Zooplankton

Zooplankton Animals and animal-like organisms that float and drift Unicellular protists and multicellular (jellyfish) Most are microscopic Crab Larvae

Diversity Meroplankton Temporary Embryos or larvae of fish, crabs, sponges, lobsters, clams, and other invertebrates Mature and settle to bottom as adults Slipper Lobster Larva

Diversity Permanent Zooplankton Species that remain in the plankton population for whole life cycle Foraminiferan (Foram) Hole-bearing Unicellular protist Encased in calcium carbonate shell Parts of cytoplasm flow out through holes to catch food Dead organisms form chalk deposits (Cliffs of Dover)

Diversity Radiolarian Permanent Unicellular Cell wall of silica Transparant Long spines like spokes of a wheel for buoyancy and protection

Diversity Copepod Most numerous Tiny, shrimp-like animal (size of a grain of sand) Feeds on phytoplankton (diatoms) Eaten by larger zooplankton, fish, and whales Important link in many food chains Copepod!

Sea Soup Plankton are tiny food particles suspended in the “soup” Whales feed by straining food from water, called filter feeding Krill (4-5 cm) Shrimp like zooplankton In Antarctic Potential food source for humans

Sea Soup Plankton form the foundation of the marine food chain Bottom dwelling mollusks (muscles, clams, oysters, scallops) filter feed on plankton Clams Cells inside have microscopic cilia that create a current through body

Protozoans Includes forams and radiolarians Found on surface and in bottom sediments Unicellular Animal like Kingdom Protista Subdivided into 3 phyla: Ciliophora Zoomastigina Sarcodina

Sarcodina Forams, radiolarians, and amoebas Live on surface of substrates Move and eat using psuedopods

Sensitivity Ability of an organism to respond to environmental stimuli Vorticella Responds to touch by contracting its stalk into a coil Avoidance reaction to stimuli that may be harmful Also contracts spontaneously

Reproduction Vorticella Paramecium Asexual reproduction Binary fission – division of prokaryotic cell into 2 identical cells Paramecium Sexual reproduction Conjugation 2 parent protozoans exchange parts of their micronuclei when they come in contact (exchange genetic material) Increases genetic variation Binary fission then occurs, but with unique offspring.