Nucleic acid levels in copepods: dynamic response to phytoplankton blooms in the northern Baltic proper

Gorokhova, Elena; Edlund, Anna; Hajdu, Susanna; Zhivotova, E. N.

doi:10.3354/meps07100

Cited by 10 publications

(5 citation statements)

References 44 publications

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“…The average RNA:DNA ratio of 10.30 ± 4.35 reported for E. affinis in our study is about 3 times higher than the maximal value of ~3.5 measured for the same species in the northern Baltic proper during the spring phytoplankton bloom (Gorokhova et al 2007). Yet, our RNA:DNA average value is in fairly good agreement with a previous study reporting RNA:DNA ratio for other calanoid species under optimal nutritional and growth conditions.…”

Section: Rna:dna Ratio and Growth Condition Of Eurytemora Affiniscontrasting

confidence: 62%

“…In our study, the RNA:DNA ratio was significantly correlated to RNA concentration (r 2 = 0.61, p < 0.01) but not to that of DNA (p > 0.05), and the size of the copepods collected in our study was relatively constant (see 'Materials and methods'). Together, these results suggest that the variability in RNA:DNA ratio was likely related to variable growth conditions of the population of E. affinis across the St. Lawrence ETZ.The average RNA:DNA ratio of 10.30 ± 4.35 reported for E. affinis in our study is about 3 times higher than the maximal value of ~3.5 measured for the same species in the northern Baltic proper during the spring phytoplankton bloom (Gorokhova et al 2007). Yet, our RNA:DNA average value is in fairly good agreement with a previous study reporting RNA:DNA ratio for other calanoid species under optimal nutritional and growth conditions.…”

supporting

confidence: 39%

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Relating RNA:DNA ratio in Eurytemora affinis to seston fatty acids in a highly dynamic environment

Pommier¹,

Frenette

Glémet³

2010

Mar. Ecol. Prog. Ser.

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Nine stations were sampled across the St. Lawrence estuarine transition zone (ETZ) in summer 2006 in order to investigate the variability in Eurytemora affinis growth condition, as revealed by RNA:DNA ratios, and its relationship to the nutritional quality of seston, expressed in terms of fatty acid (FA) composition. The population of E. affinis in the St. Lawrence ETZ was under the influence of brackish waters, as well as fresh and saline waters landwards and seawards of the frontal mixing zone, respectively. The RNA:DNA ratio for E. affinis throughout the ETZ ranged from 2.14 to 23.01, with an average value of 10.30 ± 4.35. When compared with the previously reported RNA:DNA ratio for copepods under optimal growth conditions, our values suggest that the summertime population of E. affinis in the St. Lawrence ETZ was in good growth condition. The hydrodynamic imprint within the St. Lawrence ETZ translated into the distribution pattern of seston having various FA compositions. Freshwater seston was of better nutritional quality (i.e. richer in essential fatty acids) than that from brackish and more saline waters. However, this did not translate into a significantly different E. affinis RNA:DNA ratio between the 3 types of waters. Yet, the growth condition of E. affinis under the influence of fairly stable fresh waters was associated with the relative abundance of 20:5n3-rich seston advected from upstream despite the low contribution of chl a to total suspended particulate matter. Moreover, a comparison between seston and zooplankton FA composition revealed the potential trophic transfer of diatom-related FA from producers to consumers within fresh waters. No such correlations were evidenced within the most dynamic parts of the ETZ (brackish and more saline waters) where the relationship between E. affinis growth condition and seston quality was likely constrained by a spatial-temporal decoupling between seston and zooplankton.KEY WORDS: Eurytemora affinis · RNA:DNA ratio · Fatty acids · Estuarine transition zone · St. Lawrence River Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 400: [143][144][145][146][147][148][149][150][151][152][153][154] 2010 The zooplankton assemblage in the St. Lawrence ETZ is dominated by Eurytemora affinis. This calanoid copepod plays an important role in the trophic dynamics of the St. Lawrence upper estuary where it feeds on phytoplankton (Winkler et al. 2003), mainly freshwater species advected from upstream (Lapierre & Frenette 2008), as well as on aggregates and attached bacteria (Zimmermann-Timm 2002, Martineau et al. 2004). E. affinis is amongst the major prey items for anadromous fish larvae (Winkler et al. 2003, Barnard et al. 2006, such as Microgadus tomcod and Osmerus mordax, which may colonize downstream environments later in their ontogenic cycle. Given its key trophic position within the St. Lawrence ETZ, E. affinis may therefore be considered an important regulator of the biological connectivity between the St...

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Section: Rna:dna Ratio and Growth Condition Of Eurytemora Affiniscontrasting

confidence: 62%

supporting

confidence: 39%

Relating RNA:DNA ratio in Eurytemora affinis to seston fatty acids in a highly dynamic environment

Pommier¹,

Frenette

Glémet³

2010

Mar. Ecol. Prog. Ser.

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“…S1). As a biochemical proxy of zooplankton growth we used RNA : DNA ratio, a proxy for protein synthetic capacity (Sterner and Elser , Gorokhova et al ). The RNA and DNA were measured in the RNA later‐ preserved zooplankton.…”

Section: Methodsmentioning

confidence: 99%

Grazing on cyanobacteria and transfer of diazotrophic nitrogen to zooplankton in the Baltic Sea

Motwani

Duberg

Svedén

et al. 2017

Limnology & Oceanography

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Nitrogen‐fixing cyanobacteria (NFC) are important primary producers in many freshwater and marine systems, including the Baltic Sea. In this system, NFC circumvent summer nitrogen limitation, while also generating a supply of novel combined nitrogen and thus supporting food webs. Using field observations on zooplankton and phytoplankton development during a growth season in the northern Baltic Proper, we show that cyanobacterial nitrogen is assimilated and transferred to zooplankton via both direct grazing on NFC and indirectly through grazing on picoplankton, such as picocyanobacteria. The key findings supporting these conclusions are: (1) all zooplankton grazers were found to ingest NFC (Nodularia spumigena) and picocyanobacteria (Synechococcus spp.); (2) ingestion of both NFC and picocyanobacteria measured by quantitative polymerase chain reaction analysis was highly correlated with ambient stocks of the respective cyanobacteria; (3) consumption of NFC and picocyanobacteria translated into decreased δ15N signature of zooplankton indicative of diazotrophic nitrogen input; (4) growth and reproduction indices in zooplankters were significantly positively related to NFC and picocyanobacteria; and (5) zooplankton biomass was positively related to the increasing nitrogen content of particulate organic matter (POM < 10 μm) and was highest at low POM δ15N values; the latter reflected overlap in zooplankton production and diazotroph seasonal dynamics. These findings provide empirical evidence that both NFC and picoplankton are readily ingested and assimilated by zooplankton, albeit with differential effects on growth and recruitment.

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“…This is a complex process in metabolism involving the interaction of nucleic acids and proteins (Yebra et al, 2011). It has been studied that growth is correlated with protein content in the consumed feed (Gorochova, 2003;Gorokhova et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Organic Feed Enrichment Effects toward Growth Performance and Egg Production of <i>Oithona similis</i>

et al. 2020

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The optimum condition of culture media and feed diets which fit the necessities of Oithona similis life (ecophysiological) is very important for it to grow and develop in its maximum. The enrichment of O. similis feed can be done by adding fermented organic feed. Providing organic feed with optimum protein content is necessary to support the growth process and reproduction of O. similis. Osmoregulation process of water organism which is influenced by media salinity is related to bioenergetics process as the effort to use feed energy for the growth. This research aimed to examine the effect of different organic feed protein content and to determine the optimum point which may result in the best growth and egg production of O. similis in the optimum condition of culture media. The study used an experimental method with a completely random design consisting of 4 treatments and 4 repetitions each, i.e. O. similis culture with A. 25%; B. 30%; C. 35%; and D. 40% organic feed protein content. The results showed that the difference of protein content in organic feed affects the growth and production of O. similis eggs. The optimum point of protein content in the fermented organic feed is on protein content B, i.e. 30%, which resulted in the best growth performance (70.44 ± 0.43 ind.mL-1 total density, 0.213 ± 0.001.day-1 population growth rate, and 27.38 ± 0.48 eggs.ind-1 egg production. (ttujuan dan pembahasan harus past tense), Tujuan di abstrak minimal harus menggambarkan atau sama denga tujuan di pendahuluan)Keywords: enrichment, Oithona similis, organic feed, protein, reproduction

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Nucleic acid levels in copepods: dynamic response to phytoplankton blooms in the northern Baltic proper

Cited by 10 publications

References 44 publications

Relating RNA:DNA ratio in Eurytemora affinis to seston fatty acids in a highly dynamic environment

Relating RNA:DNA ratio in Eurytemora affinis to seston fatty acids in a highly dynamic environment

Grazing on cyanobacteria and transfer of diazotrophic nitrogen to zooplankton in the Baltic Sea

Organic Feed Enrichment Effects toward Growth Performance and Egg Production of <i>Oithona similis</i>

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