copepod zooplankton are a group of small crustaceans

animal aquatic background biological biology copepod crustacean eggs fauna fish isolated laboratory lake life macro macrophotograph macrophotography marine metazoa micro microphoto natural nature nauplius nucleus ocean oceanography pacific peaceful phytoplankton plankton planktonic poison research science sea see swim tentacles translucent transparent tropic veterinary water wild wildlife zoo zoological zoology zooplankton