Clearance Rates Of Suspended Particulate Organic Carbon By Nile Tilapia With A Dual Pattern Of Filter Feeding

Abstract

The filter-feeding activity of Nile tilapia, Oreochromis niloticus L., was observed during a 24-h feeding cycle for five consecutive days. The feeding activity was high from afternoon to midnight, with a peak after dusk, and lowest from midnight to morning. The clearance rate of cyanobacte- ria dominated water was estimated during the low morning and high evening feeding periods. The tilapia cleared 34 mg C/l suspended particulate organic carbon in 4.5 h during the reduced morning period (beginning 07:00) and 45 mg C/l in 1 h during the peak evening period (begin- ning 20:30). Clearance rates of the cyanobacterial water were 13.4±1.2 l/kg fish/h in the morn- ing and 66±3.6 l/kg fish/h in the evening.