Energy in Aquatic Systems

1. 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

2. 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

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

4. 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.

5. 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.

6. 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.

7. 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.

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

9. 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

10. 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;mostmacrophytes, a few periphyton/epiphyton • Brown Algae= mostly multicell. photosynth. euks. w/various cell walls & brown pigments;mostmacrophytes, a fewperiphyton/epiphyton

11. 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

12. 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

13. “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

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

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

16. 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

17. Decapods-Isopods-Amphipods

18. 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

19. Copepods-Euphausiids-Cladocerans

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

21. 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

22. 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

23. 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)

24. 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

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

26. 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?