Energy in Aquatic Systems  Photosynthesis = Traps light energy in glucose. (= Most important.) 6CO 2 + 6H 2 O + light → C 6 H 12 O 6 + 6O 2  Chemosynthesis = Transfers chemical energy from H 2, H 2 S, or CH 4 to energy in glucose (or another organic form) 6CO 2 + 6H 2 O + 3H 2 S → C 6 H 12 O 6 + 3H 2 SO 4  Glycolysis + Cell. Respiration = Release energy in glucose in cell. useful from (ATP). 6O 2 + C 6 H 12 O 6 → 6CO 2 + 6H 2 O + ATP

Energy in Aquatic Systems  Photosynthesis requires light and CO 2. 6CO 2 + 6H 2 O + light → C 6 H 12 O 6 + 6O 2  Photosynthetic organisms also require nitrate (NO 3 - ) and phosphate (PO 4 - ) for protein synthesis = macronutrients  Aquatic photosynthesis most commonly is light and/or macronutrient limited. - Deeper = less light - More turbid = less light - Dead things and poop sink taking their macronutrients away from light

 Benthic = associated with the bottom.  Pelagic = in the water column.  Neuston = associated with the surface.  Fringing = associated with the terrestrial margin.  Macrophytes = multicellular and macroscopic photosynthetic organisms.  Microphytes = unicellular and filamentous photosynthetic organisms. Phytobacteria = photosynthetic bacteria. Organisms: Habitat Classification Photosynth. Org. Classification

Benthic Organisms  Epifauna = animals and protozoans attached to or on the bottom.  Infauna = animals and protozoans that live in the substrate. Photosynthetic  Periphyton = microphytes attached to the substrate.  Attached Macrophytes  Epiphyton/Epiphytes = microphytes attached to macrophytes.

Pelagic Organisms  Nekton = animals that can swim against horizontal currents.  Plankton = organisms that cannot swim against horizontal currents; “drift” in water column. (Size is irrelevant. E.g., Most jellyfish are planktonic.) Holoplankton = organisms that spend their entire lives “drifting” in the water column. Meroplankton = organisms that spend their early lives “drifting” in the water column.

Pelagic Organisms  Phytoplankton = microphytes that “drift” in the water column.  Floating Macrophytes  Epiphyton/Epiphytes = microphytes attached to macrophytes.  Zooplankton = animals and non- photosynthetic protozoans that “drift” in the water column (and feed on other plankton). Microzooplankton = non-photosynthetic protozoans (& VERY small animals) that “drift” in the water column.

Organisms in the Neuston  Most require very still surface water. Most are insects and mites and a very few floating larger organisms. Organisms in Fringing Communities  A mixture of aquatic and terrestrial kinds of organisms.  Emergent macrophytes = multicellular and macroscopic photosynthetic organisms that emerge from the water.

Pelagic Food Web grazing zooplankton predatory zooplankton nekton microzooplankton bacteria phytoplankton phytobacteria dissolved organic compounds (DOC)

Taxonomic: Microphytes  Cyanobacteria = photosynthetic bacteria; phytoplankton, periphyton/epiphyton  Diatoms = unicellular photosynth. eukaryotes w/glass (silica) cell walls; phytoplankton, periphyton/epiphyton  Dinoflagellates = unicellular photosynth. euks. with 2 flagella; phytoplankton, periphyton/epiphyton  Coccolithophores = unicellular photosynth. eukaryotes w/ CaCO 3 “parasols”; phytoplankton

Taxonomic: “Major” Algal Groups  Green Algae = unicell. OR multicell. photosynth. euk. w/cellulose cell walls; phytoplankton, periphyton/epiphyton, a few macrophytes  Red Algae = mostly multicell. photosyn. euks. w/cellulose cell walls & red pigments; most macrophytes, a few periphyton/epiphyton  Brown Algae = mostly multicell. photosynth. euks. w/various cell walls & brown pigments; most macrophytes, a few periphyton/epiphyton

Flowering Plants  Multicellular photosynthetic euks. w/cellulose cell walls; common in freshwater; all macrophytes VERY FEW marine flowering plants.  Mangroves – MARINE/estuarine emergent woody  Spartina (saltmarsh grass) – saltmarsh emergent and fringing  Eel/sea grass – MARINE submerged

Solely Aquatic Phyla  Sponges – soft, calcareous, and glass sponges; most marine; all epifaunal  Cnidarians – jellyfish, sea anemones, corals; most marine; many planktonic, a few nektonic, many epifaunal, a few infaunal  Echinoderms – starfishes, sea urchins, sea cucumbers, & sea lillies; ALL marine; most epifaunal, a few infaunal

“Worms”  Annelids (segmented worms) – leeches, earthworms, polychaete, & tube worms; freshwater and marine; epifaunal, infaunal  Nematodes (roundworms) – most microscopic; freshwater and marine; a few planktonic, most epifaunal or infaunal, many parasitic  Platyhelminths (flatworms) – planarians, tapeworms, & flukes; freshwater and marine; many epifaunal, many parasitic

Mollusks  Bivalves – clams, oysters, mussels, & scallops; freshwater & marine; meroplanktonic marine larvae, epifaunal, infaunal, fringing  Gastropods – snails and slugs; freshwater and marine; meroplanktonic marine larvae, epifaunal, infaunal, fringing  Cephalopods – squid, octopus, & cuttlefish; all active visual predators; all marine; many nektonic, many epifaunal

Arthropods: Insects  Insects – aquatic insect adults & (especially) larvae very common & important in freshwater environments; planktonic, nektonic, epifaunal, infaunal, neustonic, fringing aquatic insects rare in marine environments, all adults; neustonic or fringing

Arthropods: Crustaceans  Decapods – lobsters, shrimps, & crabs; “usually” have 5 pair large legs; freshwater & marine; meroplanktonic marine larvae, nektonic, epifaunal, infaunal, fringing  Isopods – woodlice, fish lice, “isopods”; “usually” have >5 pair large legs; flattened top-bottom; freshwater & marine; epifaunal, infaunal, fringing, a few ectoparasites  Amphipods – scuds, “amphipods”; “usually” have >5 pair large legs; flattened side-to- side; freshwater & marine; a few nektonic, epifaunal, infaunal

Decapods-Isopods-Amphipods

Arthropods: “Micro”-Crustaceans  Copepods – copepods (= “plankton” on Sponge Bob) ; “usually” have 1 eye & swim with enlarged antennae; marine & fresh.; planktonic, a few nektonic, a few epifaunal  Euphausiids – krill; generally resemble decapod shrimps & swim with all their legs; most marine; planktonic, a few nektonic, a few epifaunal  Cladocerans – water fleas; many legs under a covering shell & swim with enlarged antennae; most freshwater; planktonic

Copepods-Euphausiids-Cladocerans

Vertebrates: Chondricthyans  Chondrichthyans – sharks, sting rays, skates, & chimaeras; have cartilaginous skeleton, all consume animal matter; marine & a very few fresh.; nektonic, epifaunal/benthic/dermersal

Vertebrates: Actinopterygiians  Actinopterygiians – most “bony” fishes; have bony skeleton, incredibly diverse; very many marine & very many fresh.; nektonic, epifaunal/benthic/dermersal Teleosts = most species of actinopterygiians

Vertebrates: Amphibians  Amphibians – frogs, salamanders, newts, & caecilians; most have aquatic larvae & some adults remain aquatic, all eat animal matter; all fresh., NO marine; epifaunal/benthic/dermersal, fringing

Vertebrates: Reptiles  Reptiles – Important aquatic subgroups, but ALL must lay eggs (or give birth) on land. epifaunal/benthic/dermersal, nektonic, fringing -Lizards & Snakes – Few lizards, but many snakes aquatic, all eat animal matter; most fresh., Only a few marine (sea snakes) -Turtles – Many aquatic; many fresh & many marine -Crocodilians – ALL aquatic, all eat animal matter; most fresh & a few marine -Birds – Many aquatic; many fresh & many marine (penguins = most aquatic birds)

Vertebrates: Mammals  Mammals – Important aquatic subgroups, most give birth on land. epifaunal/benthic/dermersal, nektonic, fringing -Whales (Cetaceans) – Completely aquatic, all eat animal matter; most marine, Only a few freshwater -Manatees & Dugongs – Completely aquatic, all eat plant matter; most enter both marine & freshwater -Seals & Sea Lions – All aquatic, all eat animal matter; most marine, Only a few freshwater -Otters – All aquatic, all eat animal matter; fresh & marine species -Rodents – A few aquatic, all eat plant matter; all freshwater

Cetaceans  Baleen Whales  Toothed Whales Sperm Whales Dolphins, porpoises, & other toothed whales

Freshwater-vs.-Marine  Larval Stage Planktonic larval stages are largely restricted to marine environments. Freshwater organisms are more likely to have fewer larger offspring to which they provide more care. Why?  Spawning Group open-water spawning is much less common in freshwater environments. Why?  Size Body sizes over 3.5 meters are largely restricted to marine environments. Why?