Marine Life and Adaptations to the Marine Environment

Marine Life and Adaptations to the Marine Environment

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

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

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

Domain 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

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!!

Now we will talk about Domain Eukarya ○ Includes protists, fungi, plants, animals

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

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)

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

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

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

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

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.

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

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. )

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

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

What are the embryonic tissue layers? Tissue layers that form during development ○ Ectoderm ○ Mesoderm ○ Endoderm

What is radial symmetry? What is bilateral symmetry?

What is an acoelomate? What is a coelomate?

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

Bilaterally symmetrical animals Platyhelminthes – flatworms Protostomes ○ Annelids ○ Mollusks ○ Nematods ○ Arthropods Deuterostomes ○ Echinoderms ○ Chordates

Platyhelminthes – flatworms Class Turbellaria – free-living flatworms Class Trematoda – flukes Class Cestoda - tapeworms http: //ocean. nationalgeographic. com/ocean/photos/marine-worms/#/marine-worms 03 -flatworm_18260_600 x 450. jpg

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

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/view. Marine. Invert. Species. php? invert_marine_id=26

Protostomes Nematoda – round worms ○ Many of these are parasitic

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

Limulus polyphemus Callinectes sapidus

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

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

Vertebrates Class Chondrichthyes Sharks, rays

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

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

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

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)

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

http: //i. ehow. com/images/Global. Photo/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

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

Nekton Independent swimmers Most adult fish and squid Marine reptiles Marine mammals

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

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

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

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

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/aph 162/webpages/dylanandco/lab 1/image

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

Fin designs in fish Vertical fins as stabilizers ○ dosral and anal fins Paired fins for “steering” and balance ○ Pelvic and pectoral Tail fin (caudal) for thrust http: //www. biologycorner. com/resources/fish_fins. gif

Adaptations to marine life Narrow range temperature in oceans Smaller variations (daily, seasonally, annually) Remember it takes longer to change water temp than air temp Deep ocean nearly isothermal

Adaptations to marine life Cold- versus warm-water species Smaller in cooler seawater More appendages in warmer seawater Why? Tropical organisms grow faster, live shorter, reproduce more often Higher # of species in warmer seawater Not necessarily higher # of individuals More biomass in cooler seawater (upwelling) Polar waters are much more productive (more plankton growth) than tropical waters

Adaptations to finding prey Most fish coldblooded but some are warm-blooded Homeothermicbody temperature above sea water temperature Modifications in circulatory system Mainly in fastswimming fish http: //www. sciencedaily. com/images/2005/10/051031133653. jpg

Adaptations of deep-water nekton Mainly fish that consume detritus or each other Lack of abundant food Bioluminescence ○ http: //www. ted. com/talks/edith_widder_glowing_life _in_an_underwater_world. html Fishing lures Large, sensitive eyes Anglerfish w/ males http: //www. antoranz. net/CURIOSA/ZBIOR 2/C 0301 Lanternfish http: //www. lifesci. ucsb. edu/~biolum/organism/pictures/myctophid 1. jpg

Adaptations to marine life Stenothermal Organisms withstand small variation in temperature Typically live in open ocean Eurythermal Organisms withstand large variation in temperature Typically live in coastal waters

Adaptations to marine life Stenohaline Organisms withstand only small variation in salinity Typically live in open ocean Euryhaline Organisms withstand large variation in salinity Typically live in coastal waters, e. g. , estuaries

Adaptations to marine life Extracting minerals from seawater High concentration to low concentration Diffusion Cell membrane permeable to nutrients, for example Waste passes from cell to ocean

Adaptations to marine life Osmotic pressure Less concentrated to more concentrated solutions Isotonic Hypertonic Hypotonic

Adaptations to marine life Dissolved gases Some animals extract dissolved oxygen (O 2) from seawater through gills Fig. 12. 15

Adaptations to marine life Water’s transparency Many marine organisms see well Some marine organisms are nearly transparent to avoid predation

Adaptations to marine life Camouflage through color patterns Countershading Disruptive coloring http: //www. youtube. com/watch? v=Pm. DTtk. Zl Mw. M http: //theplasticocean. blogspot. com/2012_07_01_archive. html

Adaptations to marine life Water pressure Increases about 1 atmosphere (1 kg/cm 2) with every 10 m (33 ft) deeper Many marine organisms do not have inner air pockets Collapsible rib cage (e. g. , sperm whale)

Main divisions of the marine environment Pelagic (open sea) Neritic (< 200 m) and oceanic Benthic (sea floor) Subneritic and suboceanic Another classification scheme: Euphotic Disphotic Aphotic

Pelagic environments – Open ocean Fig. 12. 19 Epipelagic Mesopelagic Bathypelagic Abyssopelagic

Benthic environments – ocean floor Supralittoral Transition from land to seafloor Subneritic (under neritic) Littoral (intertidal zone) Sublittoral (shallow tidal zone to 200 m) Suboceanic Bathyal (200 -4, 000 m) Abyssal (4000 -6000 m) Hadal (below 6000 m) Fig. 12. 19

Distribution of benthic organisms Fig. 15. 1 More benthic productivity when closely beneath areas of high surface primary productivity Mainly on continental shelves Affected by surface ocean currents

Humans and coral reefs Activities such as fishing, tourist collecting, sediment influx due to shore development harm coral reefs Sewage discharge and agricultural fertilizers increase nutrients in reef waters corals thrive at low nutrient levels Phytoplankton overwhelm at high Coral covered with macroalgae nutrient levels, limit light reaching the corals Bioerosion of coral reef by algaeeating organisms http: //daac. gsfc. nasa. gov/oceancolor/images/coral_reef_algae. jpg

Ocean Literacy Principles 3. e - The ocean dominates the Earth’s carbon cycle. Half the primary productivity on Earth takes place in the sunlit layers of the ocean and the ocean absorbs roughly half of all carbon dioxide added to the atmosphere. 5. a - Ocean life ranges in size from the smallest virus to the largest animal that has lived on Earth, the blue whale. 5. b - Most life in the ocean exists as microbes. Microbes are the most important primary producers in the ocean. Not only are they the most abundant life form in the ocean, they have extremely fast growth rates and life cycles. 5 c. - Some major groups are found exclusively in the ocean. The diversity of major groups of organisms is much greater in the ocean than on land. 5. e - The ocean is three-dimensional, offering vast living space and diverse habitats from the surface through the water column to the seafloor. Most of the living space on Earth is in the ocean. 5. f - Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, p. H, light, nutrients, pressure, substrate and circulation, ocean life is not evenly distributed temporally or spatially, i. e. , it is “patchy”. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert. 5. g - There are deep ocean ecosystems that are independent of energy from sunlight and photosynthetic organisms. Hydrothermal vents, submarine hot springs, methane cold seeps, and whale falls rely on chemical energy and chemosynthetic organisms to support life.

Sunshine State Standards SC. 6. L. 14. 3 - Recognize and explore how cells of all organisms undergo similar processes to maintain homeostasis, including extracting energy from food, getting rid of waste, and reproducing. SC. 7. L. 17. 3 - Describe and investigate various limiting factors in the local ecosystem and their impact on native populations, including food, shelter, water, space, disease, parasitism, predation, and nesting sites. SC. 912. L. 15. 5 - Explain the reasons for changes in how organisms are classified. SC. 912. L. 15. 6 - Discuss distinguishing characteristics of the domains and kingdoms of living organisms. SC. 912. L. 17. 2 - Explain the general distribution of life in aquatic systems as a function of chemistry, geography, light, depth, salinity, and temperature. SC. 912. L. 17. 7 - Characterize the biotic and abiotic components that define freshwater systems, marine systems and terrestrial systems.