Entity

Time filter

Source Type

Saint Andrews, United Kingdom

The hydroid and early medusa stages of the deep sea hydrozoan jellyfish Earleria purpurea (Hydrozoa: Mitrocomidae) are described. Mature medusae were collected from the Monterey Bay submarine canyon near Monterey, California, USA utilizing a remotely operated vehicle and returned to the laboratory for culturing. In vitro fertilized eggs developed into free-swimming planulae larvae that settled and metamorphosed into benthic hydroid colonies consisting of feeding hydranths and medusa producing gonangia. Newly released medusae were grown to maturity and placed on educational display at the Monterey Bay Aquarium. The hydranths and gonangia were compared and found to be distinct from those of E. corachloeae the only other member of the Genus Earleria with a described life cycle. Copyright © 2011 Magnolia Press. Source


Sperstad S.V.,University of Tromso | Smith V.J.,Scottish Oceans Institute | Stensvag K.,University of Tromso
Developmental and Comparative Immunology | Year: 2010

Circulating haemocytes play major roles in the host defense reactions of decapods, including the synthesis and release of antimicrobial peptides (AMPs). Unlike the AMPs from insects, those in decapods are constitutively expressed. This study aims to establish primary cell cultures of the three main haemocyte types in Hyas araneus haemocytes, and to measure the in vitro expression of AMP genes in the cells following microbial challenge. The haemocyte populations were separated on Percoll gradients and cultured in modified L-15 medium. Expression analysis by real-time RT-PCR showed that the granular cells are the main producers of crustin, hyastatin and arasin 1 AMPs, but the hyaline cells and semigranular cells also show some expression of these genes. Incubating the cell populations with Aerococcus viridans var. homari (a Gram-positive bacterium) or Listonella anguillarum (a Gram-negative pathogen) provoked no dramatic changes in the gene expression of any of the AMP, and although there was a small (single doubling) significant increase in expression of the crustin gene in granular cells 24 h after exposure to L. anguillarum, it is unclear if this is biologically relevant under in vitro conditions. The results presented in this study are in accordance with several in vivo studies. © 2010. Source


Paterson D.M.,Marine Alliance for Science and Technology for Scotland | Paterson D.M.,Scottish Oceans Institute | Hanley N.D.,Marine Alliance for Science and Technology for Scotland | Hanley N.D.,University of Stirling | And 6 more authors.
Marine Ecology Progress Series | Year: 2011

Coastal zone ecosystems and the goods and services they provide are under increasing pressure from anthropogenic impacts. Climate change and demographic effects are particularly relevant, and it is critical to establish proper control systems (policies) to protect and conserve the wideranging benefits that these systems provide. The concept of 'holistic assessment', the Ecosystem Approach, is now being widely promoted, but the relationship between the science supporting this policy and the development of the policy itself is not always well-coordinated. This Theme Section discusses applications of science to coastal zone management and provides a critique of some approaches. © Inter-Research 2011. Source


Harris D.,University of St. Andrews | Matias L.,University of Lisbon | Thomas L.,University of St. Andrews | Harwood J.,Scottish Oceans Institute | Geissler W.H.,Alfred Wegener Institute for Polar and Marine Research
Journal of the Acoustical Society of America | Year: 2013

Automated methods were developed to detect fin whale calls recorded by an array of ocean bottom seismometers (OBSs) deployed off the Portuguese coast between 2007 and 2008. Using recordings collected on a single day in January 2008, a standard seismological method for estimating earthquake location from single instruments, the three-component analysis, was used to estimate the relative azimuth, incidence angle, and horizontal range between each OBS and detected calls. A validation study using airgun shots, performed prior to the call analysis, indicated that the accuracy of the three-component analysis was satisfactory for this preliminary study. Point transect sampling using cue counts, a form of distance sampling, was then used to estimate the average probability of detecting a call via the array during the chosen day. This is a key step to estimating density or abundance of animals using passive acoustic data. The average probability of detection was estimated to be 0.313 (standard error: 0.033). However, fin whale density could not be estimated due to a lack of an appropriate estimate of cue (i.e., vocalization) rate. This study demonstrates the potential for using a sparse array of widely spaced, independently operating acoustic sensors, such as OBSs, for estimating cetacean density. © 2013 Acoustical Society of America. Source


Barlow J.,Southwest Fisheries Science Center | Tyack P.L.,Scottish Oceans Institute | Johnson M.P.,Scottish Oceans Institute | Baird R.W.,Cascadia Research Collective | And 3 more authors.
Journal of the Acoustical Society of America | Year: 2013

Acoustic survey methods can be used to estimate density and abundance using sounds produced by cetaceans and detected using hydrophones if the probability of detection can be estimated. For passive acoustic surveys, probability of detection at zero horizontal distance from a sensor, commonly called g(0), depends on the temporal patterns of vocalizations. Methods to estimate g(0) are developed based on the assumption that a beaked whale will be detected if it is producing regular echolocation clicks directly under or above a hydrophone. Data from acoustic recording tags placed on two species of beaked whales (Cuvier's beaked whale - Ziphius cavirostris and Blainville's beaked whale - Mesoplodon densirostris) are used to directly estimate the percentage of time they produce echolocation clicks. A model of vocal behavior for these species as a function of their diving behavior is applied to other types of dive data (from time-depth recorders and time-depth-transmitting satellite tags) to indirectly determine g(0) in other locations for low ambient noise conditions. Estimates of g(0) for a single instant in time are 0.28 [standard deviation (s.d.) = 0.05] for Cuvier's beaked whale and 0.19 (s.d. = 0.01) for Blainville's beaked whale. © 2013 U.S. Government. Source

Discover hidden collaborations