plankton. phytoplankton can’t move against currents (float or weakly move) >40% of global...
TRANSCRIPT
Plankton
Phytoplankton
• Can’t move against currents (float or
weakly move)
• >40% of global primary productivity
Phytoplankton Classification
From two kingdoms Monera (bacteria)
Protista (algae)
3 divisions (Phyla)CyanobacteriaChrysophytaDinophyta
Cyanobacteria
•Photosynthetic bacteria •Prokaryotic (No
nucleus, few organelles)
•Reproduce by cell fission
•Nitrogen fixation: convert Nitrogen gas
(N2) to nitrates or ammonia
Chrysophyta• Most with hardened cell walls or
internal skeletons: silica or calcium carbonate (CaCO3)
•Some have flagella for motility
Coccolithophores – type of Chrysophyta
Calcium CaCO3 plates
•large numbers at surface
•Prefer still, nutrient-poor H2O
•Reflect sunlight: lower heat & UV light – counter global warming
Diatom – type of Chrysophyta
• Most abundant phytoplankton
• Major oceanic primary producer
• Cell walls (frustule) of silica (glass-like)
• Live alone or in chains
Dinophyta
Dinoflagellates
•Most photosynthetic, few heterotrophic
•Unicellular, 2 flagella: adjust vertically in
water column (light, nutrients)
•Rapid asexual cell division
Dinoflagellates
• Abundant in warm surface H2O (tropics)
•Some symbiotic (zooxanthellae)–Live in coral, clams, urchins, anemones
•Zooxan. give carbohydrates & receive nutrients & shelter
Dinoflagellates areBioluminescent
• Organisms produce light by a chemical reaction
Why Do Dinos. Produce Light?
Camouflage!
•When it senses a predator
(motion in H2O)
•Which attracts larger predators that
consumes the would-be Dino predator
Red Tides (Dinoflagellate Bloom)
• Mass development of dinoflagellates discolor water
•Often caused by excess nutrients
•Enter ocean from land (runoff)
•Fertilizer, sewage
Red Tide Impacts:
• Toxic to marine life: accumulates in clams, mussels, scallops, fish, mammals
•Death to some species, Human poisoning after consumption (30 min.)
•Symptoms:
•Paralytic: paralysis, asthma, heart attack (rare)
•Neurotoxic: tingling, paralysis,
memory loss
•Diarrhetic: cramps, vomiting, diarrhea
Special PlanktonicAdaptations
Unique shapes –increase surface areas•Gas filled-vesicles•Oils•Hard shells