healthy active adult specimen of european bitterling, rhodeus amarus, little omnivore ornamental fish in a temperate biotope

acheilognathinae active adult amarus animal aqua aquarium aquatic behaviour biotope bitterling clear coldwater cyprinid driftwood ecology endemic europe european fauna fin fish fishkeeping free freshwater funny gravel grey gudgeon healthy hornwort ichthyology line litter little local look macro mouth natural nature omnivore ornamental pair plants potamogeton protection rhodeus river space specimen swim tank temperate topmouth underwater water watermilfoil weed widespread wild