Tuskaloosa darter
The Tuskaloosa darter ( "Etheostoma douglasi" ) is a species of freshwater ray-finned fish , a darter from the subfamily Etheostomatinae , part of the family Percidae , which also contains the perches , ruffes and pikeperches . 
<triplet> subfamily <subj> family <obj> part of <triplet> Etheostomatinae <subj> Percidae <obj> parent taxon