Effects of Sublethal Concentrations of the Herbicide, Glyphosate, on Embryonic Development of the Indian Major Carp, Labeo rohita

Abstract

Aquaculture is one of the fastest growing sectors worldwide. Currently, 50% of global fish consumption is provided by aquaculture. In India, the major cultivated fishes are Labeo catla, Labeo rohita, Cirrhinus mrigala, Hypophthalmichthys molitrix, Ctenopharyngodon idella, and Cyprinus carpio. Among these, L. rohita is a widely consumed fish. We aimed to study the effect of one of the most widely used herbicides, glyphosate, on the embryonic development of L. rohita. The 96 h LC50 of glyphosate for L. rohita embryos was found to be 20.89 mgL−1. The embryos were exposed to 1/10th, 1/5th,, and 1/3rd concentrations of LC50 for 96 h. The observed deformities included abdominal curvature, kink formation in the tail, yolk sac edema, pericardial edema, and improperly flattened swim bladder. Besides, we could observe a reduction in pigmentation at 96 h and a decrease in heart rate at 24, 48, 72, and 96 h. All these deformities led to the mortality of embryos. This study indicated that the herbicide (glyphosate) can adversely affect the natural population of the Indian major carp, L. rohita.