1. Chapter 5: Buoyancy and Thermal
Reading Assignment:
Chapter 5: Buoyancy and Thermal
Regulation
bigeye jack
end

2. Hemoglobin--molecule of O2 transport
Structure
protein
monomer in Myxini & Cephalasipdomorphi
tetramer in Gnathostomata (4 polypeptide chains)
 chain similar in coelacanth and tadpole
end

3. Hemoglobin (Hg) cont. Occurrence: erythrocytes (RBCs)
up to 4M RBC/mm3 of blood
RBC’s nucleated in fish
Hg Absent in some species (Channichthyidae) Antarctic ice fish
fish
human
end

4. Some species have more than one type of hemoglobin
Catostomus clarki -- desert sucker has an additional form of pH insensitive Hg
end

5. end

6. Factors affecting blood oxygen affinitypH
pCO2 (partial pressure of carbon dioxide)
end

7. data for winter flounder
Effect of pH on Hg--two components
100 50
pH 8.02
2. capacity
Root
pH 7.47
1.affinity
% Saturation of Hg
data for winter flounder
Bohr 80
160
pO2 mm Mercury
Air saturation
end

8. affinity: strength of attraction of Hg for O2
Bohr effect--decrease in affinity of hemoglobin for O2 due to decreasing pH or increasing PCO2
affinity: strength of attraction of Hg for O2
Root effect--decrease in capacity of Hg for O2 due to decreasing pH or increasing PCO2 (extreme Bohr effect)
capacity: total quantity O2 of that Hg can carry
end

9. more active species tend to have greater Bohr & Root effects
red versus white muscle
myoglobin
perciform
skipjack tuna
lamnid shark
end

10. Advantage of Bohr Effect
blood circulation
Gills
Tissues
pCO2?
pCO2 higher
pCO2 lower
lactic acid?
lactic acid
no lactic acid
pH?
pH lower
pH higher
end

11. Teleost Heart:
atrium
sinus venosus
bulbus arteriosus
ventricle
end

12. Teleost Heart: atrium sinus venosus bulbus arteriosus relax ventricle
end

13. Teleost Heart: atrium sinus venosus bulbus arteriosus contract
ventricle
end

14. Conus arteriosus--Myxini, Ceph., elasmobranchs, gar
to gills
heart
end

15. bulbus arteriosus 60
Pressure (mm merc.)
ventricle
time
end

16. end

17. Buoyancy strategies 1. Low density compounds
2. Lift generated by swimming
3. Reduction of heavy tissues
4. Swim bladder (air bladder)
end

18. 1. Low density compounds:
Substance
Specific Gravity
Bone
2.0
Muscle
1.05
Cartilage
1.1
Freshwater
Saltwater
Lipids
Squalene
0.86
Advantages/disadvantages
end

19. 2. Lift generated by swimming:
thrust
lift
lift
sharks
Advantages/disadvantages
end

20. hammerhead shark
end

21. nurse shark
end

22. sandbar shark
end

23. 3. Reduction of heavy tissues
Eurypharynx pelecanoides
deepwater fishes
Advantages/disadvantages
end

24. umbrella mouth gulper
end

25. umbrella mouth gulper
end

26. 4. Swim bladder low density adjustable most osteichthians
lost secondarily in some species
end

27. Two types of swim bladders:
Physostomous
pneumatic duct
soft-rayed teleosts--herrings, salmonids, catfishes, cyprinids, eels, etc.
Physoclistous
blood/circulatory system
spiney-rayed teleosts--Acanthopterygii, sunfishes, perch, most marine fishes
end

28. Effects of depth on swim bladder volume
pressure increases 1 ATM/10m
swim bladder must be adjustable
Physostomous fishes adjust volume by gulping or spitting air.
mostly shallow water species
gas-spitting reflex
gulp air at surface
end

29. Physoclistous inflation/deflation
circulatory system--source of gases
rete mirabile (wonderful net) --inflation
oval window--deflation
Problem: fish need greater pressure in swim bladder than is achieved by equilibrium with blood gases
end

30. Oxygen equilibrium—swim bladder inflation
hemoglobin O2
gills
swim bladder
water
plasma O2
swim bladder O2
end

31. Counter-current multiplication system
Diagram of basic functional unit
(inflation)
lactic acid
afferent blood
O2heme  pO2
O2heme 1
pO2
pO2
swim bladder
O2heme  pO2 
efferent blood
end

32. Function of Rete Mirabile
1. Hemoglobin saturated with O2 (O2 heme)
plasma O2 low (p O2)
end

33. Counter-current multiplication system
lactic acid
afferent blood
O2heme  pO2
O2heme 1 2
pO2
pO2
swim bladder
O2heme  pO2 
efferent blood
end

34. Function of Rete Mirabile
2. Lactic Acid Secretions
heme dumps O2 to plasma
pO2 diffuses into swim bladder to equil.
end

35. Counter-current multiplication system
lactic acid
afferent blood
O2heme  pO2
O2heme 1 2
pO2
pO2
swim bladder
O2heme  pO2  3
efferent blood
end

36. Function of Rete Mirabile
3. Multiplying effect: pO2 diffuses from efferent capillary to afferent cap.
Longer capillaries yield more efficient exchange of oxygen, higher pressures
end

37. Physoclistous swim bladder
Pressures up to 300 ATM in some deep sea fishes
Gases mostly O2, some CO2 and N2
Guanine crystals in SB wall reduce permeability
Deflation occurs at oval window
dense bed of capillaries on SB wall
gasses diffuse into blood
mucus layer covers window during inflation
end

38. Summary: Diffusion of O2; controlled by structure & function
Relationship O2 bound to hemoglobin versus O2 in plasma
Effect of pH on affinity/capacity of hemoglobin for O2
Counter-current multiplier
length of capillaries
counter-current flow of blood
end

39. End

40. Print next slide for student note-taking
Do not show this slide or next

41. mya
Era
Periods 65
248 ?
590

42. Ardoch Manvel Inkster Grand Forks Hwy 18 I29 Hwy 1 to Johnstown Hwy 81
Forest River
UND Biol. Area
farm house
stop here
tree line
0.5 mi
Turn right on gravel road
just past tree line, go north
for 0.5 mi, turn right on
two-track road just before
Farm house, pass ravine
on left and turn left following
Ravine on the left, stop by chain
link fence compound.
3 mi
Inkster
Hwy 18
Grand Forks