Abstract
The filter feeding blue tilapia, Tilapia aurea, was fed three different algae. Blue tilapia ingestion of two green algae, Chlamydomonas sp. and Ankistrodesmus falcatus and the filamentous blue-green alga, Anabaena flos-aquae, ranged from 21%–89% of the available cells. There were significant differences in the assimilation of algal carbon by the fish depending on the alga fed; A. flos-aquae was the easiest to assimilate (83%). The fish respired significantly less of the Chlamydomonas sp. ingested carbon (15%). The gross growth efficiency of fishes fed either green alga was not significantly different (22%–24%), but these efficiencies were significantly less than the gross growth efficiency of fish fed A. flos-aquae (46%). The carbon budgets for fish feeding on the green algae were similar to that constructed from the literature for a congener fed a mixed algae diet. However, the assimilation component of the budget for blue tilapia fed A. flos-aquae was 2 times greater than that of the literature budget.