▁e colog ical ▁im bal ance ▁as ▁a ▁strange ▁species ▁of ▁fish ▁has ▁domin ated ▁its ▁e cos ystem . ▁Since ▁the ▁late ▁ 1 9 9 0 s , ▁the ▁Mar ik ina ▁River ▁has ▁been ▁inf ested ▁by ▁jan itor ▁fish . ▁Before , ▁the ▁river ▁was ▁th riv ing ▁with ▁local ▁species ▁mart in iko , ▁ay ung in ▁and ▁bi ya . ▁ ▁The ▁growing ▁fish ▁population ▁has ▁prompt ed ▁the ▁city ▁government ▁to ▁launch ▁a ▁new ▁program ▁to ▁control ▁their ▁number . ▁The ▁city ▁issued ▁Ord in ance ▁ 0 0 4 , ▁series ▁of ▁ 2 0 0 7 , ▁launch ing ▁Jan itor ▁Fish ▁Er adic ation ▁Drive ▁in ▁the ▁City ▁of ▁Mar ik ina , ▁grant ing ▁c ash ▁in cent ives ▁to ▁participants , ▁appropri ating ▁ann ually ▁fifty ▁thousand ▁P es os ▁( ▁for ▁the ▁purpose . ▁ ▁A ▁scientific ▁study ▁of ▁the ▁species ▁found ▁in ▁five ▁locations ▁in ▁the ▁Lag una ▁de ▁Bay ▁trib ut ary ▁system , ▁including ▁the ▁Mar ik ina ▁River , ▁revealed ▁that ▁the ▁spec imen ▁of ▁jan itor ▁fish ▁previously ▁reported ▁as ▁Hyp ost om us ▁ple cost om us ▁actually ▁belong ▁to ▁the ▁genus ▁P ter yg op lich th ys , ▁family ▁Lor ic ari idae . ▁The ▁collected ▁spec im ens ▁for ▁this ▁study ▁consisted ▁of ▁two ▁species ; ▁P ter yg op lich th ys ▁dis j unct iv us ▁and ▁P ter yg op lich th ys ▁p ard alis . ▁Both