The Effect Of Methomyl On Growth,Antioxidant System Of Gift(Oreochromis Niloticus) In The Presence Of Water Spinach(Ipomoea Aquatica Forsk) As Floating Bed And Methomyl Residue In The Plant

The world is faced with the challenge of preserving a safe and ideal place for life during this period that mankind is depending on pesticide to improve agriculture.Methomyl is one of the pesticides that is widely used for this purpose.Water spinach is an economic and a medicinal plant and will help in the degradation of methomyl.This study was conducted to investigate the effect of methomyl on growth and antioxidant system of GIFT in presence of water spinach(Ipomoea aquatica)as floating bed,methomyl residue in the plants and nutrient removal from tilapia cultivation wastewater using water spinach as floating bed.In this study,we aimed to investigate the effects of methomyl at different time intervals on the antioxidant enzymes:superoxide dismutase(SOD),catalase(CAT)and glutathione(GSH).Four treatment groups are established;control,2.0 μg/L,20.0 μg/L and 200 μg/L.Each treatment having three replicates.And concentrations are based on the U.S.EPA drinking water quality which established a maximum permissible concentration for methomyl of 200μg/L.The water spinach were planted in floating bed.Fifteen GIFT groups are introduced into each sub-lethal dose in an open-static system with the total experimental fish of One hundred eighty(180).Eight hundred grams(800 g)of water spinach(Ipomoea aquatica)is added to all the experimental tanks,including the Control with the weight of water spinach coming up to nine thousand six humdred grams(9600 g).Juvenile tilapia are exposed to methomyl contaminated water for 60 days.The fish were served twice a day;8:00 am and 5:00 pm respectively.Before taking samples,the fish were left to fast for a day and three fish were caught and slaughtered for sample extraction.Samples of the plant’s leaf,stem and root were extracted three times for methomyl residue at an equal interval,dried in an electrical oven at the temperature of 105℃.It was powdered and The plant samples was put into a 50 ml centrifuge tube and mixed with 10 ml Acetonitrile and homogenized at 2500 rpm for 5 minutes,centrifuge at 3500 for 5 min(this was done twice),and the supernatant transferred into a 50ml tube and taken to the Solid Face extraction for further extraction.Here,10 ml acetonitrile-toluene(3:1 v/v)was use to activate the cartridge and the supernatant was filtered through the cartridge.20ml acetonitrile-toluene(3:1 v/v)was measured and 2 ml used 3 times to wash the tube and add to the cartridge.The cartridge was then eluted with the 18 ml acetonitrile-toluene(3:1 v/v).The eluent was then collected and evaporated to dry at 40℃ using the rotary evaporator.The dried residue was dissolved in 1 ml acetonitrile and filtered with 0.45 μm organic membrane filter using a syringe.And the sample was taken to HPLC for analysis.Results shown that at moderate temperature such as 25℃ to 30℃,tilapia increase their feed consumption and improve body weight.At very low temperature and high temperature,the pace of feeding in GIFT reduces.,the levels of contents of SOD,CAT and GSH indicated significant increase in the liver of GIFT in triplicate.The results showed that methomyl could reduce the growth rate of GIFT,and water spinach could reduce part of the water quality indexes in<200 μg/L methomyl group.Water spinach alters GIFT’s liver oxidation system to some extent and effectively absorb methomyl in water and transfer to itself and the degradation was lower than the dietary standard through 15-20 days.Growing water spinach in farmed waters partially decomposes methomyl and prevents it from causing damage to GIFT’s liver.