zander or pike-perch sander lucioperca, closeup photo of a juvenile freshwater fish in aquarium

animal aqua aquarium aquatic biotope bug caudal clear closeup decorative dorsal driftwood elodea endemic europe european eye fauna fin fish fishkeeping freshwater gravel juvenile lips live local lucioperca macro mouth native natural nature operculum photo pikeperch plant predator rare river sander southern squama tank twig underwater water weed wild young zander