eurasian ruffe, gymnocephalus cernua, ruffe or pope, small freshwater predator fish, side view in european river biotope aqua

adaptable adult amano animal aqua aquarium aquatic background beast biological biotope cernua clear closeup dark decorative eco ecology endemic eurasian european eye fauna filtering fin fish fishkeeping freshwater gray gymnocephalus hobby line lips litter live macro mouth native natural nature percidae photo pope predator river root ruffe sand side small substrate tank underwater view vulnerable water widespread wild willow