In estimating the production rate, all characteristics related to 

 production, weight and metabolism are expressed in common units of 

 measurement, preferably in units of energy--calories. This brings up 

 the need to determine the energy equivalents of body mass and calorie 

 content of the basic elements of the planktonic community. The 

 energetic approach to the study of communities permits one to ignore, to 

 a certain extent, their species composition, but in return it is very 

 exacting in regard to information on their trophic and spatial 

 structure. 



The results of determination of the energy equivalents of body mass 

 Wg (cal/indiv.) as a function of length % (mm) for abundant planktonic 

 animals in the tropical Pacific (Shushkina, Sokolova, 1972), which can 

 be used for production estimates, are shown in Figure 23. Using these 

 regressions Wq[i) and knowing the mean length of animals of a given 

 taxon, we can determine the mean body weight in calories Wg. 



It is usually thought that planktonic animals in the higher 

 latitudes, due to their higher content of fat, also have a higher 

 caloric equivalent. However, comparison of the caloric equivalent of 

 mysids in the tropical regions of the Pacific, the Black Sea and the Sea 

 of Japan, (Fig. 24a) and chaetognaths in the same tropical regions, the 

 North Atlantic and Sea of Japan (Fig. 24b) showed no significant 

 difference, although it is quite probable that for other species of 

 zooplankton, i.e., copepoda, the differences in calorie content would be 

 greater. 



The regression Wg(£) for tropical animals of various taxonomic 

 groups is used to calculate the mean caloric equivalent (Kcal/mg wet 

 mass). The wet mass of animals of the groups studied was usually 

 determined by weighing, or from the dimensions of the body, using 

 nomograms, or empirical equations. The mean caloric equivalents thus 

 calculated for tropical phytoplankton, zooplankton, and bacteria 

 (Sushchenya, 1969; Troitskiy, Sorokin, 1967; Sorokin, 1971) are 

 presented in Table 13. 



Rate (R) and intensity (R/W) of metabolism of planktonic animals, 

 usually determined on the basis of the rate of consumption of oxygen, 

 are necessary for an estimation of the rate of production of 

 zooplankton, the flow of energy through a planktonic community and the 

 succession characteristics of pelagic ecosystems. 



Measurement of metabolic rates in marine and fresh-water animals 

 has been the subject of a large number of reports (reviews: Sushchenya, 

 1969, 1972). For marine zooplankton of various regions of the ocean, 

 rather extensive material has been obtained by the expeditions of the 

 Institute of Oceanology (Shushkina, Vilenkin, 1971; Shushkina, 1972; 

 Kukina, Chistov, 1972; Shushkina, Pavlova, 1973; Pavlova, 1973; 

 Kuz'micheva, Kukina, 1974; Klyashtorin, Kuz'micheva, 1975; Klekovskiy et 

 al., 1975; Pasternak, 1976; Musaeva, Vitek, 1975). It has been 

 suggested that the values of metabolic rates obtained in these 

 experiments are significantly low due to the limited movement of the 

 animals in the closed experimental bottle (Gruzov, 1972; Pavlova, 1973, 



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