|Etude de la nutrition, du régime et du rythme alimentaire du zooplankton dans les conditions naturelles, par la mesure des activités enzymatiques digestives = Study of the nutrition, the feeding regime and rhytm of the zooplankton under the natural conditions, through measurement of the digestive enzymatic activities|
Boucher, J.; Laurec, A.; Samain, J.-F.; Smith, S.L. (1976). Etude de la nutrition, du régime et du rythme alimentaire du zooplankton dans les conditions naturelles, par la mesure des activités enzymatiques digestives = Study of the nutrition, the feeding regime and rhytm of the zooplankton under the natural conditions, through measurement of the digestive enzymatic activities, in: Persoone, G. et al. (Ed.) Proceedings of the 10th European Symposium on Marine Biology, Ostend, Belgium, Sept. 17-23, 1975: 2. Population dynamics of marine organisms in relation with nutrient cycling in shallow waters. pp. 85-110
In: Persoone, G.; Jaspers, E. (Ed.) (1976). Proceedings of the 10th European Symposium on Marine Biology, Ostend, Belgium, Sept. 17-23, 1975: 2. Population dynamics of marine organisms in relation with nutrient cycling in shallow waters. IZWO/Universa Press: Wetteren. ISBN 90-6281-002-0. 712 pp., more
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- Boucher, J.
- Laurec, A.
- Samain, J.-F.
- Smith, S.L.
The amylase and trypsin activity of the most important zooplankton species has been measured in the upwelling zone of the Spanish Sahara during the "Gibraltar ecophysiological cruise" of the oceanographic vessel Jean Charcot. The analysis of the results was carried out for the double purpose of demonstrating the regulation by the nutrition of the activities of digestive enzymes and utilizing these results to study the feeding behavior under the natural environmental conditions of an ecosystem. With regard to its biological significance, the influence of the quality and quantity of food available has been demonstrated by a bouble experimental approach followed by a statistical one. Significant correlations were found between the specific amylase activity and the rates of ingestion and assimilation. An adaptation of amylase- and trypsin activity to the quantity and the quality of food available had been shown. This adaptation allows the organisms to maintain an optimum digestive efficiency. The statistical analysis of the in situ results shows the relationship between the digestive enzymatic activities and certain characteristics of the food (particles) available. The dimension of the particles and their chemical composition seem to be preponderant. The alimentary regime and rhythm are described from the ecological point of view. The regime was analysed for each of the eight species of copepods and the cladoceran studied. From the characteristics of the food ingested and the respective variations in the analyse and trypsin, which do not seem to be correlated, one can conclude the nature of the food ingested. The species studied appear to be omnivorous with carnivorous tendencies for Oocaea sp. and Podon intermedius, and herbivorous for Calanoides carinatus, Acartia clausi and Pleuromamma gracilis. A feeding rhythm which is regulated by external factors (trophic conditions) was demonstrated. The constancy of its periodicity with respect to the variation of the external conditions, as shown by the repetition of the measurements in, an oceanic zone 50 miles wide, forces one to also admit the existence of internal factors. It is a nycthemeral feeding rhythm.