Effect of Paraquat on Tilapia Fingerlings under laboratory condition

D.K Nkeeh,N.A Jamabo

doi:10.4314/jasem.v23i7.5

Abstract

A total of 150 fingerlings of Tilapia guinensis, were acclimated for a period of 14days. A static bioassay was used during the period of the experiment. Mortality was measured at different time intervals of 10hr, 12hr, 16hr, 20hr, 46hr and 52hr for the range finding test, using different concentrations of paraquat (120mg/l, 60mgl, 30mg/l and 15mg/l). Acute toxicity test, using different concentrations of paraquat (10mg/l, 5mgl, 2.5mg/l and 1mg/l) was used to measure mortality of 4, 0, 0 and 0 respectively, for 96hrs. The test established the LC50 (10mg/L) of paraquat on fingerlings of T.guinensis. Three sublethal treatments (5mg/L, 2.5mg/L and 1mg/L) and five lethal treatments (120mg/L, 60mg/L, 30mg/L, 15mg/L and 10mg/L) were used during the period of the experiment. The higher the concentration (30mg/L,60mg/L and 120mg/L) of paraquat, the higher the mortality (0, 1 and 5) by the end of 10hr, thus the dose of the test chemical made the poison. Although herbicide such as paraquat can be used in the control of weed; biological and mechanical weed control methods are still better as they may pose little or no threat to the life of T. guinensis.Keywords: Acclimated, Tilapia guinensis, acute bioassay, paraquat and LC50

Highlights

The rapid increase in human population has escalated the demand for quality food, like fish, in the world
Adverse effect can be seen on other organisms, other than the one intended as a result of indiscriminate use of herbicide in the environment, aquatic organisms (Nwani et al, 2011)
This study is aimed at assessing the effect of paraquat on fingerlings of T. guinensis with the following objectives; to determine the LC50 of paraquat in T. guinensis and to assess the effect of paraquat on general growth and development parameters of tilapia fingerlings

Summary

Introduction

The rapid increase in human population has escalated the demand for quality food, like fish, in the world. Aquatic living organisms can be adversely impacted, if the chemicals are used indiscriminately It is a common practice in agriculture globally, to use herbicide in the control of weeds, mainly with the view of improving the production of agricultural products. Paraquat is used to control weeds before and after planting in more than 100 crops, including major food crops: corn, rice, soya, wheat, potatoes; major fruits: apples, oranges, bananas; beverages: coffee, tea, cocoa; and processed crops: cotton, oil palm, sugarcane, and rubber (PIC, 2017). In fruits such as sugar canes and pineapples paraquat serve a desiccative purpose (Tomlin, 1994). This study is aimed at assessing the effect of paraquat on fingerlings of T. guinensis with the following objectives; to determine the LC50 of paraquat in T. guinensis and to assess the effect of paraquat on general growth and development parameters of tilapia fingerlings

Objectives

Methods

Results