Dry weight and chemical composition (CHN) in relation to population density of cultivatedTisbe holothuriae (Copepoda, Harpacticoida)

Qian, Zhang; Uhlig, G.

doi:10.1007/bf02430360

Cited by 8 publications

(4 citation statements)

References 9 publications

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“…The additional negative effects of density on population growth rate of T. battagliai could occur because of interference competition influencing reproductive performance, survival or somatic growth or foraging efficiency. Crowding is known to increase swimming activity in T. battagliai, with an associated increase in energy costs (Gaudy & Guerin 1982) possibly as a result of antagonism between larvae (Brand et al 1985); crowding is also known to reduce reproductive output and depress larval viability (Fava & Crotti 1979;Zhang & Uhlig 1993) and to influence the sex ratio from a female bias at low density Phil. Trans.…”

Section: (B) Results and Discussionmentioning

confidence: 99%

Population growth rate and its determinants: an overview

Sibly

Hone

2002

Phil. Trans. R. Soc. Lond. B

442

266

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We argue that population growth rate is the key unifying variable linking the various facets of population ecology. The importance of population growth rate lies partly in its central role in forecasting future population trends; indeed if the form of density dependence were constant and known, then the future population dynamics could to some degree be predicted. We argue that population growth rate is also central to our understanding of environmental stress: environmental stressors should be defined as factors which when first applied to a population reduce population growth rate. The joint action of such stressors determines an organism's ecological niche, which should be defined as the set of environmental conditions where population growth rate is greater than zero (where population growth rate = r = log(e)(N(t+1)/N(t))). While environmental stressors have negative effects on population growth rate, the same is true of population density, the case of negative linear effects corresponding to the well-known logistic equation. Following Sinclair, we recognize population regulation as occurring when population growth rate is negatively density dependent. Surprisingly, given its fundamental importance in population ecology, only 25 studies were discovered in the literature in which population growth rate has been plotted against population density. In 12 of these the effects of density were linear; in all but two of the remainder the relationship was concave viewed from above. Alternative approaches to establishing the determinants of population growth rate are reviewed, paying special attention to the demographic and mechanistic approaches. The effects of population density on population growth rate may act through their effects on food availability and associated effects on somatic growth, fecundity and survival, according to a 'numerical response', the evidence for which is briefly reviewed. Alternatively, there may be effects on population growth rate of population density in addition to those that arise through the partitioning of food between competitors; this is 'interference competition'. The distinction is illustrated using a replicated laboratory experiment on a marine copepod, Tisbe battagliae. Application of these approaches in conservation biology, ecotoxicology and human demography is briefly considered. We conclude that population regulation, density dependence, resource and interference competition, the effects of environmental stress and the form of the ecological niche, are all best defined and analysed in terms of population growth rate.

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Section: (B) Results and Discussionmentioning

confidence: 99%

Population growth rate and its determinants: an overview

Sibly

Hone

2002

Phil. Trans. R. Soc. Lond. B

442

266

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“…However, the SNR was 13 for two copepod egg sacs which is much lower than what was observed for one D. magna parthenogenetic egg in previous work. 25 This is because copepod egg sacs are less dense and have an additional shell/membrane, 45 providing a much lower dry mass (∼2 μg per sack) 41 compared to a D. magna parthenogenetic egg. 46 To our knowledge, this is the first HMQC obtained from copepod egg sacs and demonstrates that using laser-machined microcoils has considerable potential for biological analysis.…”

Section: Analytical Chemistrymentioning

confidence: 99%

“…The SNR and SNR per mg of algae are also shown. The solenoid was also used to analyze two13 C-labeled copepod egg sacs ((green arrows), a combined mass of 4 μg),41 which were found to contain mostly triglycerides, phosphatidylcholine, and some carbohydrates (C) 42,43. A microscope photograph for each microcoil is shown in the top-left corner of each HMQC.G…”

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confidence: 99%

Exploration of Materials for Three-Dimensional NMR Microcoil Production via CNC Micromilling and Laser Etching

Moxley-Paquette,

Pellizzari,

Lane

et al. 2024

Anal. Chem.

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The excellent versatility of 5-axis computer numerical control (CNC) micromilling has led to its application for prototyping NMR microcoils tailored to mass-limited samples (reducing development time and cost). However, vibrations during 5-axis milling can hinder the creation of complex 3D volume microcoils (i.e., solenoids and saddle coils). To address these limitations, a high-resolution NSCNC ELARA 4-axis milling machine was developed with the extra precision required for making complex 3D volume microcoils. Upon investigating the performance of resonators made with various copper-coated dielectrics, resonators with poly(methyl methacrylate) (PMMA) provided the best SNR/line shape. Thus, complex 1.7 mm microcoil designs were machined from Cu-coated PMMA. A milled 6.4 mm solenoid also provided 6.6× the total carbon signal for a 13 C-labeled broccoli seed compared to a commercial inverse 5 mm NMR probe (demonstrating potential for larger coil designs). However, the manufacture of coils <1.7 mm with copper-coated PMMA rods was challenging as ∼0.5 mm of remaining PMMA was needed to retain their structural integrity. To manufacture smaller microcoils, both a solenoid and saddle coil (both with 1 mm O.D., 0.1 mm thick walls) were etched from Cu-coated glass capillaries using a UV picosecond laser that was mounted onto an NSCNC 5-axis MiRA7L. Both resonators showed excellent signal and identified a wide range of metabolites in a 13 C-labeled algae extract, while the solenoid was further tested on two copepod egg sacs (∼4 μg of total sample). In summary, the flexibility to prototype complex microcoils in-house allows laboratories to tailor microcoils to specific mass-limited samples while avoiding the costs of cleanrooms.

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“…The harpacticoid copepod Tisbe holothuriae was one of the species receiving much attention. Being a species tolerating water quality characteristic of high‐density production systems, T. holothuriae was used in a range of production experiments focusing on intensive mass culture (Zhang & Uhlig 1993a, b; Støttrup & Norsker 1997).…”

Section: Introductionmentioning

confidence: 99%

Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepodTisbe holothuriae

Steenfeldt

Nielsen

2009

Aquaculture Research

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Copepods are well known to be the optimal live feed for most species of marine ¢sh larvae. Still copepods are rarely used in marine hatcheries worldwide. Lack of e⁄cient production techniques are among the reasons for this. Consequently, Artemia and rotifers are utilized in commercial settings. One problem in intensive production of copepods is contamination with rotifers. Rotifers have higher growth rates than copepods and consequently will compete out the copepods when accidentally introduced to the copepod production systems. Once contamination has occurred, the only cure has been to shut down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers.We tested £ubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L À 1 . There was no signi¢cant e¡ect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L À 1 £ubendazole. We conclude that £ubendazole is an e¡ective drug for control of B. plicatilis inT. holothuriae batch cultures.

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Dry weight and chemical composition (CHN) in relation to population density of cultivatedTisbe holothuriae (Copepoda, Harpacticoida)

Cited by 8 publications

References 9 publications

Population growth rate and its determinants: an overview

Population growth rate and its determinants: an overview

Exploration of Materials for Three-Dimensional NMR Microcoil Production via CNC Micromilling and Laser Etching

Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepodTisbe holothuriae

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