Acute Toxicity and Gill Morphology of Oreochromis niloticus (Trewavas) Exposed to Rogor

Abstract

The acute toxicity of Rogor(R) was determined for juvenile bony fish, Oreochromis niloticus in 96-h static bioassays. The fish treated with Rogor(R) showed abnormal behaviour characterised by restlessness, uncoordinated movements, loss of equilibrium, air gulping, loss of buoyancy, periods of quiescence and death. The 96-h LC50 of Rogor(R) for O. niloticus was 0.018 (0.015.022) ml/1. Rogor(R) treatment caused epithelial detachment in the primary and secondary lamellae. It was suggested that osmoregulatory and respiratory incapacitation through mucus accumulation and histologic damage are the major causes of fish mortality following Rogor(R) exposure.

Journal of Aquatic Sciences Volume 14, April 1999, pp. 1-4




KEY WORDS:

Rogor, toxicity, gill, morphology, Oreochromis niloticus