▁of ▁much ▁larger ▁tr out , ▁up ▁to ▁ ▁in ▁weight , ▁with ▁bright ▁yellow ▁fins . ▁ ▁Disc overy ▁and ▁naming ▁In ▁July ▁ 1 8 8 9 , ▁Professor ▁David ▁St arr ▁Jordan ▁and ▁G . ▁R . ▁Fish er ▁visited ▁T win ▁L akes ▁and ▁published ▁their ▁discover ies ▁in ▁the ▁ 1 8 9 1 ▁Bul letin ▁of ▁the ▁United ▁States ▁Fish ▁Commission . ▁They ▁found ▁both ▁the ▁green back ▁and ▁what ▁they ▁proc laimed ▁to ▁be ▁a ▁new ▁species ▁the ▁" yellow fin ▁cut th ro at ". ▁In ▁the ▁species ▁description , ▁published ▁in ▁the ▁ 1 8 9 0 ▁edition ▁of ▁the ▁Pro ceed ings ▁of ▁the ▁United ▁States ▁National ▁Museum , ▁Jordan ▁and ▁Ever mann ▁described ▁the ▁fish ▁as ▁follows : ▁Color , ▁sil very ▁o live ; ▁a ▁broad ▁le mon ▁yellow ▁sh ade ▁along ▁the ▁sides , ▁lower ▁fins ▁bright ▁golden ▁yellow ▁in ▁life , ▁no ▁red ▁anywhere ▁except ▁the ▁deep ▁red ▁dash ▁on ▁each ▁side ▁of ▁the ▁thro at . ▁The ▁sub species ▁was ▁scientific ally ▁named ▁mac don ald i ▁after ▁the ▁US ▁Fish ▁Commission er , ▁Marshall ▁Mc Donald . ▁ ▁Jordan ' s ▁spec im ens ▁were ▁re - ex am ined ▁by ▁the ▁fish eries ▁bi ologist ▁Robert ▁J . ▁Be hn ke , ▁who ▁commented , ▁" I ▁have ▁no ▁doubt ▁that ▁Jordan ▁was ▁correct ; ▁the ▁yellow fin ▁tr out ▁and ▁the ▁green back ▁tr out ▁from ▁T win ▁L akes ▁were ▁two ▁distinct ▁groups ▁of