A new radiotracer technique involving 14C and 51Cr, for estimating the assimilation efficiencies of aquatic, primary consumers Article Received: 03 January 1972 DOI:
Cite this article as: Calow, P. & Fletcher, C.R. Oecologia (1972) 9: 155. doi:10.1007/BF00345880 Summary
Gravimetric, radiotracer, and indicator methods currently available for estimating assimilation efficiencies, have been reviewed and their associated limitations have been discussed. It was concluded that the basic assumption implicit to gravimetric and indicator techniques, i.e. that all material contained within the faeces is derived from the food, does not generally hold. Radiotracer techniques are not based on this assumption but are time consuming. Consequently a new radiotracer technique analogous to indicator methods has been developed. In this technique the concentration of a non-absorbed indicator is expressed in terms of a radiotracer,
14C, which can be absorbed but which, at least initially, is only present in the food, rather than expressing it in terms of dry weight. 51Cr has been used as the nonabsorbed indicator.
Use of these two isotopes in conjunction not only enables a distinction to be made between faecal material derived from food, and that derived from metabolic secretions but also facilitates estimation of assimilation efficiences fromsmall samples of faeces only. The new technique requires simply, measurement of the ratio
14C: 51Cr in samples of both food and faeces.
The applicability of conditions necessary for operation of the new technique has been tested on two species of freshwater gastropod, one feeding on epilithic algae, the other on bacteria, and its effectiveness has been tested by reference to results obtained from another, more conventional method involving
14C only. References
Allen, E., Nelson, E. W.: On the artificial culture of marine plankton organisms. J. marine biol. Ass.
, 421–474 (1910).
Bowen, H. J. M.: Trace elements in biochemistry, 241 p. London-New York: Academic Press 1966.
Calow, P.: Studies on the natural diet of
Lymnaea pereger obtusa
(Kobelt) and its possible ecological implications. Proc. malac. Soc. Lond.
, 203–215 (1970).
Carriker, M. R.: Observations on the functioning of the alimentary system of the snail
Lymnaea stagnalis appressa
. Say. Biol. Bull. Woods Hole
, 88–111 (1946).
Chipman, W. A.: Some aspects of the accumulation of
Cr by marine organisms. Radioecological concentration processes, eds. B. Aberg and F. P. Hungate, p. 931–941. Oxford-London-Edinburgh-New York-Toronto-Sydney-Paris-Braunschweig: Pergamon Press 1966.
Conover, R. J.: Assimilation of organic matter by zooplankton. Limnol. Oceangr.
, 338–345 (1966).
Corbett, J. L., Greenhalgh, F. D., McDonald, I., Florence, E.: Excretion of chromium sesquioxide administered as a component of paper to sheep. Brit. J. Nutr.
, 289–299 (1960).
Fewkes, D. W.: The food requirements by weight of some British
(Heteroptera). Entomol. exp. appl.
, 231–237 (1960).
Fischer, Z.: Food selection and energy transformation in larvae of
(Odonata) in Asiatic waters. Verh. int. Verein. theor. angew. Limnol.
, 600–603 (1966).
Foster, R. F.: Enviromental behaviour of chromium and neptunium. Radioecology, eds. V. Schultz and A. W. Klement, Jr., p. 569–576. New York and Washington: Reinhold Publishing Corp. and The American Institute of Biological Sciences 1963.
Fruton, J. S., Simmonds, S.: General biochemistry, 1077 p. New York: Wiley 1959.
Hargrave, B. T.: The utilisation of benthic microflora by
(Amphipoda). J. Anim. Ecol.
, 421–437 (1970).
Hubbell, S. P., Sikora, A., Paris, O. H.: Radiotracer, gravimetric, and calorimetric studies of ingestion and assimilation ratios of an isopod. Hlth Phys.
, 1485–1501 (1965).
Johannes, R. E., Satomi, M.: Measuring organic matter retained by aquatic invertebrates. J. Fisheries Res. Bd. Can.
, 2467–2471 (1967).
Klekowski, R. Z., Shushkina, E. A.: Ernährung, Atmung, Wachstum und Energie-Umformung in
(Jurine). Verh. int. Verein. theor. angew. Limnol.
, 399–418 (1966).
Knight, B. C. J. G., Proom, H.: A comparative survey of the nutrition and physiology of mesophilic species in the genus Bacillus. J. gen. Microbiol.
, 508–538 (1950).
Lawton, J. H.: Feeding and food energy assimilation in larvae of the Damselfly,
(Sulz.) (Odonata; Zygoptera). J. Anim. Ecol.
, 669–689 (1970).
McGinnis, A. J., Kasting, R.: Chromic oxide indicator method for measuring food utilisation in a plant feeding insect. Science
, 1464–1465 (1964a).
McGinnis, A. J., Kasting, R.: Digestion in insects, colorimetric analysis of chromic oxide used to study food utilisation by phytophagous insects. J. agric. Fd. Chem.
, 259–262 (1964b).
McKenzie, R. D., Anwar, R. A., Byerrum, R. U., Hoppert, C. A.: Absorption and distribution of
Cr in the albino rat. Arch. Biochem.
, 200–205 (1959).
Millipore Filter Corporation: Techniques for exfoliative cytology (ADM-50), 18p. (1964).
Monakov, A. V., Soroin, Yu. I.: Quantitative data on the feeding of Daphnia. Trud. Inst. Bil. Vodokhr.
, 251–261 (1961).
Odum, E. P., Keunzler, E. J.: Experimental isolation of food chains in an old field system with use of
P. Radioecology, eds. V. Schultz and A. W. Klement, Jr., p. 113–125. New York and Washington: Reinhold Publishing Corp. and The American Institute of Biological Sciences 1963.
Petrusewicz, K.: Concepts in studies on the secondary productivity of terrestrial ecosystems. Secondary productivity of terrestrial ecosystems, vol. 1, ed. K. Petrusewicz, p. 17–49. Warsaw: Panstwavi Wydownicwo Naukowi 1967a.
Petrusewicz, K.: Suggested list of more important concepts in productivity studies (definitions and symbols). Secondary productivity in terrestrial ecosystems, vol. 1, ed. K. Petrusewicz, p. 51–58. Warsaw: Panstwavi Wydownico Naukowi 1967b.
Phillipson, J.: A contribution to the feeding biology of
(F) (Phalangida). J. Anim. Ecol.
, 35–43 (1960a).
Phillipson, J.: The food consumption of different instars of
(F) (Phalangida) under natural conditions. J. Anim. Ecol.
, 299–301 (1960b).
Saunders, G. W.: Some aspects of feeding in zooplankton. Eutrophication, Chairman G. A. Rohlich, p. 556–573. Washington: National Academy of Sciences 1969.
Schwarz, K., Mertz, W.: Chromium 111 and the glucose tolerance factor. Arch. Biochem.
, 292–295 (1959).
Shushkina, E. A., Anisimov, S. I., Klekowski, R. Z.: Calculation of production efficiency in plankton copepods. Polskie Arch. Hydrobiol.
, 251–261 (1968).
Smith, D. S.: Utilisation of food plants by the migratory grasshopper,
(Walker) (Orthoptera: Acrididae) with some observations on the nutritional value of plants. Ann. ent. Soc. Amer.
, 674–680 (1959).
Strickland, J. D. H.: Production of organic matter in the primary stages of the marine food chain. Chemical oceanography, vol. 1, eds. J. P. Riley and S. Skirrow, p. 433–473. London-New York: Academic Press 1965.
Timofeyeva-Resovskaya, Ye. A.: Distribution of radioisotopes in the main components of freshwater bodies. Tr. inst. biol. Akad. Nauk. S. S. S. R.
, 1–78 (1963).
Utley, P. R., Boling, J. A., Bradley, N. W., Tucker, R. E.: Recovery of radioactive chromic oxide from the bovine gastrointestinal tract. J. Nutr.
, 1227–1232 (1970).
Wallen, D. G., Geen, G. H.: Loss of radioactivity during storage of
C-labelled phytoplankton on membrane filters. J. Fisheries Res. Bd. Can.
, 2219–2224 (1968).
Whittam, R., Wheeler, K. P.: Transport across cell membranes. Ann. Rev. Physiol.
, 21–60 (1970).