GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Insect Physiology 57 (2011): 665-675, doi:10.1016/j.jinsphys.2011.03.007.
    Description: Calanoid copepods, such as Calanus finmarchicus, are a key component of marine food webs. C. finmarchicus undergoes a facultative diapause during juvenile development, which profoundly affects their seasonal distribution and availability to their predators. The current ignorance of how copepod diapause is regulated limits understanding of copepod population dynamics, distribution, and ecosystem interactions. Heat shock proteins (Hsps) are a superfamily of molecular chaperones characteristically upregulated in response to stress conditions and frequently associated with diapause in other taxa. In this study, 8 heat shock proteins were identified in C. finmarchicus C5 copepodids (Hsp21, Hsp22, p26, Hsp90, and 4 forms of Hsp70), and expression of these transcripts was characterized in response to handling stress and in association with diapause. Hsp21, Hsp22, and Hsp70A (cytosolic subfamily) were induced by handling stress. Expression of Hsp70A was also elevated in shallow active copepodids relative to deep diapausing copepodids, which may reflect induction of this gene by varied stressors in active animals. In contrast, expression of Hsp22 was elevated in deep diapausing animals; Hsp22 may play a role both in short-term stress responses and in protecting proteins from degradation during diapause. Expression of most of the Hsps examined did not vary in response to diapause, perhaps because the diapause of C. finmarchicus is not associated with the extreme environmental conditions (e.g., freezing, desiccation) experienced by many other taxa, such as overwintering insects or Artemia cysts.
    Description: Funding for AMA was provided by the WHOI Summer Student Fellowship Program and an EPA STAR fellowship.
    Keywords: Copepod ; Crustacean ; Diapause ; Heat shock protein ; Stress response
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2012. This article is posted here by permission of Inter-Research. The definitive version was published in Marine Ecology Progress Series 459 (2012): 135-156, doi:10.3354/meps09675.
    Description: Mammalian reproduction is metabolically regulated; therefore, the endangered status and high variability in reproduction of North Atlantic right whales Eubalaena glacialis necessitate accurate assessments at sea of the nutritional condition of living individuals. Aerial photogrammetry was used to measure dorsal body width at multiple locations along the bodies of free-swimming right whales at different stages of the female reproductive cycle (E. glacialis) and during the initial months of lactation (mother and calf Eubalaena australis) to quantify changes in nutritional condition during energetically demanding events. Principal components analyses indicated that body width was most variable at 60% of the body length from the snout. Thoracic, abdominal and caudal body width of E. australis thinned significantly during the initial months of lactation, especially at 60% of body length from the snout, while their calves’ widths and width-to-length ratios increased. The body shape of E. glacialis that had been lactating for 8 mo was significantly thinner than non-lactating, non-pregnant E. glacialis. Body shape of E. glacialis measured in the eighth month of lactation was significantly thinner than that of E. australis in the first month, but did not differ from that of E. australis in the third and fourth months. Body width was comparable with diameter calculated from girth of carcasses. These results indicate that mother right whales rely on endogenous nutrient reserves to support the considerable energy expenditure during the initial months of lactation; therefore, photogrammetric measurements of body width, particularly at 60% of body length from the snout, are an effective way to quantitatively and remotely assess nutritional condition of living right whales.
    Description: This project was made possible with funds provided by the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, the Northeast Consortium, and the Hussey Foundation through the Ocean Life Institute at Woods Hole Oceanographic Institution.
    Keywords: Right whale ; Body shape ; Body condition ; Aerial photogrammetry ; Reproduction ; Energetics ; Eubalaena
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2022-05-26
    Description: Author Posting. © Inter-Research, 2013. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 490 (2013): 267-284, doi:10.3354/meps10457.
    Description: Due to the seriously endangered status of North Pacific right whales Eubalaena japonica, an improved understanding of the environmental factors that influence the species’ distribution and occurrence is needed to better assess the effects of climate change and industrial activities on the population. Associations among right whales, zooplankton, and the physical environment were examined in the southeastern Bering Sea during the summers of 2008 and 2009. Sampling with nets, an optical plankton counter, and a video plankton recorder in proximity to whales as well as along cross-isobath surveys indicated that the copepod Calanus marshallae is the primary prey of right whales in this region. Acoustic detections of right whales from sonobuoys deployed during the cross-isobath surveys were strongly associated with C. marshallae abundance, and peak abundance estimates of C. marshallae in 2.5 m depth strata near a tagged right whale ranged as high as 106 copepods m-3. The smaller Pseudocalanus spp. was higher in abundance than C. marshallae in proximity to right whales, but significantly lower in biomass. High concentrations of C. marshallae occurred in both the surface and bottom layers of the highly stratified water column, but there was no evidence of diel vertical migration. Instead, occurrence of C. marshallae in the bottom layer was associated with elevated near-bottom light attenuance and chlorophyll fluorescence, suggesting C. marshallae may aggregate at depth while feeding on resuspended phytodetritus. Despite the occasional presence of strong horizontal gradients in hydrographic properties, no association was found between C. marshallae and either fronts or phytoplankton distribution.
    Description: This study was funded by the US Depart - ment of the Interior, Minerals Management Service (MMS; now Bureau of Ocean Energy Management), through Interagency Agreement No. M07RG13267 (AKC 063) with the US Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), as part of the MMS Alaska Environmental Studies Program.
    Keywords: Eubalaena japonica ; Right whale ; Calanus marshallae ; Calanus glacialis ; Bering Sea ; Baleen whale ; Resuspension ; Phytodetritus
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Zoology 11 (2014): 91, doi:10.1186/s12983-014-0091-8.
    Description: Calanus finmarchicus, a highly abundant copepod that is an important primary consumer in North Atlantic ecosystems, has a flexible life history in which copepods in the last juvenile developmental stage (fifth copepodid, C5) may either delay maturation and enter diapause or molt directly into adults. The factors that regulate this developmental plasticity are poorly understood, and few tools have been developed to assess the physiological condition of individual copepods. We sampled a cultured population of C. finmarchicus copepods daily throughout the C5 stage and assessed molt stage progression, gonad development and lipid storage. We used high-throughput sequencing to identify genes that were differentially expressed during progression through the molt stage and then used qPCR to profile daily expression of individual genes. Based on expression profiles of twelve genes, samples were statistically clustered into three groups: (1) an early period occurring prior to separation of the cuticle from the epidermis (apolysis) when expression of genes associated with lipid synthesis and transport (FABP and ELOV) and two nuclear receptors (ERR and HR78) was highest, (2) a middle period of rapid change in both gene expression and physiological condition, including local minima and maxima in several nuclear receptors (FTZ-F1, HR38b, and EcR), and (3) a late period when gonads were differentiated and expression of genes associated with molting (Torso-like, HR38a) peaked. The ratio of Torso-like to HR38b strongly differentiated the early and late groups. This study provides the first dynamic profiles of gene expression anchored with morphological markers of lipid accumulation, development and gonad maturation throughout a copepod molt cycle. Transcriptomic profiling revealed significant changes over the molt cycle in genes with presumed roles in lipid synthesis, molt regulation and gonad development, suggestive of a coupling of these processes in Calanus finmarchicus. Finally, we identified gene expression profiles that strongly differentiate between early and late development within the C5 copepodid stage. We anticipate that these findings and continued development of robust gene expression biomarkers that distinguish between diapause preparation and continuous development will ultimately enable novel studies of the intrinsic and extrinsic factors that govern diapause initiation in Calanus finmarchicus.
    Description: This work was supported by grant number OCE-1132567 from the National Science Foundation to MFB and AMT. Additional supported was provided by WHOI Early Career Scientist Awards provided to MFB and AMT.
    Keywords: Arthropod ; Crustacean ; Gene expression ; Molt cycle ; Transcriptomics
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/vnd.ms-excel
    Format: text/plain
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2022-05-26
    Description: Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Philosophical Transactions of the Royal Society B 372 (2017): 20160067, doi:10.1098/rstb.2016.0067.
    Description: North Atlantic right whales (Eubalaena glacialis) feed during the spring and early summer in marine waters off the northeast coast of North America. Their food primarily consists of planktonic copepods, Calanus finmarchicus, which they consume in large numbers by ram filter feeding. The coastal waters where these whales forage are turbid, but they successfully locate copepod swarms during the day at depths exceeding 100 m, where light is very dim and copepod patches may be difficult to see. Using models of E. glacialis visual sensitivity together with measurements of light in waters near Cape Cod where they feed and of light attenuation by living copepods in seawater, we evaluated the potential for visual foraging by these whales. Our results suggest that vision may be useful for finding copepod patches, particularly if E. glacialis searches overhead for silhouetted masses or layers of copepods. This should permit the whales to locate C. finmarchicus visually throughout most daylight hours at depths throughout their foraging range. Looking laterally, the whales might also be able to see copepod patches at short range near the surface.
    Description: This work is based on research supported by the Air Force Office of Scientific Research, under grant no. FA9550-12-1-0321. Support for field observations was provided by the Woods Hole Oceanographic Institution and by the National Oceanic and Atmospheric Administration (NOAA) Northeast Fisheries Science Center.
    Keywords: Right whale ; Visual sensitivity ; Contrast vision ; Environmental radiometry
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...