PLANKTON Ocean Wanderers

Going with the Flow Weak or non- swimmers May move up and down in the water column

Holoplankton Spend their whole life as plankton

Meroplankton Limited planktonic existence (larvae)

Can ya see ‘em? Micro (large protists, small metazoans) –20 – 200 um –Not visible to naked eye

Nanoplankton Small protists (2-20 um)

Picoplankton Marine bacteria (0.2 – 2 um) Some bioluminescent

Femtoplankton Marine viruses (really teeny tiny – less than 0.2 um)

Yep! You can see ‘em! The big guys –Megaplankton –Macroscopic –Visible –20+ cm. –Jellyfish

Macroplankton Pteropods (2 – 20 cm; sea butterflies; snails with small shells)

Mesoplankton Copepods (0.2 – 2 cm)

Where Everywhere –Foundation of ocean food web

Phytoplankton Diatoms silica shells (tests) single cells or chains yellow-green or brown

Diatomaceous Earth Formed from fossilized diatom skeletons Soft, chalky sedimentary rock Used for –Filtration –Cat litter –Mild abrasive, etc.

Phytoplankton, cont. Dinoflagellates –Single-celled –Brown –Cause “red tides” –Produce saxitoxin (paralytic) –May be bioluminescent –Some have cellulose shell

Still more Phytoplankton Cyanobacteria –Small (~2 um) –Unicellular, but may grow in large colonies (visible) –Important producer

And more (phytoplankton) Coccolithophores –Ca shell (coccoliths) –Blooms may give water a milky appearance –When eaten, plates excreted and fall to ocean floor –Warmer water

Zooplankton Radiolarians –Single-celled –Silica tests –May have zooxanthellae –Name comes from shape

More Zooplankton Foraminiferans –Single-celled –Ca shell –Have pseudopods –Warmer water

The White Cliffs of Dover Formed from the shells of: –coccoliths –forams –Other Ca shells Include layers of silica from: –Diatoms –Radiolarians, etc.

Still more Zooplankton Zooflagellates Ciliates –Engulf food –Propelled by cilia or flagella

Macrozooplankton I Jellyfish –12 mm to 2m (2.5m?) across –Up to 40m (60m?)long –Up o 300 – 500 lbs. –Toxin may affect Nervous system Muscles Blood cells Cause tissue necrosis

Macrozooplankton II Siphonophores –Colonies of animals –Cnidarians –Includes Portugese Man-of-War –may be Earth’s most abundant predator –bioluminescent

Macrozooplankton III Copepods –Small crustaceans –Omnivores –Rudimentary eyes

Macrozooplankton IV Krill –Shrimplike crustaceans –Up to 5cm and 1g –Dense schools in cold water –Most are filter-feeders –An important food for other animals

Still more Macrozooplankton Larvae of larger marine critters (fish, mollusks, crustaceans, echinoderms, etc.)

Macrozooplankton…. Salps –Tunicates (primitive chordates) –Individual or in colonies –Microscopic up to 12cm

? What will happen if climate change causes the oceans to become more acidic? (Presently, ocean water is slightly alkaline.)