▁along ▁the ▁Atlantic ▁coast ▁from ▁Maine ▁to ▁Florida , ▁and ▁along ▁the ▁G ulf ▁of ▁Mexico . ▁In ▁the ▁Mississippi ▁River ▁they ▁can ▁be ▁found ▁in ▁back w aters ▁and ▁res er voir s ▁as ▁far ▁north ▁as ▁Missouri ▁and ▁Illinois , ▁hundreds ▁of ▁miles ▁in land . ▁ ▁They ▁were ▁introduced ▁into ▁Clear ▁Lake ▁and ▁the ▁Blue ▁L akes ▁of ▁California ▁in ▁ 1 9 6 7 , ▁in ▁order ▁to ▁control ▁the ▁Clear ▁Lake ▁g nat ▁Cha ob orus ▁ast ic opus ▁and ▁mid ges , ▁and ▁in ▁la kes ▁and ▁res er voir s ▁of ▁Al amed a ▁County ▁and ▁Santa ▁Clara ▁County ▁the ▁following ▁year . ▁From ▁there ▁they ▁spread ▁into ▁the ▁San ▁Francisco ▁Bay ▁and ▁Central ▁Valley , ▁and ▁have ▁since ▁become ▁w ides p read ▁in ▁central ▁California . ▁In ▁some ▁areas , ▁they ▁are ▁the ▁most ▁abund ant ▁fish ▁of ▁any ▁species . ▁Mo yle ▁suggests ▁that ▁this ▁fish ▁may ▁have ▁contributed ▁to ▁the ▁dem ise ▁of ▁the ▁Clear ▁Lake ▁spl itt ail , ▁although ▁the ▁effect ▁of ▁the ▁sil vers ides ' ▁introduction ▁on ▁California ▁e cos ystem s ▁not ▁been ▁much ▁studied . ▁ ▁In land ▁sil vers ides ▁are ▁currently ▁an ▁E PA ▁approved ▁indicator ▁species ▁for ▁ac ute ▁marine ▁aqu atic ▁to x icity ▁testing ▁and ▁short - term ▁chron ic ▁to x icity ▁estim ating ▁of ▁marine ▁and ▁est u ar ine ▁organ isms . ▁ ▁Notes ▁ ▁References ▁▁▁ ▁Mo yle , ▁P . ▁B . ▁In land ▁Fish es