Osmoregulation

Front 1

Fresh Water Elasmobranchs

Back 1

-Rays and a few sharks

-Low blood osmolarity (less urea)

-Less water inflow and lower urine loss

- Can enter and thrive in rivers

Front 2

Anadromous

Back 2

-Migrating up a river from the sea to spawn

Front 3

Anadromous Teleosts

Back 3

-Salmon

-33-40% osmolarity of seawater

-Most tolerate wide range of osmolarities to migrate

Front 4

Why aren't all aquatic animals with gills euryhaline?

Back 4

-Energentically costly

-No point if they live in a constant osmotic environment (everywhere that is not freshwater or shoreline)

Front 5

Saltwater Teleosts Problem

Back 5

-Have a lower osmolarity than seawater = Water loss and solute gain

Front 6

Saltwater Teleosts Solution

Back 6

-Ingest seawater

-Active transport of excess solutes out of gills

-Loss of other solutes through concentrated urine

Front 7

Freshwater Teleosts Problem

Back 7

- Higher osmolarity than environment = water gain and solute loss

Front 8

Freshwater Teleosts Solution

Back 8

-Produce massive amounts of dilute urine

-Reuptake of solutes in the gills via active transport

Front 9

Euryhaline Fish

Back 9

-Excellent adapters to changing osmotic environments (salmon, trout, etc.)

Front 10

Gill adaptations in Euryhaline Fish

Back 10

-Variable expression of solute active transporters

Front 11

Kidney adaptations in Euryhaline Fish

Back 11

-Concentrated urine in seawater (Osmolarity > seawater)

-Dilute urine in freshwater (osmolarity = freshwater)

Front 12

Saltwater Marshes

Back 12

-Highly variable osmolarity but always less than seawater

-20-25ppt during high tide

-1-2ppt after heavy rains

Front 13

Saltwater Marsh Animals and Plants

Back 13

-Must be euryhaline

-Some animals move in and out with the tide

Front 14

Amphibian Locale

Back 14

-Freshwater aquatic or semi-aquatic

Front 15

Amphibians Osmoregulation Problem

Back 15

-Very thin skin is a source of water and solute gain or loss

-Typically gain water through skin

Front 16

Amphibians Osmoregulation Solution

Back 16

Copious amounts of dilute urine

Front 17

Rana pipens

Back 17

-Amphibian can tolerate brackish waters using urea to balance increased salinity

-No true seawater amphibians

Front 18

Marine Reptiles Problems

Back 18

-Eat seawater with prey

-Must lose salt and retain water

Front 19

Marine Reptiles Solutions

Back 19

-Salt Glands Evolutionary Adaptation

Front 20

Salt Gland

Back 20

-Marine reptiles

-Absorption of Na+ from blood into epithelium of gland

-Active transport of Na+ out of gland and into concentrated salt solution

Front 21

Terrestrial Environment

Back 21

-Easy oxygen access = high risk or dehydration

-Many animals require a moist environment

-Most decrease evaporation, limiting access to air movement

Front 22

Terrestrial adaptation

Back 22

-Surface coatings (scales, feathers, hair, dead skin with oil)

-Decreased activity during hottest part of day

-Changes in the structure and function of kidneys

Front 23

Earthworms

Back 23

-Rapidly lose water through skin in dry air

-Risk of drowning if it does not leave burrow during heavy rains

Front 24

Frogs (and other amphibians)

Back 24

-Extensive water loss through skin

-Can lie dormant and store water as urine

Front 25

Snails

Back 25

-Water-impermeable shells

-Water loss can occur, thus they stick to wet environments

Front 26

Arthropods

Back 26

-Insects with rigid skeleton

Front 27

Crustaceans

Back 27

-Mostly aquatic, some terrestrial

-Excellent osmoregulators that can move between environments

Front 28

Aquatic Arthropod Osmoregulation

Back 28

-Produce NH4+ as a waster product

-Requires large volumes of ingested water or loss at gills

-limits access to land

Front 29

Terrestrial Arthropod Osmoregulation

Back 29

-Produce uric acid as a waster product

-Need less water, can tolerate dessication

Front 30

Insects Water Retention

Back 30

-Can retain water extraordinarily

-Exoskeleton wax coating ins impermeable to water

Front 31

Insects Water Gain and Loss

Back 31

-Water loss = evaporation through respiratory surfaces, feces, secretions, urine

-Water gain = Skin, food, metabolism

Front 32

Evaporation in Insects

Back 32

-Trachae are covered with chitin which limits water loss

-Cuticle is permeable to water, underlying layer of wax

Front 33

Insect waste products

Back 33

-Very concentrated uric acid urine

-Requires a different type of kidney capable of producing a very concentrated urine

Front 34

Water Uptake

Back 34

-Active transport

-Drinking

-Food

-Metabolic

-Via body surface