AP BIOLOGY

Detailed explanation-1: -Important metazoan zooplankton include cnidarians such as jellyfish and the Portuguese Man o’ War; crustaceans such as cladocerans, copepods, ostracods, isopods, amphipods, mysids and krill; chaetognaths (arrow worms); molluscs such as pteropods; and chordates such as salps and juvenile fish.

Detailed explanation-2: -Zooplankton are small (normally less than 2 mm long) aquatic invertebrates, including copepods, cladocerans (water fleas), and rotifers, living in the water columns of lakes or slow-moving streams.

Detailed explanation-3: -Zooplankton include microscopic animals (krill, sea snails, pelagic worms, etc.), the young of larger invertebrates and fish, and weak swimmers like jellyfish. Most zooplankton eat phytoplankton, and most are, in turn, eaten by larger animals (or by each other).

Detailed explanation-4: -In addition to phytoplankton and zooplankton, two even smaller kinds of plankton can be found floating in the sea. Bacterioplankton are bacteria and virioplankton are viruses.