Download Introduction to Marine Life

Introduction to Marine Life
Finally!!!
LAND vs OCEAN
• Ocean is wetter than land
– Materials can be dissolved in ocean water
– gametes can be dispersed more easily
– Harder for smaller things to move through
water
• Ocean is more vast than land
– Harder to find mates and food
• Ocean is more supportive than land
– Body structure will be different than land
animals
• Living in aquatic environment will shape
biology and adaptations of marine life
Some Essential Characteristics of
Life
•
•
•
•
•
•
Made of cells
Getting energy
Growth and development
Reproducing
Respond to environment
Maintaining homeostasis
Naturalseasponge.com
Classification of Living Things
• Taxonomy
• Every organism has a two part name
unique to itself
• Genus species or Genus species
– Prevents confusion if a species is known by
many common names
• There are several ways to classify animals
at higher levels of organization
5 Kingdom Classification
Cellular Differences
• Prokaryotes – Kingdom Moneran / bacteria
group
– Lack a nucleus and membrane bound organelles
• Eukaryotes- All other kingdoms
– Have a nucleus and membrane bound
organelles
http://io.uwinnipeg.ca/~simmons/1116/images/bactloco.gif
http://www.biol.tsukuba.ac.jp/~inouye/ino/etc/dinoflagellates.jpg
FOOD WEBS
• Trophic level… position or feeding level
• Producers…base of the food web and
create sugars from sun’s energy or
chemical energy
• Consumers…eat other living things
• Food webs are the connection between
many food chains in an ecosystem
Marine Food Chain
Apex predators…efficient hunters, opportunistic feeding habits (eat what is available)
(tuna, sharks, billfish)
Higher level consumers…predators that feed on smaller fish in level below
(bluefish or flounder)
Tertiary consumers…predators that feed on smaller fish in level below (bluefish)
Secondary consumers…filter feed out zoo and phytoplankton (silverside or
clam)
Zooplankton…tiny animal life that drift thru the water and graze on plankton (copepod)
Phytoplankton…single celled plant like orgs (diatoms)
10% Rule
• Higher trophic level orgs…larger in size and
fewer in number than those at lower levels.
• each trophic level transfers 10% of its energy
• each level supports a smaller total biomass to
compensate loss of food value.
• 90% loss is used for growth, reproduction,
repair etc…
What Does 10% Rule Mean?
• 100,000 lbs of phytoplankton feed 10,000 lbs of
copepods,
• 10,000 lbs copepods feed 1,000 lbs of
silversides
• 1,000 lbs silversides feed 100 lbs of mackerel
• 100 lbs of mackerel feed 10 lbs of bluefin tuna
• tuna nourishes only one pound of apex predator
OTHER FOOD ROLES
• Decomposers… break down food and
nutrients left over from predation or in
dead orgs or waste
• Omnivores…feed on consumers and
producers
• Microbial loop…bacteria help make
available even smaller nutrients called
DOM (dissolved organic matter) that would
otherwise be lost
Lifestyles of Marine Orgs
• Planktonic
• Nekton
• Benthic
Plankton
• Most biomass on Earth consists of plankton
• Phytoplankton
– Autotrophic (diatoms, coccolithophores)
• Zooplankton
– Heterotrophic
• Bacterioplankton
– The most abundant photosynthetic organism on earth
• Half of all the photosynthetic biomass in ocean
• Virioplankton
– Viruses (mostly attack plankton)
Types of Plankton
• Holoplankton
– Entire lives as plankton
– Ex. copepod
• Meroplankton
– Part of lives as plankton
– Juvenile or larval stages
– Ex. Blue crab
interactive.usc.edu/.../archives/2005/08/
Nekton
• Independent swimmers
Ex…fish, marine mammals
Benthos
• Live on surface of sea floor or buried in
sediments
• Most abundant in shallower water
• Ex. Marine worms, crabs, lobsters
GROWTH and DEVELOPMENT
• Life history…cycle from birth to
reproduction
• Animals often look very different in early
life history from their adult form
• Many marine orgs undergo
metamorphosis dependent on
environmental conditions
• Larval stages are often food for higher
trophic levels
REPRODUCTION
• Animals in marine environment have many
strategies for “success”
• Egg production is “costly” and there are
tradeoffs for each strategy for reproduction
• R-strategy….produce many offspring with
low probability of survival
• K strategy… produce less young but
heavily invested in offspring so higher
chance of survival
More on Reproduction
Specific methods of producing offspring…
• Fission, budding, eggs hatching externally,
eggs hatching internally, live births, some
marine animals are born in freshwater,
some are born on land, etc…
Physical Support
• Phytoplankton example
• Must life in the upper water column. Must remain
buoyant.
• How to resist sinking?...take advantage of water’s
viscosity.
• Be small…more specifically, have a small volume but
larger surface area…think about an ant with a parachute!
• Sinking is a bigger problem in warm water because
warm water is less viscous.
Staying Afloat
• Appendages to increase surface area
• Oil in micro-organisms to increase
buoyancy
• Fewer support
structures in
cold rather than
warm seawater
Physical Support
• Larger orgs (swimmers)
are streamlined
• Flattened / tapered bodies
• Would you rather
be a Ferrari, or a
minivan?
Temperature
• Smaller animals live in warmer seawater
• More appendages in warmer seawater
• Tropical organisms grow faster, live
shorter, reproduce more often
• More diversity in warmer seawater
• Total amount of life is greater in cooler
seawater (lots of nutrients)
Temperature
• Stenothermal
– Organisms withstand small variation in temp
– Typically live in open ocean
• Eurythermal
– Organisms withstand large variation in temp
– Typically live in coastal waters
Salinity
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• 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
Saltwater vs Freshwater Fish
• Need to maintain body water
• Marine fish are at risk of ‘dehydrating’, and
freshwater fish are at risk of having their
cells burst from the uptake of too much
water
RELATIONSHIPS IN THE OCEAN?
How and why organisms interact with one another
CATEGORIES
Interactions between 2 members of
the SAME species
Interactions between 2 members of
DIFFERENT species
Reproduction
Predation
Cannibalism
Parasitism
Mutualism
Competition
A. SAME species
Competition
B. DIFFERENT species
C. BOTH CATEGORIES
A
B
C
D
Interactions
Male-Female…
Female Choice
Who has the
darkest blue
feet?
How many fish do you see?
Male
A. None
B. One
C. Two
How many fish do you see?
A. None
B. One
C. Two
Which one is a barnacle?
A
B
C
E=all of the above
F=some of the above
D
Parasitic Barnacle Life Cycle
lands externally
burrows in
infect new crab
male
female
grows internally:
interna stage
impedes growth
feminizes
grows internally:
interna stage
impedes growth
externa opens
produces externa stage
reproductive replacement..
castration
What is this shrimp doing??
A.
B.
C.
D.
becoming lunch
committing suicide
having lunch
making a mistake
RELATIONSHIPS IN THE OCEAN
Interactions between organisms can
influence the traits and behaviors
of those organisms
Reproduction
Male-Male interactions influence male size
Male-Female interactions influence
male courtship behavior &
traits used in display
male lifestyles
Parasitism
Host-parasite interactions influence
traits parasites use to “control” hosts
behaviors hosts use to avoid parasites…
Mutualism
Interactions that can help some species
avoid other interactions!
• As an organism gets larger
it’s volume increases faster
than it’s surface area.
• The S/V ratio is maximal at
small sizes
• Small S/V ratios help fight
against sinking but are also
best for exchanging gases
and nutrients