Energy in Aquatic Systems Photosynthesis = Traps light energy in

glucose. (= Most important.)

6CO2 + 6H2O + light → C6H12O6 + 6O2

Chemosynthesis = Transfers chemical energy from H2, H2S, or CH4 to energy in glucose (or another organic form)

6CO2 + 6H2O + 3H2S → C6H12O6 + 3H2SO4

Glycolysis + Cell. Respiration = Release energy in glucose in cell. useful from (ATP).

6O2 + C6H12O6 → 6CO2 + 6H2O + ATP

Energy in Aquatic Systems Photosynthesis requires light and CO2.

6CO2 + 6H2O + light → C6H12O6 + 6O2

Photosynthetic organisms also require nitrate (NO3

-) and phosphate (PO4-) 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

phytoplanktonphytobacteria

dissolved organiccompounds (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/ CaCO3 “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?

SpawningGroup open-water spawning is much less common in freshwater environments. Why?

SizeBody sizes over 3.5 meters are largely restricted to marine environments. Why?