Phytoplankton Flashcards
What are the main characteristics of phytoplankton?
Unicellular microscopic algae (individuals/chains, float/weakly swim), generally very small in size (most <100um up to 2mm, chains several mm), most have some hard covering (SiO2 or CaCO3, cellulose, highly ornamented)
What is the importance of phytoplankton?
Primary Producers (photoautotrophs - use chlorophyll a and accessory pigments), form extensive blooms (may be toxic), influence atmospheric and aquatic chemistry (nutrient cycling): produce O2, control drawdown of CO2 and sink of carbon to deep waters and sediments, contribute to cloud formation, formed oil, siliceous and limestone deposits, major impact on global climate.
What are the main groups of phytoplankton?
Prokaryotes: cyanobacteria
Eukaryotes: diatoms, coccolithophoes, dinoflagellates
What are the different types of cyanobacteria?
Coccoid cynaobacteria (synechococcus), Prochlorophythes (prochlorococcus), comprise a significant fraction of phytoplankton biomass/productivity. Other is Trichodesmium
What are the characteristics of coccoid cyanobacteria?
Discovered in 1980s b/c orange phycoerythrin fluorescence, solitary cells of in clusters or pairs
What are the characteristics of prochlorococcus?
Discovered later in 1980s from dim red fluorescence of chl a/b, single cell, smallest known photoautotroph
What are the characteristics of trichodesmium
Best known N2 fixer (diazotroph), colonial or free-living filaments
What are the characteristics of diatoms?
Single cells (centric - radial symmetry/pennate - bilateral symmetry), or chains of cells, cell wall (frustule), made of silica or opal, productivity high in areas of upwelling, produce siliceous biogenic sediments (siliceous ooze, diatomaceous earth)
What are the characteristics of coccolithophores?
Unicells or colonies, may have flagella, calcium carbonate coccoliths, Co2 produced during calcifications used in photosynthesis, produce dimethyl sulfide which contributes to cloud formation, produce calcareous biogenic sediments (calcareous ooze, chalk/limestone
What are the characteristics of dinoflagellates?
Unicells and chains, 2 flagella (rotatory swimming motion), atheca made of cellulose plates, can produce bioluminescence and toxins, can produce harmful algal blooms
What are the adaptations in all phytoplankton groups?
Small size to stay afloat, spines to increase drag by increasing surface area:volume, chains to reduce sinking, ionic regulation of cell contents to make them lighter (diatoms), lipid or oil droplets to increase buoyancy, gas vesicles for increased buoyancy, carbohydrate ballast for sinking, flagella for locomotion, rely on turbulent mixing to stay in surface waters
