Lipid content in overwintering <i>Calanus finmarchicus</i> across the Subpolar Eastern North Atlantic Ocean

Jónasdóttir, Sigrún; Wilson, Robert J.; Gíslason, Ástþór; Heath, Michael R.

doi:10.1002/lno.11167

Cited by 37 publications

(43 citation statements)

References 56 publications

(124 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the company has found that extraction achieved in the laboratory by the use of solvents without heat vs. the industrial production with heat resulted in similar lipid composition (Calanus AS unpublished data). Furthermore, the chemical composition of the extracted oil, being rich in wax ester content (94% of neutral lipids) with a high level of unsaturation in the fatty acids and fatty alcohols (Table ), is similar to what has been reported for wild calanoid copepods in different areas (Yayanos et al ; Sargent and Falk‐Petersen ; Jónasdóttir et al ), suggesting that it is representative of in situ animals.…”

Section: Use Materials and Proceduressupporting

confidence: 78%

Accounting for seasonal and composition‐related variability in acoustic material properties in estimating copepod and krill target strength

Sakınan

Lawson

Wiebe

et al. 2019

Limnology & Ocean Methods

View full text Add to dashboard Cite

Estimation of abundance or biomass, using acoustic techniques requires knowledge of the frequency dependent acoustic backscatter characteristics, or target strength, of organisms. Target strength of zooplankton is typically estimated from physics‐based models that involve multiple parameters, notably including the acoustic material properties (i.e., the contrasts in density and sound speed between the animal and surrounding seawater). In this work, variability in the acoustic material properties of two zooplankton species in the Gulf of Maine, the copepod (Calanus finmarchicus) and krill (Meganyctiphanes norvegica), was investigated relative to changing season as well as, for the copepod, temperature and depth. Increases in the density and sound speed contrasts of these species from fall to spring were observed. Target strength predictions based on these measurements varied between fall and spring by 2‐3 dB in krill. Measurements were also conducted on C. finmarchicus lipid extract at changing temperature and pressure. The density contrast of the extract varied negatively with temperature, while the sound speed contrast changed by more than 10 % over the temperature and pressure ranges that the organism expected to occupy. C. finmarchicus target strength predictions showed that the combined effect of temperature and pressure can be significant (more than 10 dB) due to the varying response of lipids. The large vertical migration ranges and lipid accumulation characteristics of these species (e.g., the diapause behaviour of Calanus copepods) suggest that it is necessary for seasonal and environmental variability in material properties to be taken into account to achieve reliable measurements.

show abstract

Section: Use Materials and Proceduressupporting

confidence: 78%

Accounting for seasonal and composition‐related variability in acoustic material properties in estimating copepod and krill target strength

Sakınan

Lawson

Wiebe

et al. 2019

Limnology & Ocean Methods

View full text Add to dashboard Cite

show abstract

“…In conclusion, N. flemingeri accumulates resources in a highly heterogeneous environment with a narrow 3-month window to store sufficient capital for diapause and reproduction (Mackas and Coyle, 2005;Coyle et al, 2019). Diapausing calanid copepods, including N. flemingeri females range in size and in their lipidsac volumes (Saito and Tsuda, 2000;Jónasdóttir et al, 2019). However, low mortality throughout the incubation period of 9.5 weeks suggests that N. flemingeri females even with fewer stored resources are able to complete the reproductive program albeit at lower fecundity.…”

Section: Discussionmentioning

confidence: 93%

Capital Breeding in a Diapausing Copepod: A Transcriptomics Analysis

et al. 2020

View full text Add to dashboard Cite

Capital breeders must balance the energetic requirements of cellular function and the cost of reproduction. The subarctic copepod Neocalanus flemingeri, a small planktonic crustacean, depends on a short annual phytoplankton bloom to acquire the energy needed to support a non-feeding adult female that enters a period of diapause prior to spawning 5 to 7 months later. After emergence from diapause, the reproductive program takes 2 months starting with germline development. In this study, the regulation of genes involved in energy utilization and cellular maintenance were investigated using RNA-Seq as females progressed from diapause to end-of-life. Hierarchical clustering of expression profiles from 61 individual females identified four major transitions in transcriptional profiles along a timeline spanning from diapause to spawning and postreproduction. The clusters were analyzed statistically for differential gene expression followed by functional analyses. The transition from diapause to post-diapause (early to mid-oogenesis) was characterized by the up-regulation of genes involved in cellular homeostasis, glycolysis and lipid catabolism. As females approached spawning genes involved in cellular homeostasis, like innate immunity became down-regulated. Genes involved in protein ubiquitination and programmed cell death became up-regulated as females started to spawn. Gene expression patterns suggest that energy allocation and utilization is highly dynamic in N. flemingeri during the progression of the reproductive period. Major changes in the expression of genes involved in cellular homeostasis, metabolic processes and autophagy were linked to stages of egg maturation. Changes in gene expression that marked the transition from diapause to post-diapause were similar to those reported in other arthropods that resume feeding after emergence from diapause. As egg maturation progressed, gene expression patterns indicate that resources became concentrated on provisioning eggs, while being diverted away from cellular homeostasis. The data suggest that in N. flemingeri genes are regulated such that organismal function and sources of energy are synchronized with stages of egg maturation to optimize the exploitation of finite resources. The existence of mechanisms that regulate fecundity to match the availability of stored resources could reduce reproductive failure in this species.

show abstract

“…Contrasting pelagic ecosystem functioning in eastern and western Baffin Bay revealed by trophic network modeling An attenuation of the carbon exported during passive sinking can occur due to the remineralization of organic detritus via bacterial degradation (e.g., Kellogg et al, 2011;Le Moigne et al, 2013). Zooplankton are also involved in an active transport of carbon, with very limited attenuation, below the sequestration depth (Visser et al, 2017;Jónasdóttir et al, 2019). The large copepods of the genus Calanus, dominating the Arctic Ocean (e.g., Auel and Hagen, 2002;Darnis et al, 2008), evolved their life-cycle strategy (Maps et al, 2014) in order to survive the winter.…”

Section: Research Articlementioning

confidence: 99%

Contrasting pelagic ecosystem functioning in eastern and western Baffin Bay revealed by trophic network modeling

et al. 2020

View full text Add to dashboard Cite

Baffin Bay, located at the Arctic Ocean's 'doorstep', is a heterogeneous environment where a warm and salty eastern current flows northwards in the opposite direction of a cold and relatively fresh Arctic current flowing along the west coast of the bay. This circulation affects the physical and biogeochemical environment on both sides of the bay. The phytoplanktonic species composition is driven by its environment and, in turn, shapes carbon transfer through the planktonic food web. This study aims at determining the effects of such contrasting environments on ecosystem structure and functioning and the consequences for the carbon cycle. Ecological indices calculated from food web flow values provide ecosystem properties that are not accessible by direct in situ measurement. From new biological data gathered during the Green Edge project, we built a planktonic food web model for each side of Baffin Bay, considering several biological processes involved in the carbon cycle, notably in the gravitational, lipid, and microbial carbon pumps. Missing flow values were estimated by linear inverse modeling. Calculated ecological network analysis indices revealed significant differences in the functioning of each ecosystem. The eastern Baffin Bay food web presents a more specialized food web that constrains carbon through specific and efficient pathways, leading to segregation of the microbial loop from the classical grazing chain. In contrast, the western food web showed redundant and shorter pathways that caused a higher carbon export, especially via lipid and microbial pumps, and thus promoted carbon sequestration. Moreover, indirect effects resulting from bottom-up and top-down control impacted pairwise relations between species differently and led to the dominance of mutualism in the eastern food web. These differences in pairwise relations affect the dynamics and evolution of each food web and thus might lead to contrasting responses to ongoing climate change.

show abstract

Lipid content in overwintering Calanus finmarchicus across the Subpolar Eastern North Atlantic Ocean

Cited by 37 publications

References 56 publications

Accounting for seasonal and composition‐related variability in acoustic material properties in estimating copepod and krill target strength

Accounting for seasonal and composition‐related variability in acoustic material properties in estimating copepod and krill target strength

Capital Breeding in a Diapausing Copepod: A Transcriptomics Analysis

Contrasting pelagic ecosystem functioning in eastern and western Baffin Bay revealed by trophic network modeling

Contact Info

Product

Resources

About