DefinePK

Abstract

Response of five levels of nitrogen, viz. 0.10, 0.13, 0.16, 0.19 and 0.22 g N/100 g fish daily, from broiler droppings towards planktonic productivity of major carps rearing ponds. Six genera of Chlorophyceae, viz. Chlamydomonas, Closterium, Microspora, ❑edogonium, Pandorina, Spirogyra; two genera of Chrysophyceae including Botryocaccus, Synura; and three genera of Bacillariophyceae (Cyclotella, Cymbella and Navicula) were recorded during different months in six treatments. As regards Dinophyceae and Euglenophyceae, the genera observed were Peridinium and Euglena respectively. Myxophyceae included the genera Anabaena, Microcystis and Oscillatoria. Zooplankton represented by ciliates (Protozoans) and 10 other genera in all treatments except under 0.16 g level of nitrogen. However, the increase beyond 0.16 g nitrogen level showed gradual decrease in zooplankton productivity upto 0.22 g nitrogen level. The correlation coefficients between phytoplankton and zooplankton productivities, under all the treatments, were positive and significant.