Surface Area of the Euphausiid Thysanöessa raschii and Its Relation to Body Length, Weight, and Respiration

1977 ◽  
Vol 34 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Gareth C. H. Harding

A method is described for estimating the surface area of marine crustaceans. The external surface area of the euphausiid Thysanöessa raschii (M. Sars) is proportional to length2.4, dry weight0.95, and wet weight0.84. Oxygen consumption is proportional to wet weight0.82, which indicates that respiration should be proportional to respiratory surface area. The implications of this finding regarding the relations of metabolic rate, size, and surface area are discussed in a broader framework by comparing them with similar studies on vertebrates and other invertebrates.

1997 ◽  
Vol 45 (1-2) ◽  
pp. 01-10 ◽  
Author(s):  
Phan Van Ngan ◽  
Vicente Gomes ◽  
Paulo S. M. Carvalho ◽  
Maria José de A. C. R. Passos

Routine oxygen consumption of krill was investigated as a general measure of its metabolism and assesses the effects of body size, temperature and starvation on the metabolism. No significant difference in whole animal consllmption was detected after 1,3,5 and 7 days of starvation. The response of metabolism of krill to temperature shows a zone of independence, from 0 to 1°C in which the temperature exerts no effect on metabolism. From 1 to 4°C the metabolism increases rapidly in function of temperature. There was a general increase in oxygen consumption with increasing body wet weight. The equation 'between consumption and wet weight is given by Log Q02 = 2.061+ 0.987xLogW, with r = 0.86. The slope of the regression line b=0.987 is less than unity, indicating that oxygen consllmption per unit weight is greater for the smaller than for the larger krill. Average metabolic rate at O°C of 164 krill is 733.24 l, µlO2g(dry wt)-1h-1. The metabolic rate is of 1129.67 J- µlO2g(dry wt)-1h-1 for small krill (13-19 mg dry weight) and 636.16 J- µlO2g(dry wt)-1h-1 for larger animais (160-169 mg dry weight). The metabülism ofkrill is shown to be related to period of adaptation and types of respirometer. Prolonged adaptation period showed adverse effect on metabolism and average oxygen consumption is almost three times higher in respirometers with stirring device than in simple sealed chambers.


1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.


2015 ◽  
Vol 66 (10) ◽  
pp. 857 ◽  
Author(s):  
James Prescott ◽  
Shijie Zhou ◽  
Andhika P. Prasetyo

Tropical sea cucumbers are commonly exploited by small-scale, poorly managed fisheries. A fundamental problem in managing sea cucumber fisheries is the lack of basic knowledge of important life history characteristics for most species. As a result of plastic body dimensions, biological research on this group of animals becomes exceptionally challenging. To improve our understanding of essential biological parameters, we conducted a study to investigate correlations among various body measurements. We analysed a total of 18 sea cucumber species and more than 6600 individuals collected at Scott Reef in the Timor Sea, north-west Australia. We used hierarchical Bayesian errors-in-variables models to specifically take into account measurement errors that are obviously unavoidable. The measures included three types of weights (wet weight, gutted weight and dry weight) and two body dimensions (length and width). The modelling reveals that using both body length and width as independent variables, wet weight increases approximately linearly with body length, but is a power function (~1.6) of body width, although variability exists among species. Dry weight tends to increase more slowly with body length, but has a similar power function of body width. Linear relationships are established between the three types of weights. On average, ~11% of a live specimen and ~16% of a gutted specimen is processed to the commercially traded dry body wall. Our results can be applied to sea cucumbers in other areas and can be useful for data standardisation and size-based fisheries management.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rosemary Kate Steinberg ◽  
Emma L. Johnston ◽  
Teresa Bednarek ◽  
Katherine A. Dafforn ◽  
Tracy D. Ainsworth

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.


2017 ◽  
Vol 64 (3-4) ◽  
pp. 155-162
Author(s):  
Aleksandra Gorączko ◽  
Andrzej Olchawa

AbstractThe paper presents results of a study on the amount of water associated with the solid phase of the clay water system at the plastic limit. Two model monomineral clays, namely kaolinite, and montmorillonite, were used in the study. The latter was obtained by gravitational sedimentation of Na-bentonite (Wyoming).The calculated mean number of water molecule layers on the external surface of montmorillonite was 14.4, and water in interlayer spaces constituted 0.3 of the water mass at the plastic limit.The number of water layers on the external surface of kaolinite particles was 63, which was related to the higher density of the surface electrical charge of kaolinite compared to that of montmorillonite.The calculations were made on the basis of the external surface area of clays and the basal spacing at the plastic limit measured by an X-ray diffraction test. The external surface area of clays was estimated by measuring sorption at a relative humidity p/p0 = 0.5.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 185 ◽  
Author(s):  
Guido Giammaria ◽  
Gerard van Rooij ◽  
Leon Lefferts

The goal of this study is to develop a method to distinguish between plasma chemistry and thermal effects in a Dielectric Barrier Discharge nonequilibrium plasma containing a packed bed of porous particles. Decomposition of CaCO3 in Ar plasma is used as a model reaction and CaCO3 samples were prepared with different external surface area, via the particle size, as well as with different internal surface area, via pore morphology. Also, the effect of the CO2 in gas phase on the formation of products during plasma enhanced decomposition is measured. The internal surface area is not exposed to plasma and relates to thermal effect only, whereas both plasma and thermal effects occur at the external surface area. Decomposition rates were in our case found to be influenced by internal surface changes only and thermal decomposition is concluded to dominate. This is further supported by the slow response in the CO2 concentration at a timescale of typically 1 minute upon changes in discharge power. The thermal effect is estimated based on the kinetics of the CaCO3 decomposition, resulting in a temperature increase within 80 °C for plasma power from 0 to 6 W. In contrast, CO2 dissociation to CO and O2 is controlled by plasma chemistry as this reaction is thermodynamically impossible without plasma, in agreement with fast response within a few seconds of the CO concentration when changing plasma power. CO forms exclusively via consecutive dissociation of CO2 in the gas phase and not directly from CaCO3. In ongoing work, this methodology is used to distinguish between thermal effects and plasma–chemical effects in more reactive plasma, containing, e.g., H2.


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