Comparative Evaluation of the Effectiveness of some local Fabrics for Zooplankton Harvest

Abstract

A comparative evaluation of the effectiveness for zooplankton harvest for three local fabrics (a white poplin, 120\u3bcm; grey baft, 200\u3bcm; a nylon, 235\u3bcm) and an imported standard zooplankton net of mesh size 76\u3bcm were tested in this study. Mesh sizes and gauze constitution of the fabrics were determined with an ocular micrometer under a compound microscope. Filtration efficiency and clogging rates of the fabrics were also measured. All fabrics were effective in harvesting species of the copepods, the cladocerans and the large-sized rotifer, Asplanchna . The grey baft and the nylon net were not effective in harvesting the small-sized rotifer species like Keratella , Filinia and Trichocerca . All the fabrics effectively harvested Moina , an excellent freshwater cladoceran for fish larval-rearing. Clogging rate was found to be a function of gauze constitution, while filtration efficiency was an index of both gauze constitution and mesh size of fabrics. @ JASE