a lamprey swims gracefully, revealing its unique mouth structure and vibrant colors in water

animal amphibian wildlife yellow reptile fish frog green nature invertebrate underwater turtle aquarium lizard organism lamprey fish aquatic marine life wildlife underwater nature biology species freshwater predator gills scales ecosystem limbs habitat feeding swimming eyes texture ocean creature anatomy environment vibrant natural river saltwater life cycle biodiversity adaptation water flow survival evolution feeding habits ecological balance behavior world creature feature young bioindicators significance