Respiration, Circulation and Metabolism

1
Respiration, Circulation and Metabolism

• Circulatory system
• Gills and Oxygen uptake
• Thermal regulation

2
Scombridae Bigeye tuna Thunnus obesus
3
Deep Scattering Layer Diel Vertical Migrators
4
Circulatory System
5
(No Transcript)
6
(No Transcript)
7
Properties of Water Related to Exchange of Gases

• Water contains 1 O2 by volume, whereas air
  contains 21 O2 by volume
• Concentration of O2 dissolved in water varies
  inversely with temperature and salinity
• Salting out effect
• High water temperature Low O2 concentration
• CO2 is very soluble in water because it undergoes
  partial disassociation and forms a weak chemical
  bond with water (H2O CO2 H HCO3- H2CO3)

8
Ventilation and Respiration

• Aerobic Respiration
• O2 CH2O ? CO2 H2O ENERGY
• Ventilation process of directing oxygenated
  water through blood capillary beds
• Diffusion Passive transport of O2 from water
  across epithelial cells and into the capillaries
  containing blood
• CH2O ? Lactate energy ANAEROBIC RESPIRATION

9
Lamprey
Shark
Teleost
10
Ventilation unidirectional flow of water.
11
Gill Lamella
Counter current flow between blood and water
maximizes exchange between fluids.
12
Counter current systems

• If fluids flowed in same direction exchange would
  be about 50, regardless the length of the flow
  systems.
• With counter current flow exchange is more
  complete and varies directly with length of the
  flow systems.

13
(No Transcript)
14
Thermal regulation control of body temperature

• Body temperature of animals relative to that of
  the environment
• Poikilotherms
• Homeotherms
• Source of animals body heat
• Ectotherms
• Endotherms

15
Mechanisms of thermal regulation in fishes

• behavioral
• physiological (endothermy)

16
Behavioral thermoregulation
17
Physiological thermoregulation (endothermy)
Lamnidae Mako Isurus oxyrinchus
18
Physiological thermoregulation (endothermy)
Alopiidae Thresher shark Alopias superciliosus
19
Physiological thermoregulation (endothermy)
Scombridae Bigeye tuna Thunnus obesus
20
Forms of Endothermy

• Systemic or whole body endothermy
• Lamnidae, Alopiidae, Scombridae
• Regional endothermy refers to maintaining
  elevated temperatures only in certain parts of
  the body
• cranial endothermy (brain heaters)
• Istiophoridae, Xiphiidae

21

• Cranial endothermy
• (brain heaters)
• Billfishes (Istiophoridae)

22
Cranial endothermy (brain heaters)
Xiphiidae Swordfish Xiphias gladius
23
Systemic (whole body) endothermy
Shared presence of streamlined body narrow
caudal peduncle crescent-shaped caudal fin
24
Atlantic Bluefin tuna (Thunnus thynnus)
Block et al. 2002
Muscle Temp 28 30 oC / Water temperature -
20 oC
25
Scombridae Bigeye tuna Thunnus obesus
26
Deep Scattering Layer Diel Vertical Migrators
27
Structures and functions involved in systemic
endothermy

• Distribution of blood vessels
• Distribution of red muscle (used for sustained
  swimming, heat generating)
• Rete mirabile (heat exchanger)

28
Distribution of blood vessels
Ectotherm
Endotherm
29
Distribution of red muscle and blood vessels in
cross-section
Bluefin tuna
Ectotherm
Red muscle
Mako shark
Skipjack tuna
30
(No Transcript)
31
Distribution of red muscle and blood vessels in
cross-section
Bluefin tuna
Ectotherm
Red muscle
Mako shark
Skipjack tuna
32
(No Transcript)
33
Heat exchanging retia mirabile of tuna.
34
(No Transcript)