Eukarya

• Eukarya includes all organisms with eukaryotic cells

• Examples:– plants– animals– fungi– algae– single-celled animal-like protozoa

Protists• Eukaryotic; but comprises its own Kingdom Protista

– Algae - aquatic, photosynthetic organisms– Diatoms– Dinoflagellates– Protozoans – Foraminiferans, Radiolarians, Ciliates

• Single and multi-cellular

Unicellular Algae• Green Algae

– Mostly freshwater and terrestrial– 10% of species are marine

• Brown Algae– Almost all species are marine– Sargassum (Sargasso seaweed)– Macrocystis (Giant Kelp)

• plants grow up to 300 ft• can grow 20”/day • form kelp beds or kelp forests• Harvested for Algin (used in cosmetics and ice cream).

• Red Algae– Agar and carrageenan: gelling and thickening agents

Diatoms• Extremely diverse and distinct

members of marine phytoplankton– Unicellular

• Diatom structure– Enclosed in a box-shaped

organic cell wall with silica (SiO2), called a frustule

– Holes in cell wall allow cholorplast to capture light and dissolved gases to enter.

Dinoflagellates– Unicellular protists with 2 flagella (used for motility) – Globular, plated outer “shell” that is made of cellulose– Photosynthetic, but also can absorb nutrients – Most are planktonic (primary producers)– Can be bioluminescent – Bioluminescent Bay, Puerto Rico (pg. 97)

• Red tides – produce toxin in water when in Harmful Algal Blooms (HABs)

Amoeboid Protozoans• Unicellular Protists• All have an organelle called a pseudopod—an extension of the

cell surface that can change shape and is used for locomotion and food capture

• Are heterotrophs consuming bacteria and other small organisms

Amoeboid Protozoans

Amoeboid Protozoans

• Major Protozoans: – Foraminiferans–Radiolarians–Ciliates

Amoeboid Protozoans• Foraminiferans (forams)– have branched pseudopods that form elaborate,

net-like structures used to: • snare prey• crawl• reduce sinking rate (pelagic)

– consume bacteria and diatoms– some harbor symbiotic green and red algae and

zooxanthellae– Have shell (test) made from CaCO3

– Bottom of the ocean (benthic)

Foraminiferans

Foraminiferans• White Cliffs of Dover

Radiolarians• Unicellular protists • Planktonic (primary producers)• Shells make of silica (glass)• Contains a needle-like pseudopodia• Dead remains cover large portions of the

ocean bottom as radiolarian ooze.

Radiolarians

Ciliates• Ciliates– protozoans that have cilia (hair-like growths) for

locomotion and for gathering food• membranelles—tufts or long rows of fused adjacent cilia• Heterotrophs – cytostome—an organelle serving as a

permanent site for phagocytosis of food– planktonic major links in marine food chains– form symbiotic and parasitic relationships– Paramecium

Ciliates

Fungi• General features of fungi– eukaryotes with cell walls of chitin– filamentous fungi grow into long, multi-cellular

filaments called hyphae that can branch to produce a tangled mass called a mycelium

– Important to marine ecosystems as heterotrophic decomposers that recycle organic material

Maritime Lichens

• Lichens: mutualistic associations between a fungus and an alga– fungi are usually ascomycotes– algae are usually green or blue-green bacteria

• The fungus provides attachment, general structure, minerals, moisture

• The alga produces organic matter through photosynthesis

Marine Viruses• Viruses are diverse and are more abundant than

any other organism in the sea• Have significance for marine food webs,

population biology and diseases of marine organisms

• Viruses of marine eukaryotic hosts first reported in the 1970s

Biodiversity and Distribution of Marine Viruses

• 10 times more abundant than marine prokaryotes, may reach 1010 virons per liter of seawater, 1013 per kilogram of sediment

• Estimated 100 to 10,000 genotypes• Most planktonic viruses are icosahdral or binal

bacteriophages (“bacteria eaters”) with lytic life cycles

• Sediment viruses are typically helical and lysogenic

Marine Microbes

• http://www.youtube.com/watch?v=1TmHlcMDIOQ