stick·le·back 
(stĭkəl-băk′)
(stĭkəl-băk′)n.
Any of various small freshwater and marine fishes of the family Gasterosteidae, having erectile spines along the back.
[Middle English stikelbak : Old English sticel, prick; see steig- in the Appendix of Indo-European roots + Middle English bak, back; see BACK1.]