unio pictorum, painter`s mussel, partially hidden in sand aquatic bivalve mollusk, closeup view

adaptable adult animal aqua aquarium aquatic background biotope bivalve blur clear closeup coldwater decorative detritis endemic eurasian european fauna fish fishkeeping freshwater gravel hidden hobby litter live local macro mollusk mussel native natural nature painters partially photo pictorum river sand shell species specimen substrate tank temperate underwater unio unionidae valve view water widespread wild yellow