MARE 171

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Life in the Drink What happens when you mix
Marine with Biology ?
MARE 171 Ms. Jen Turner
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Life in the Drink
Marge? Kids? Everything's going to be just fine.
Now go upstairs, and pack your bags...we're going
to start a new life...under the sea. Homer
Simpson
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Key Concepts
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Key Concepts of the Day

• How Organisms Adapt to Salty Oceans
• How Organisms Adapt to Heat Loss/Gain
• Species of the Day

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Salinity !
Salinity total amount of dissolved material in
one kilogram of sea water Salinity expressed
as 35 ppt or (0/00) New term PSU Practical
Salinity Unit 35 psu (350/00) Dissolved
compounds gt 99.9 inorganic salts Major Cl
(55.0), Na (30.6), SO4 (7.7), Mg (3.7), Ca
(1.2), K (1.1) Minor and trace elements (e.g.
Zn, Cu, Ni, Fe)
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Physiology of Salinity Control

• Inshore vs. offshore pattern of variability
• Inshore (estuarine spp.) challenged tolerate
  both
• Salinity Cellular chemistry (Na, K)?
• chemical reactions can become adversely
  affected
• Affects catalytic rate, enzyme-substrate,
  membrane transport

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Coping With Salinity
Yaahr, Its a good read says I
I hate the sea and everything in it Practical
tips from a salty dog
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Osmoregulation

• An organisms expenditure of energy to regulate
  their internal body salinity, keeping that
  salinity at a fairly stable level

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Some molluscs
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Salinity Osmoregulation

1) Osmosis movement of pure H2O across membrane
(permeable H2O but not to solute )
Osmotic strength?solute concentration
Water moves from area of lower solute
concentration to higher
Lower outside
Equal
Higher outside
More dissolved material (less water) in cell -
water moves into cell
Less dissolved material (more water) in cell -
water moves out of cell
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Body 1/3 solutes of SW.How to maintain osmotic
homeostasis
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How to Maintain Osmotic Homeostasis
Freshwater Teleosts (bony fishes)
Water gain by osmosis gills and skin
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Does not Drink
Salts pass through gut
Chloride Cells Selective absorption of salts
(Mg2 SO42-) at gills
Excrete dilute urine Large volume
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Elasmobranchs
Increase solute concentration in body (reduce
osmotic pressure)
Synthesis of urea increases solute concentration
Some water salt with food
Isosmotic condition
Excess salts excreted by digitiform or rectal
gland and in urine
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Osmo Kramer
These pretzels are making me thirsty! Kosmo
Kramer
Marine Mammals
Water loss by osmosis
Drink SW
H20
Specialized kidneys concentrate urine to a
greater extent than other mammals Metabolic
water" from food
Excrete concentrated urine
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How to Maintain Osmotic Homeostasis
Human Horses - Single smooth lobe Marine
Mammals - highly subdivided, each reniculus
acting as a miniature kidney
Reniculi
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Salt glands of reptiles and birds
Way to cope with intake of salt (food/water).
Kidneys not very effective? require salt glands
Skull of a sea gull
Skull of a sea turtle
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Gland in the orbit of eyesalty tears
Salt gland empties into nasal cavity
ridge prevents it from being swallowed
they squeeze it out
Salt water crocs? salt glands over surface of
tongue .and they spit it out. Similar strategy
employed by sea snakes
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Salt Gland Powers, Activate
Brian, take out your ring. Wonder Twin powers
activate. Shape of steam. "Peter, we got these
from a box of Frankenberry Peter Brian
Griffin
Sea Turtles When glands activated ? discharges
a fluid 6X that of blood 2X seawater When
inactive ? ¼ the concentrating capability Greater
than marine birds 2X shark rectal gland Unlike
avian glands remove Mg2
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Temperature

• Regulated by solar energy input water mixing
• Primary factor governing life processes
• (e.g metabolism) distribution
• Varies over spatial temporal scales

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Temperature
Polar Temperate (cold warm) Tropical
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Temperature
Varies by depth, region, season
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Temperature Effects

• Chemical reactions depend on temperature
• Metabolic rate doubles approximately every 10º
• Can determine survival of offspring
• Can determine sex of offspring

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Physiological Ecology how to cope w/ temperature
change
Conformer Physiological state
environment Regulator Physiological state
different from environment
Conformer
Body Temp
Regulator
0 10 20 30
Ambient Temp
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Zones of Resistance Compatibility
Encounters stressful condition 1) migrate 2)
adapt, adjust, survive 3) die
Zone of resistance
100 50 0
Zone of resistance
Zone of compatibility
Percent survival
Lower Upper Incipient lethal points
Environmental gradient
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Physiology of Temp Control

• Endothermy internal metabolic production of heat
• Ectothermy depends on environmental heat sources
• Homeothermy stable internal body temperature
• Poikilothermy variable internal body temperature

Ectothermy Endothermy - Mechanisms Homeothermy
Poikilothermy Body Temp Profiles
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Physiology of Temp Control

• Homeotherms
• Poikilotherms
• Heterotherms
• Heliotherms

Endothermy
Ectothermy
Endo Ectothermy
Depend on solar radiation for thermoregulation
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Endothermy in Fishes
Brain heaters in billfish eye brain have
Thermogenic (heat producing) Cells
Still NOT Homeotherms Are Heterotherms (ecto
endo)
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Water 19.3C
Tunas, billfish some mackerel have thermogenic
(heat producing) cells which aids in maintaining
elevated body temps while moving through
environments w/ variable temps
Tuna Core 31.4C
Why Important?
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Advantages to Endothermy
Higher Metabolic Rate More efficient prey
capture Swim faster Better visual
capabilities More efficient digestion More
efficient utilization of food
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Controlling Temp Minimize Heat Loss
Heat Loss 1) Conductance 2) Convection 3)
Radiation (IR) 4) Evaporation
Evaporation
Radiation
Convection
Conduction
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Most birds/mammals spend time in environments
that fall within the TNZ
High constant body temp can be maintained at
rest over a fluctuation of temperatures of 5-10 C
w/ little extra metabolic work?this is the TNZ.
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Lines of Defense maintaining temp
Increase heat production Muscle activity
(exercise) Shivering Brown fatuncouple
phosphorylation Decrease heat loss Insulate
body surface Curling/huddling
Vasoconstriction Counter Current Exchangers
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Counter-Current Heat Exchange
Heat is conserved before it is lost at the
extremity
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Species of the Day
Common Name Hawaiian Domino Damsel Scientific
Name Dascyllus edmondsoni Hawaiian Name
Äloiloi "Bright and Sparkling"