Size, Speed and Buoyancy Adaptations in Aquatic Animals

摘要: Animals are denser than either fresh water or sea water, and therefore tend to sink, unless they have adaptations that give buoyancy. Very small organisms sink slowly, reproduce rapidly can be kept suspended by natural turbulence: individuals lost sinking replaced reproduction. This is likely effective only for of less 150μm diameter. Larger animals will swim evolve buoyancy organs. Hovering one the options available them, but “hop sink” technique used some copepods more economical steady hovering. Another option use fins as hydrofoils, sharks, tunnies many squids do. implies an energy cost because work has done against drag on hydrofoils. Many made buoyant gas-filled floats, low-density organic compounds body fluids unusual ionic composition. Such aids increase swimming at given speed animal's bulk. Buoyancy hydrofoils slowly those fast.