THE EFFECT OF LEAD ION ON THE GROWTH AND SURVIVAL RATE OF Oryzias curvinotus FROM STAGE 1 TO 10 DAYS OLD

Abstract

Lead ion is one of the cations that affects the vitality, growth ability, causing skeletal deformities in fish development. This study was conducted to evaluate the effect of lead ion (Pb²⁺) on 1 to 10-day-old Oryzias curvinotus larvae at different concentrations: 0 µg/L; 50 µg/L; 100 µg/L; 150 µg/L. The results revealed that: (i) the minimum Pb²⁺ concentration affecting the medak survival rate is 50 µg/L; (ii) the Pb²⁺ concentration significantly affecting the survival rate on the 5^th day is 150 µg/L. Based on the obtained results, we offered an equation to predict the survival rate of fish larvae and discovered the lethal LD₅₀ concentration of Pb²⁺ after 10 days culturing is 98 µg/L and LT₅₀ of Pb²⁺ at the concentration of 150 µg/L is 9,76 days. In conclusion, the higher concentration of Pb²⁺ causes the lower survival rate and the higher skeletal deformities of Oryzias curvinotus; the most effective concentration is 150 µg/L.