Date of Award

Summer 1983

Document Type


Degree Name

Master of Science (MS)



Committee Director

Anthony J. Provenzano

Committee Member

William Dunstan

Committee Member

John McConaugha

Committee Member

Terry Wade

Call Number for Print

Special Collections LD4331.O35 B36


It has been reported that the Java tilapia, Oreochromis mossambicus, displays hypersensitivity to a substance it produces when biomass levels in a flow-through culture system exceed 20 g/1, resulting in reduced growth and high mortality. Experiments on the growth of this species in small tanks were conducted in order to determine whether O. mossambicus produces a growth-inhibiting compound under crowded conditions. This species was successfully maintained at biomass levels of 38 g/1 and 57 g/1 with a total mortality of only 4.5%.

The Java tilapia can grow rapidly in small aquaria, as indicated by the data taken during Experiment I. Unfavorable conditions caused severe depression of growth in Experiment II and reduced rates of growth in Experiment III. Although the presence of a "crowding factor" could not be demonstrated satisfactorily in these experiments, general responses of O. mossarnbicus to crowding were similar to those observed in other aquatic animals and described in the literature. Further studies are required in order to establish the limits of stocking density in tanks that this species can tolerate.


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