnus calcareus require confirmation. The asteroids Anasterias mawsoni, Pteraster affinis, Porania antarctica and Odonaster meridionalis are reported from the shore around Heard Island. The ecology and relationships of echinoderms from Macquarie Island are discussed.

  • This data were collected on the sixth Nella Dan voyage of a long term field survey project being conducted by the Australian Antarctic Division, to collect distribution, abundance and population structure data for the krill Euphausia superba in the Prydz Bay region, Antarctica. This voyage, the Australian Antarctic Marine Biological Ecosystem Research 1986/1987 (AAMBER 86/87) cruise, operated between February and April 1987. During March, a survey of the krill population and zooplankton community was conducted, to determine the late summer distribution and abundance of krill, especially the larvae. This was done as a follow up to SIBEX II in mid-summer (Janurary) 1985. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa marcuria. Phytoplankton pigment analysis was also conducted at each CTD station site.

  • Metadata record for data from AAS (ASAC) project 3051. Public Environmental change is by far one of the major crises facing our planet in recent times. This project will contribute specifically to understanding the effects of climate change and other human-induced impacts on marine species in Antarctica. Through studying key ecological and biological processes in marine benthic invertebrates we will better understand the spatial scale of populations, the nature of the processes that maintain those populations, how environmental change will affect those processes, and the levels of genetic diversity and resilience in Antarctic marine communities. Taken together this information will enable better, more informed management of Antarctic marine ecosystems. Project objectives: The project objectives, as stated in the project application round 2008/09, appear below: This project will combine experimental tests of demographic change with genetic tests of population isolation and diversity to enable predictions of the resilience of Antarctic marine invertebrates to current and predicted environmental change. The specific objectives of the project are; 1. Effects of change. Understand the effects of environmental change on reproduction (fecundity, reproductive success) and the early life history (larval behaviour, survivorship, and recruitment) of key Antarctic marine benthic invertebrates. 2. Isolation. Determine the degree of isolation/connectivity among populations as well as the levels of genetic diversity of key Antarctic marine benthic invertebrates. 3. Resilience. Assess the resilience (ability to cope with or adapt) of Antarctic marine benthic invertebrates to environmental change. 4. Practical Outcomes. Develop improved predictive capacity to contribute towards the development of management strategies for the conservation of Antarctic marine benthic invertebrates. Taken from the 2008-2009 Progress Report: Progress against objectives: This project commenced in 2008/9. Objective 1 - Effects of change - Collected live echinoderms (Abatus spp, Sterechinus numeyeri, Diploasterias) from around Casey Station and transported these on the A319 back to Kingston. A preliminary fertilisation trial has been run using Sterechinus individuals, and the remaining individuals are now being maintained in aquaria for future reproductive studies. Objective 2 - Isolation - Tissue samples from over 200 Sterechinus numeyeri were collected from 5 sites around Casey Station. These will form the foundation for genetic connectivity studies, and will complement exisiting Abatus samples from the same location. Laboratory processing of these samples has commenced, and development of microsatellite markers for both species is underway. Objectives 3 and 4 represent late-stage components of the project, so no progress can be reported on these at this stage. Taken from the 2009-2010 Progress Report: Progress against the objectives: Objective 1 - Effects of change - Collected live urchins (Abatus spp and Sterechinus numeyeri) from around Davis Station. Ran a series of spawning trials, although these were largely unsuccessful, with most individuals having spawned prior to the beginning of the season. We ran one successful fertilisation trial with S. neumeyeri to look at the effects of water temperature and salinity on fertilisation success. Preliminary analysis of the data indicates these environmental parameters do have an effect on fertilisation. Objective 2 - Isolation - Tissue samples from over 350 Sterechinus numeyeri were collected from 12 sites around Davis Station. These will be used for genetic connectivity studies, and will complement samples collected from Casey in the previous season. Larval Sterechinus were also collected from the water column and preserved for genetic analysis along with adult and juvenile Abatus ingens. Microsatellite markers (11 polymorphic loci) have now been developed for Sterechinus, and microsatellite deveopment is partially completed for Abatus ingens; the library has been created but optimisation of loci still needs to be done. We have completed DNA sequencing for Sterechinus and Abatus from Casey Station for 1 gene region (16S) and are optimising an additional 2 regions. This will be used to compare populations from Davis and Casey to understand large-scale connectivity. Objectives 3 and 4 represent late-stage components of the project. As this is only the second year of a 5-year programme, no progress can be reported on these at this stage.