Effect of Iron on the Growth Rate of Fishes

Abstract

To determine the nutritional requirment for iron in fish growth, the effect of daily addition of supplemental ferrous sulfate on the growth of Xiphophorus helleri and Xiphophorus maculatus (the swordtail and the platyfish) was measured by determination of weight gain and hematocrit levels. Both variables increased as a result of the added iron. The effectiveness of the treatment diminished as sexual maturity was approached. Treatment with ferrous sulfate led to an increase in growth rate even in fish fed maximally with live brine shrimp. Ferric salt was not judged effective. Addition of ferrous iron also significantly decreased the mortality from hatching to maturity.