Marine Life and Adaptations to the Marine Environment

1. Marine Life and Adaptations to the Marine Environment

2. Overview • More than 250,000 identified marine species • Most live in sunlit surface seawater

3. Classification of living organisms • Three domains of Life • Archaea • Prokaryotic, includes “extremophile” bacteria • Bacteria • Prokaryotic, includes what used to be in Kingdom Monera • Eukarya • Eukaryotic cells • Includes Protists, Fungi, Plants, and Animals

4. Domain Archaea • Bacteria - Prokaryotic cells • Cell wall differs from those bacteria in Domain Bacteria • Includes extremophile bacteria • Acidophiles • Halophiles • Thermophiles • Etc. • These bacteria are found to chemosynthesize in hydrothermal vents

5. Domain Bacteria • Bacteria – prokaryotic cells • Cell wall made of peptidoglycan • Includes Staphylococcus, Bacillus, Vibrio, Pseudomonas, etc. • Only a very small % of bacteria are pathogenic • Bacteria are very important in things like nitrogen cycle, decomposition, food making, etc. • Cyanobacteria are photosynthetic bacteria

6. Archaea and Bacteria • Most numerous organisms on Earth!! • Think about how much bacteria lives just on you • Viruses are thought to out number bacteria but if you are just talking about “live” organisms then bacteria are the most numerous • Simplest of organisms • But, can live in every thinkable habitat, even those once thought to be unsuitable to life, very successful organisms!!

7. Now we will talk about Domain Eukarya • Includes protists, fungi, plants, animals

8. Domain Eukarya • Protists: • Algae • Photosynthetic • Can be unicellular, colonial, or multicellular • Multicellular - “seaweed” – kelp, sargassum, sea lettuce • Unicellular – phytoplankton, produce majority of oxygen in atmosphere comes from our phytoplankton, can cause red tides (examples are dinoflagellates and diatoms) • Protozoans • Heterotrophic • Unicellular • Amoeba, paramecium

9. Domain Eukarya • Fungi • Heterotrophic • Secrete enzymes and absorb nutrition • Since they are heterotrophic, they are more closely related to animals than to plants • Multicellular (mold) or unicellular (yeast)

10. Domain Eukarya • Plants • Autotrophic, multicellular • Many plant species cannot tolerate saltwater • Very few species grow in/near ocean • Sea grasses • Mangroves • Dune plants

11. Domain Eukarya • Animals • Heterotrophic, multicellular, have motility at some point in life cycle • Wide variety • From simplest of animals (sponges) to most complex (mammals)

12. Viruses • Acellular entities • Are they “alive”??? – many scientists say no • Do not have the machinery for life processes, have to take over host cell • The ultimate “parasites” • Viruses very prevalent in the marine environment

13. Taxonomic classification • Systemized classification of organisms • Kingdom • Phylum • Class • Order • Family • Genus • Species • Fundamental unit • Population of genetically similar, interbreeding individuals

14. With new molecular methods (comparing DNA sequence and amino acid sequences of certain proteins), traditional taxonomy is changing • Taxonomists are discovering new relationships between species • Molecular data gives a clearer picture of relatedness as opposed to the traditional ways of classifying organisms: • Morphology, embryology, behavior, habitat, etc.

15. Let’s take a closer look at Plant and Animal taxonomy

16. Kingdom Plantae • Nonvascular Plants – mosses, etc • Vascular Plants • Seedless Vascular Plants – ferns, etc • Seed Vascular Plants • Gymnosperms – “naked” seeds • Angiosperms – flowering plants (in the marine environment these include mangroves, sea grasses, etc.)

17. Kingdom Animalia • Parazoa – no true embryonic tissues • Sponges • Eumetazoa – true embryonic tissues • 2 true tissues – radial symmetry; Cnidarians, Ctenophores • 3 embryonic tissues – bilateral symmetry; all other animals • Acoelomate – only flatworms • Coelomates: • Protostomes • Deuterostomes

18. Radially Symmetrical Animals, 2 true embryonic tissues • Cnidarians • Class Anthozoa – sea anemones, corals • Hydrozoa – Hydra • Scyphozoa – “jellies” • Ctenophores – no stinging cells, complete gut unlike in the Cnidarians

19. What are the embryonic tissue layers? • Tissue layers that form during development • Ectoderm • Mesoderm • Endoderm

20. What is radial symmetry? • What is bilateral symmetry?

21. What is an acoelomate? • What is a coelomate?

22. Bilaterally symmetrical animals are divided into 2 groups • Protostomes – 1st blastopore that forms during development becomes the mouth • Includes Annelids, Arthropods, Molluscs • Deuterostomes – 1st blastopore that forms during development becomes the anus • Includes the Echinoderms, Chordates

23. Bilaterally symmetrical animals • Platyhelminthes – flatworms • Protostomes • Annelids • Mollusks • Nematods • Arthropods • Deuterostomes • Echinoderms • Chordates

24. Platyhelminthes – flatworms • Class Turbellaria – free-living flatworms • Class Trematoda – flukes • Class Cestoda - tapeworms http://ocean.nationalgeographic.com/ocean/photos/marine-worms/#/marine-worms03-flatworm_18260_600x450.jpg

25. Protostomes • Mullusca • Class Polyplacaphora - chitins • Class Gastropoda – snails, conchs • Class Bivalvia – oysers, scallops • Class Cephalopoda – squid, octopus

26. Protostomes • Annelida • Class Oligochaeta – earthworms • Class Polychaeta – many marine species, sand worms, feather dusters • Class Hirudinea - leeches Marine feather duster worm http://www.aquariumdomain.com/viewMarineInvertSpecies.php?invert_marine_id=26

27. Protostomes • Nematoda – round worms • Many of these are parasitic

28. Protostomes • Arthropoda • Largest group of animals on the planet!!!! • Chelicerates – horseshoe crabs and arachnids • Crustaceans – marine and freshwater, crabs, lobster, shrimp, barnacles • Insects and relatives

29. Limulus polyphemus Callinectes sapidus

30. Deuterostomes • Echinodermata • Adults have pentahedral symmetry but larvae are bilaterally symmetrical • Class Ophiuroidea – brittle stars • Class Echinodea – sea urchins • Class Holothuroidea – sea cucumber • Class Crinodea – sea lillies Sea cucumber from IRL

31. Deuterostomes • Chordata • Characteristics: dorsal hollow nerve cord, notochord, post-anal tail, pharyngeal gill slits • Subphylum Urochordata – tunicates • Larvae have bilateral symmetry, look like tadpole • Subphylum Cephalochordata – lancelets • Subphylum Vertebrata • Superclass Agnatha – jawless fishes • Superclass Gnathostoma – jaws • Class Chondrichthyes • Class Osteichthyes • Class Amphibia • Class Reptilia • Class Mammalia

32. Vertebrates • Class Chondrichthyes • Sharks, rays

33. Vertebrates • Class Osteichthyes • Bony fish, ray-finned fish • Great diversity in the ocean! • Very small to very large • Large tuna, grouper, sailfish • Deep sea fish • Flattened fish – flounder • Seahorses • Eels

34. Vertebrates • Class Reptilia • Includes birds now!!! • Sea turtles, sea snakes, pelicans, penguins, osprey, sea gulls

35. http://seaturtlesofindia.org/?page_id=12

36. Vertebrates • Class Mammalia • What are the characteristics of mammals? • Carnivores: Sea otters, Polar bears, pinnepeds (walruses, seals, sea lions) • Sirenians: manatees • Cetacea • Odontocetes – toothed whales: dolphins, porpoises, sperm whale • Mysticetes: baleen whales: gray whale, right whale, blue whale (largest animal to roam the Earth)

41. Classification in the marine environment by habitat and mobility • Plankton (floaters) • Nekton (swimmers) • Benthos (bottom dwellers)

42. http://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpghttp://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpg Plankton • Most biomass on Earth consists of plankton • Phytoplankton • Microscopic algae, Autotrophic • Zooplankton • Heterotrophic • Protozoans, tiny animals, larvae of larger animals • Bacterioplankton • Virioplankton • Viruses that infect bacteria and eukaryotic cells

43. Plankton • Holoplankton • Entire lives as plankton • Example is algae, protozoans, small microscopic animals • Meroplankton • Part of lives as plankton • Juvenile or larval stages in the plankton • Examples are lobsters, some fish species, etc. • Macroplankton • Large floaters such as jellyfish or Sargassum • Picoplankton • Very small floaters such as bacterioplankton

44. Nekton • Independent swimmers • Most adult fish and squid • Marine reptiles • Marine mammals

45. Benthos • Epifauna live on surface of sea floor • Infauna live buried in sediments • Nektobenthos swim or crawl through water above seafloor • Most abundant in shallower water

46. Number of marine species • More land species than marine species • Ocean relatively uniform conditions • Therefore, less adaptation required, less speciation • Don’t get this fact confused with # of individual organisms • There are fewer different species in the ocean but greater # of individuals • Majority of life on Earth lives in the ocean!! • Diversity in the ocean is high, also – think about different types of fish (seahorses to sharks, for example) • Marine species overwhelmingly benthic rather than pelagic • Most of these will be in shallow coastal benthic areas where there is light and a lot of primary productivity

47. Marine organisms have a lot of adaptations for living in the marine environment • Let’s take a look at some of these adaptations

48. Adaptations of marine organisms • Physical support • Buoyancy • How to resist sinking • Different support structures in cold (fewer) rather than warm (more appendages) seawater • Smaller size http://www.solaster-mb.org/mb/images

49. Adaptations to marine life • Oil in micro-organisms to increase buoyancy • Over-time, if these organisms die and sink to bottom • Can become offshore oil deposits Fish egg with oil droplet Fig. 12.9 http://www.rpgroup.caltech.edu/~natsirt/aph162/webpages/dylanandco/lab1/image

50. Adaptations to marine life • Streamlining important for larger organisms • Less resistance to fluid flow • Flattened body • Tapering back end – fusiform http://www.wissenschaft-online.de/sixcms/media.php/591