Determination of the Ciliates' Individual Mass by the Improved “Volumes Ratio” Method

Abstract

Summary:The main methods of estimating the mean volume of ciliates are given:-cell-shape comparison to a simple geometrical figure, -direct determination, -models method.The last is more precise and its simplified variant allows us to computerize the procedure of calciilation the mean cell volume (mass).Correct estiniatibn of biomass, production and destruction of organic matter by hydrobionts are an extremely important problem in Hydrobiology. It depends on the precision of the determination of the individual's mean mass. Therefore, the consideration of the authors concentrates on the problem.Without colorimetry (SOHOLANDER et al.), all methods are based on the calculation of a mean cell volume and its density. The density of Protozoa is estimated a t 1.02 ... Frequently used are nomograms that give its volume from the data on a shape, cut form and size of the body (CHISLENKO). These methods are best applied to geometrical regular cells. The results are similar with the data of the direct determination (TROIT-SKY and SOROKIN). However, some ciliates are nonideal in shape and the use of the above mentioned methods may produce mistakes (KLEKOWSKI and TUMANTSEVA).2. Direct determination of the cell volume. The cell volume is measured by squeezing the cell between two glass surfaces spaced at a known distance and tracing the surface contour. The known distance is prepared by platinum filaments of a known diameter.

Evaluation of three methods for biomass estimation in small invertebrates, using three large disparate parasite species as model organisms

“…Comparing the indirect method 1 (modified from) 47 with 2, both require estimation of body thickness and yielded similar results. Both approaches are time- and cost-effective and easy to apply in most situations.…”

“…In particular, our method for estimating biomass from images seems more time- and cost-effective than previous approaches, catering for the growing need of obtaining reliable estimates of invertebrate biomass 48 . We validated the shaping methodology originally described for unicellular ciliates 47 to be generally applied to small invertebrates. This clay shaping-based method may be particularly valuable for organisms with complex morphology, although with the cost of time and skills investment, that may render this approach only useful for model species.…”

“…We adapted the method initially proposed by 47 to determine the individual mass of ciliates. We modelled with commercial air-drying clay the body of the selected specimens of C .…”