metabolism, energetic demand, and endothermy sara mccutcheon and christine bedore september 25, 2007
DESCRIPTION
Introduction- Muscle Red muscle (RM) v. White muscle (WM) RMWM aerobic/oxidativeanaerobic/glycolytic fast-twitchslow-twitch high-power sustained burst swimming swimmingintermediate sustained swimming RM WMTRANSCRIPT
![Page 1: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/1.jpg)
Metabolism, Energetic Demand, And Endothermy
Sara McCutcheon and Christine BedoreSeptember 25, 2007
![Page 2: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/2.jpg)
Introduction- Respiration
Buccal ventilation
Ram ventilation
Obligate ram ventilation
![Page 3: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/3.jpg)
Introduction- Muscle
Red muscle (RM) v. White muscle (WM)
RM WMaerobic/oxidative anaerobic/glycolyticfast-twitch slow-twitchhigh-power sustained burst swimming swimming intermediate sustained
swimming
RM WM
![Page 4: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/4.jpg)
Introduction- Thermoregulation
Ectothermy
• body temp ~ ambient (Ta)•most elasmobranchs
Endothermy
• body regions > Ta
• local metabolic heat production• muscles, brain, eyes, stomach• cruising, pelagic species (Lamnids and Alopids?)
![Page 5: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/5.jpg)
Introduction- Temperature Coefficient
Q10:
• metabolic rate change/10 C change in T⁰ a
• Q10= (MR1/MR2) (10/T
2-T
1)
![Page 6: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/6.jpg)
Metabolic Rate
Specific Dynamic Action (SDA)
• metabolic cost of digestion/assimilation
• depends on prefeeding energy, starvation time, activity level
• SDAelasmos ~ SDAteleosts: 15%-20% of metabolism
![Page 7: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/7.jpg)
Metabolic Rate
Standard Metablic Rate (SMR)
• MR-SDA of “resting” fish
• species that rest- direct measurement
• obligate ram ventilators-indirect measurement
![Page 8: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/8.jpg)
Metabolic Rate
Ectotherm SMR
• ↓ Ta & ↓activity = ↓ VO2 = ↓ SMR
• ↑ Ta & ↑ activity = ↑ VO2 = ↑ SMR
• highest- obligate ram ventilators
• highest measured= ½ kg, 28 C ⁰ C. acronotus239 mg O2∙ kg-1 ∙ h-1
![Page 9: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/9.jpg)
Metabolic Rate
Batoid SMR
• SMRbatoid ~ SMR<active, cool H2O, similar size sharks
• High Q10: big ∆MR/10 C⁰
behavioral thermoregulation?
cool H2O ↓ energy demand
exploit warm H2O for food
![Page 10: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/10.jpg)
Metabolic Rate
Maximum Metablic Rate (MMR)
• >active species=↑ MMR
• ex: Sphyrna lewini v. Triakis semifaciata
![Page 11: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/11.jpg)
Metabolic Rate
Anaerobic Metabolism
• WM
• powers burst swimming- ectothermsex: Prionace glauca
![Page 12: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/12.jpg)
Metabolic Rate
y-axis= enzyme activity at 20 C⁰
Bernal et al., 2003
![Page 13: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/13.jpg)
MR Study Methods- Respirometry
•VO2= oxygen consumption
• Indirect calorimetry: calculate MR by measuring VO2
measure DO ↓ as consumed
•O2 required for aerobic metabolism, therefore good measure of MR
• SMR
![Page 14: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/14.jpg)
MR Study Methods- Respirometry
•Closed respirometer
1 O2 electrode- measure in sealed recirculating tank
• Open respirometer
2 O2 electrodes- before and after chamber
![Page 15: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/15.jpg)
MR Study Methods- Respirometry
•Circular respirometers
Pros: easy to build affordable
fish can swim freely in circular pattern or rest
![Page 16: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/16.jpg)
MR Study Methods- Respirometry
•Circular respirometers
Cons: unnatural swimming patternabrasions, exhaustion, ↓ O2 across gills
lack of H2O mixing during rest
require motion sensors, don’t know actualactivity level
![Page 17: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/17.jpg)
MR Study Methods- Respirometry
•Circular respirometers
![Page 18: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/18.jpg)
MR Study Methods- Respirometry
•Circular respirometers
![Page 19: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/19.jpg)
MR Study Methods- Respirometry
•Swim tunnel respirometers
closed system
treadmill: swimming velocity controlled by H2O flow
active metabolic rate
Brett-type: SIO, developed by Jeff Grahamlarger sharks (juvenile I. oxyrhinchus)H2O temp also controlled
![Page 20: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/20.jpg)
MR Study Methods- Respirometry
•Swim tunnel respirometers
![Page 21: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/21.jpg)
MR Study Methods- Respirometry
•Swim tunnel respirometers
Pros: good for ram ventilators
Cons: requires induction of swimmingstress- handling, confinement
![Page 22: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/22.jpg)
MR Study Methods- Biotelemetry
•Field studies possible
• For accurate measurements, combine lab and field studies
• acoustic telemetry: in lab or fieldphysiological sensors: Tm, HR, vswim, tail beatfrequency (TBF)
then calculate MR
![Page 23: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/23.jpg)
MR Study Methods- Biotelemetry
![Page 24: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/24.jpg)
MR Study Methods- Biotelemetry
•Muscle Temperature telemetry (Tm)
harpoon thermistor deep in epaxial RM
measure ∆ Tm as transmitter pulse rate changes
simultaneously measure depth and Ta
![Page 25: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/25.jpg)
MR Study Methods- Biotelemetry
•Heart Rate (HR) telemetry
Measure HR using EKG to estimate VO2, then calculate MR
Ectotherms: HR↑ linearly with vswim & HR varied with VO2
- not good indicator of MR
modulate stroke volume more than HR
Endotherms: cardiac physiology ~ birds, mammals
maybe can use HR telemetry
![Page 26: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/26.jpg)
MR Study Methods- Biotelemetry
•Swim Velocity (vswim) telemetry
speed sensing transmitters
used by Gruber, Bushnell, & colleagues in the 80s lab and field studies- Negaprion brevirostris
used vswim to calculate MR
1st field derived energy budget for any elasmo
![Page 27: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/27.jpg)
MR Study Methods- Biotelemetry
•Tail Beat Frequency (TBF) telemetry
TBF ↑ with vswim ↑, so reliable indicator of acitivity/MR
Electromyography (EMG)- most common method
Magnetic pivoting vane- as caudal peduncle moves,
vane passes over switch that counts TB
![Page 28: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/28.jpg)
Why study MR and energetics?
•Answer important ecological questions
impact of organisms on their environmentimpact of environment on organism’s survival
• Example: Chris Lowe’s S. lewini studies in Kane’ohe Bay
Determined energy budget for population
S. lewini pups are predominant predator inKane’ohe Bay
![Page 29: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/29.jpg)
Why study MR and energetics?
•Lab studies: (Lowe, 2001)Brett-type swim tunnel respirometer
determined VO2/TB
linear relationship
![Page 30: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/30.jpg)
Why study MR and energetics?•Field studies: (Lowe, 2002)
tracked pups in the bay with TBF acoustic transmitters
determined normal TBF
![Page 31: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/31.jpg)
MR Study Methods- Biotelemetry
•Lab studies + field studies = energy budget
C=M+W+G
C=consumption
M=metabolism
W=waste
G=growth
![Page 32: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/32.jpg)
MR Study Methods- Biotelemetry
•Lab studies + field studies = energy budget
• Simplified data for an average pup (760g, 26⁰C)
M= 72 kJ/day
W= 27% of C
G= 18g/day
Therefore, C=242 kJ/day
![Page 33: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/33.jpg)
MR Study Methods- Biotelemetry
•Application:S. lewini pups- major predator in Bay
huge demand on ecosystem
water temp↑ in summer = MR↑ in summercal content of primary prey is low MR↑ + ↓ cals = ↑ mortality in summer
water temp ↓ in winter = MR ↓ in winter ↑ G, ↓ competition
so- ↓ prey= ↓ S. lewini population?
![Page 34: Metabolism, Energetic Demand, And Endothermy Sara McCutcheon and Christine Bedore September 25, 2007](https://reader036.vdocument.in/reader036/viewer/2022062412/5a4d1af17f8b9ab05997e60c/html5/thumbnails/34.jpg)
Literature CitedBlock, B.A., and F.G. Carey. 1985. Warm brain and eye temperatures in sharks.
J. Comp. Physiol. B. 156: 229-236.
Carlson, J.K., K.J. Goldman, and C.G. Lowe. 2004. Metabolism, energetic demand,and endothermy. Pp. 203-224 in Biology of Sharks and Their Relatives.(J.C. Carrier, J.A. Musick, and M.R. Heithaus, eds.). CRC Press, Boca Raton
Goldman, K.J. 1997. Regulation of body temperature in the white shark, Carcharodon carcharias. J. Comp. Physiol. B. 167: 423-429.
Lowe, C.G. 2001. Metabolic rates of juvenile scalloped hammerhead sharks (Sphyrnalewini). Marine Biology 139:447-453.
Lowe, C.G. 2002. Bioenergetics of free-ranging juvenile scalloped hammerheadsharks (Sphyrna lewini) in Kane’ohe bay, Oahu, HI. J. Exp. Marine Biol.Ecol. 278:141-156.
Wolf, N.G., P.R. Swift, and F.G. Caery. 1988. Swimming muscle helps warm the brain oflamnid sharks. J. Comp. Physiol. B. 157: 709-715.