Marine Life and Adaptations to the Marine Environment
Dec 19, 2015
Classification of living organisms
Three domains of Three domains of LifeLifeArchaea
Prokaryotic, includes “extremophile” bacteria
Bacteria Prokaryotic, includes
what used to be in Kingdom Monera
Eukarya 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 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!!
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
FungiHeterotrophic
Secrete enzymes and absorb nutritionSince they are heterotrophic, they are more closely
related to animals than to plants
Multicellular (mold) or unicellular (yeast)
Domain Eukarya
PlantsAutotrophic, multicellularMany plant species cannot tolerate saltwater ○ Very few species grow in/near ocean
Sea grassesMangrovesDune plants
Domain Eukarya
AnimalsHeterotrophic, multicellular, have
motility at some point in life cycleWide 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 unitPopulation 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.
Kingdom Plantae○ Nonvascular Plants – mosses, etc○ Vascular Plants
Seedless Vascular Plants – ferns, etcSeed Vascular Plants- Gymnosperms – “naked” seeds- Angiosperms – flowering plants (in the
marine environment these include mangroves, sea grasses, etc.)
Kingdom AnimaliaParazoa – no true embryonic tissues○ Sponges
Eumetazoa – true embryonic tissues○ 2 true tissues – radial symmetry; Cnidarians,
Ctenophores○ 3 embryonic tissues – bilateral symmetry; all
other animalsAcoelomate – only flatwormsCoelomates:- Protostomes- Deuterostomes
Radially Symmetrical Animals, 2 true embryonic tissuesCnidarians○ 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
Bilaterally symmetrical animals are divided into 2 groupsProtostomes – 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
Bilaterally symmetrical animalsPlatyhelminthes – flatwormsProtostomes○ Annelids○ Mollusks○ Nematods○ Arthropods
Deuterostomes○ Echinoderms○ Chordates
Platyhelminthes – flatwormsClass Turbellaria – free-living flatwormsClass Trematoda – flukesClass Cestoda - tapeworms
http://ocean.nationalgeographic.com/ocean/photos/marine-worms/#/marine-worms03-flatworm_18260_600x450.jpg
Protostomes Mullusca
Class Polyplacaphora - chitinsClass Gastropoda – snails, conchsClass Bivalvia – oysers, scallopsClass Cephalopoda – squid, octopus
Protostomes
AnnelidaClass Oligochaeta – earthwormsClass Polychaeta – many marine
species, sand worms, feather dustersClass Hirudinea - leeches
Marine feather duster worm
http://www.aquariumdomain.com/viewMarineInvertSpecies.php?invert_marine_id=26
Protostomes Arthropoda
Largest group of animals on the planet!!!!Chelicerates – horseshoe crabs and arachnidsCrustaceans – marine and freshwater, crabs,
lobster, shrimp, barnaclesInsects and relatives
Deuterostomes
EchinodermataAdults have pentahedral symmetry but
larvae are bilaterally symmetricalClass Ophiuroidea – brittle starsClass Echinodea – sea urchinsClass Holothuroidea – sea cucumberClass Crinodea – sea lillies
Sea cucumber from IRL
Deuterostomes Chordata
Characteristics: dorsal hollow nerve cord, notochord, post-anal tail, pharyngeal gill slits
Subphylum Urochordata – tunicatesLarvae have bilateral symmetry, look like tadpole
Subphylum Cephalochordata – lancelets Subphylum Vertebrata
○ Superclass Agnatha – jawless fishes○ Superclass Gnathostoma – jaws
Class ChondrichthyesClass OsteichthyesClass AmphibiaClass ReptiliaClass Mammalia
Vertebrates Class Osteichthyes
Bony fish, ray-finned fishGreat diversity in the ocean!○ Very small to very large○ Large tuna, grouper, sailfish○ Deep sea fish○ Flattened fish – flounder○ Seahorses○ Eels
Vertebrates
Class ReptiliaIncludes birds now!!!Sea turtles, sea snakes, pelicans,
penguins, osprey, sea gulls
Vertebrates Class Mammalia
What are the characteristics of mammals?Carnivores: Sea otters, Polar bears, pinnepeds
(walruses, seals, sea lions)Sirenians: manateesCetacea○ 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 PlanktonPlankton (floaters) NektonNekton (swimmers) BenthosBenthos (bottom dwellers)
Plankton
Most biomass on Earth consists of plankton PhytoplanktonPhytoplankton
Microscopic algae, Autotrophic ZooplanktonZooplankton
Heterotrophic Protozoans, tiny animals, larvae of larger
animals Bacterioplankton Bacterioplankton VirioplanktonVirioplankton
Viruses that infect bacteria and eukaryotic cellsViruses that infect bacteria and eukaryotic cells
http://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpg
Plankton o HoloplanktonHoloplankton
o Entire lives as planktono Example is algae, protozoans, small
microscopic animalso MeroplanktonMeroplankton
o Part of lives as planktono Juvenile or larval stages in the planktono Examples are lobsters, some fish species, etc.
o MacroplanktonMacroplanktono Large floaters such as jellyfish or Sargassum
o PicoplanktonPicoplanktono Very small floaters such as bacterioplankton
Benthos
EpifaunaEpifauna live on surface of sea floor
InfaunaInfauna live buried in sediments
NektobenthosNektobenthos 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
BuoyancyHow to resist sinkingDifferent 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
http://www.rpgroup.caltech.edu/~natsirt/aph162/webpages/dylanandco/lab1/image
Fish egg with oil droplet
Fig. 12.9
Adaptations to marine life Streamlining important for
larger organisms Less resistance to fluid
flow Flattened body Tapering back end –
fusiformfusiform
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 seawaterMore appendages in warmer seawater
Why?
Tropical organisms grow faster, live shorter, reproduce more often
Higher # of species in warmer seawaterNot 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 cold-blooded but some are warm-bloodedHomeothermic-
body temperature above sea water temperature
Modifications in circulatory system
Mainly in fast-swimming 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
http://www.lifesci.ucsb.edu/~biolum/organism/pictures/myctophid1.jpg
Lanternfish
http://www.antoranz.net/CURIOSA/ZBIOR2/C0301
Anglerfish w/ males
Adaptations to marine life StenothermalStenothermal
Organisms withstand small variation in temperature
Typically live in open ocean EurythermalEurythermal
Organisms withstand large variation in temperature
Typically live in coastal waters
Adaptations to marine life StenohalineStenohaline
Organisms withstand only small variation in salinity
Typically live in open ocean EuryhalineEuryhaline
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
DiffusionDiffusionCell membrane permeable to nutrients,
for exampleWaste passes from cell to ocean
Adaptations to marine life Osmotic pressureOsmotic pressure Less
concentrated to more concentrated solutions
IsotonicIsotonic HypertonicHypertonic HypotonicHypotonic
Adaptations to marine life Dissolved gases Some animals extract dissolved oxygen
(O2) 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=PmDTtkZlMwM
http://theplasticocean.blogspot.com/2012_07_01_archive.html
Adaptations to marine life Water pressure
Increases about 1 atmosphere (1 kg/cm2) 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
PelagicPelagic (open sea)Neritic (< 200 m) and oceanic
BenthicBenthic (sea floor)Subneritic and suboceanic
Another classification scheme: EuphoticEuphotic DisphoticDisphotic AphoticAphotic
Pelagic environments – Open ocean
EpipelagicEpipelagic MesopelagicMesopelagic BathypelagicBathypelagic AbyssopelagiAbyssopelagi
cc
Fig. 12.19
Benthic environments – ocean floor SupralittoralSupralittoral
Transition from land to Transition from land to seafloorseafloor
Subneritic Subneritic (under (under
neritic)neritic)
Littoral Littoral (intertidal zone)(intertidal zone)
Sublittoral Sublittoral (shallow (shallow
tidal zone to 200m)tidal zone to 200m)
SuboceanicSuboceanicBathyal Bathyal (200-4,000m)(200-4,000m)
Abyssal Abyssal (4000-6000m)(4000-6000m)
Hadal Hadal (below 6000m)(below 6000m)
Fig. 12.19
Distribution of benthic organisms
More benthic productivity when closely beneath areas of high surface primary productivity Mainly on continental shelves Affected by surface ocean currents
Fig. 15.1
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
nutrient levels, limit light reaching the corals
Bioerosion of coral reef by algae-eating organisms
http://daac.gsfc.nasa.gov/oceancolor/images/coral_reef_algae.jpg
Coral covered with macroalgae
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.
5c. - 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, pH, 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 only 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.