Organizing the diversity Systematics; studying the diversity Taxonomy to classify organisms & groups

Domains Bacteria & Archaea Domain Eukarya Prokaryotic Bacteria and bacteria-like Simpler Smaller cell size DNA without nucleus Cell wall & other crude protective layers Lack organelles Eukaryotic Protista, Plants, Fungi, & Animals Complex >cell size; 10x larger DNA in nucleus Cell membrane Some also have cell wall Membrane bound organelles specialization

Bacteria Morphology Feeding Oxygen pathways Decomposers Rods (bacilli) Spheres (cocci) Spirals Feeding Heterotrophic Autotrophic Photoautotrophic Chemoautotrophic Oxygen pathways Aerobic Anaerobic Facultative anaerobic Decomposers Breakdown DOM Ammonia → nitrate N2 gas → NH4 → nitrate

Archaea Similar in shape and simplicity to Bacteria Extremophiles Share some genetic similarities with Eukaryotes Extremophiles Temperature (>/= 121o) Salinity pH e.g. hydrothermal vents

Other fun marine microbes Unicellular algae Plant-like Protists Mostly photosynthetic Autotrophs converting light E to ATP Primary producers Planktonic Drift in the water column

Diatoms: Phylum Bacillariophyta Silicon shell = frustule Glass-like 2 halves like a petri dish Major planktonic 1o producer Dead sink forming much of biogenous sediments

Diatom reproduction

Dinoflagellates “spinning flagellates” Grooved perpendicular flagella Some produce toxins (like some diatoms) Poison accumulates in shellfish; poisons consumers Red tides Bioluminescent Zooxanthellae Photosynthetic symbionts of anemones and corals

All are important planktonic 1o producers Chrysophyta Silicoflagellates Star shaped; silicon Desmids Pectin & silican walls Golden or yellow Coccolithorids Calcium carbonate coccoliths All are important planktonic 1o producers Emiliania huxleyi (E. huxleyi)

Protozoans Animal-like protists Heterotrophs Unicellular or colonial Various forms Foraminiferans Have a CaCO3 shell Thin extended pseudopods Planktonic or benthic Adds to the calcareous sediments Radiolarians Silica shells; thin pseudopods; planktonic; silicious sediments Ciliates Aggregate shells or sand particles Crown of cilia

Fungi Heterotrophic Decomposers Some parasitic Some symbiotic Breakdown DOM Some parasitic Some symbiotic w/ algae &/or cyanobacteria = Lichens Fungi provide structure & support (home); algae provides photosynthesis products (sugars)