Effects of chlorphoxim on the brain acetylcholinesterase activity of tilapia zilli

,r,-T' l\rqf /t:v'rzra lc:r , .,"-,, "J\tl .. : J t,1l o /.r+ Effetcs of ctrlorphoxjn on the brain Acetylcholinesterase activiff of Tilapia Zil1i By L.A.I(. Antwi Original : English Sunq,ar.'v A study r.ras conilucted. in the xiver i'iarahoue wittr ca6ed. Tilapia Zi1.Ii during one of the weekly tr.eatrnents of the river with chlorphoxirn. The objective of the stu(y r,las to fintl out how far downstream from ttre point of its release, the larvicide induces a red.uction in the brain acetylcholinesterase (lCnU) activity of fish ch:ring a river treatupnt. the caged. fish r.rere placed in ttre treated. rirrer at the following distances from the treatnent site: 0lsn,0.5 i{lr, 1.0h and J.0 }<rn. ltre results showed. ttrat 24 hours after the river treatnent witlr chlorptroxim at a concentration of 0.0! pprn, the highest leve1 of 1t.65 o/o enzyme ir:hibition vras xecord"ed. in ttre caged. fistr placed. near the point of r.elease of tl:e larvicid.e (O t*). At 0.5 1o d.ownstream of the treatnent site, the percentage enzyme red.uction rt,as 21.7) and at 1*re 1.O h point, 1,he fish bra jn enzynre activi W was red.uced. by 16.12%. TLrere was no significant red.uction in the brain ACtrE activiW of caged fish placed. at a distarce of about ,.0 lsn d.ownstream below the treatment site. It r.ras furttrer observed. that after {B hours in the treated. rivet', the caged. fish had. not recovered from tJ:e inhibitory effect of the larvicide. A similar ca5pd fish experiment conducted. in the Black Volta treated. with lemephos (eUate) showed. Urat this larvicid.e did. not induce argr significant red.uction in the caged fish enzyrne activiff at arry d.istance from its point of release in the treated. river. this confi:ms ti:at chlorphoxjm is more toxic to fish than temephos. oc"/YsJ /LIYBTO /55.4 \Effetcs of chlorphoxi.m on ttre brain Acetylcholinesterase '" activif of TiLapia Zil1i BV L.A.K. Antwi 0riginal : English Sunmar:y A study r,ras conducted in the river l,larahoue r*ith ca6ed. Tilgcia 2i1.1_i d.uring one of the veekJy treatroents of the river with chlorptroxim. l:e objectiye of the study r,ras to find. out hor.r far downstream from the point of its release, the larvicid.e ind.uces a red.uction in tfte brain acetlrlcholinesterase (aO:n) activity of fish cluring a river treatrient. the caged. fish r,rere placed. in the treated. rirrer at the follor,ring d.istancesll J from ti:e treatznent site: 01sn, 0.5 lm, 1.01sn and- ).0 1glr. &re results showed lhat 24 hours after the rj-ver treatnent with chlorpLroxim at a concentration of 0.05 ppm, the highest 1evel of 1t.66 o/o enzyme ir:kribition wELs record.ed- in ttre cagsd. fislr placed. r:rear t.Le point of r"elease of the larvicid.e 1O to,). At 0.5 Im downstream of the treatnent site, tJre percentage enzyme reduction tras 21.71 and at tkre 1.0 lrn point, the fish braj:: erlz]rme activity was reduced. by 15.12 ?/o. There was no significant red.uction jn the brain ACtrE activity of ca5ed. fish placed at a distarce of about 1.O km dor.rnstrgam below tJre treatment site. It r+as further observed. ttrat after {B hours in the treated. rivef, the caged. fish had. not r.ecovered. from the inhibitory effect of the larvicide. A similar caged. fish experiment conducted in the Black Vo1ta treated. wittr lemephos (eUate) showed ttrat ttris larvicide d.id not induce argr significant red.uction in the caged fish enzyme activity at any distance from its point of release in ttre treated. river. fr:is confi:rns that chlorphoxim is more toxic to fish than temephos.