paper presentatn

8/7/2019 Paper Presentatn

1/16

1


2/16

Title: Temperature Influence on Post-prandial Metabolic Rateof Sub-Antarctic Teleost Fish

Authors: Fabin Alberto Vanella, Claudia C. Boy, Mara EugeniaLattuca, Jorge Calvo

Published in: Comparative Biochemistry and Physiology, Part A156 (Feb, 2010) 247-254

2


3/16

To study the influence of temperature on the

energetic cost of food assimilation of four speciesof sub-Antarctic teleost.

3


4/16

Species selected for study-Paranotothenia magellanica,

-Patagonotothen sima

-Harpagifer bispinis

-Austrolycus depressiceps

General techniquesFish collectionAcclimatizationParameters-Photoperiod: 12h dark/12h light-Salinity: 30%

-Temperature: 10oC, 4oC and 2oC

-O2 saturation: 80%Individual respirometric chamber (O2 consumption)

Experimental food items;-Hake (P. magellanica)

-Isopod (P. sima, H. bispinis, A. depressiceps)-Amphipod (H. bispinis)

4Continue


5/16

5Continue


6/16

MEASUREDMEASURED VARIABLESVARIABLESBaseline: Metabolic rate of postabsorptive individuals, quantified as routine

oxygen consumption (mg O2/kg/h).

Peak: Post-prandial peak in metabolism, quantified as oxygen consumption (mgO2/kg/h).

Scope: Post-prandial peak divided by Baseline.

Duration: Time from feeding when metabolic rate is no longer greater thanBaseline values (h).

Meal Size: Wet mass of ingested food as percentage of Body Mass.Meal Energy: Meal Energy determined by bomb calorimetry (kJ).

SDA: Accumulated energy expended above Baseline for Duration of SDAresponse. It is calculated as caloric equivalent (1 mg O2: 14.06 J; Johnston andBattram, 1993) of additional oxygen consumed after a single feeding (kJ).

M

eal Energy/g and SDA/g: In order to compare assimilation cost in differentspecies, Meal Energy and SDA were standardized according to Body Mass.

SDA Coefficient: calculated as the percentage of ingested energy used overroutine values during the SDA process. Gives proportion of ingested energyinverted in SDA.

Q10: Temperature Coefficient, calculated using the formula

Q10=(SDA Coeff.2/SDA Coeff.1)10 / (t2t1)6


7/16

7


8/16

8ContinueContinue


9/16

9Continue


10/16

10Continue


11/16

11Continue


12/16

Temperature and SDA Process

No influence of temperature on Meal Size and Meal Energy

Similar lack of difference was observed by Johnston and Battram (1993).

However, Jobling (1994) reported a direct relationship between temperature

and feeding rate.

Rise in O2 consumption after meals reach 2-3 times, independent of baseline.Johnston and Battram (1993) reported same results. In coincidence, Willmer

et al. (2000) assert that the rise in the oxygen consumption caused by ingestion

is independent of the body temperature of fish.

SDA coefficient shows declining trend with decrease in temperature.Similar drop is reported by Guinea and Fernandez (1997) and by Johnston and

Battram (1993).

Duration shows negative correlation with temperature.

Analysis of published data showed similar results.

12Continue


13/16

13Continue


14/16

Interspecies Analysis (Sps. Fed With Isopods)

Interspecific differences were evident among the three species and may

indicate variations in energetic strategy. H. bispinis (I) consumes more foodand energy and has high duration and SDA coeff.

This can be explained by a high start-up cost of digestion in this specie (Boice

and Clarke, 1997). Fu et al. (2009) describes a correlation between the

foraging and metabolic characteristics.

H. bispinis Fed With Two Different Items

No difference in meal size; implies that no preference for one type of

crustacean.

Higher SDA Coeff. in H. bispinis (I). Fu et al. (2005) reported that SDA

Coeff. did not vary with meal size. It may be attributed to difference inenergy density of crustaceans.

Isopod 10.31 kJ/g

Amphipods 16.96 kJ/g

14


15/16

Decrease in temperature diminish the metabolic cost and extends

SDA, consequence, decrease in SDA Coeff. The SDA Coeff. decrease

could be a way to improve the efficiency of transforming ingested

energy into live tissue at low temperatures when the food

acquisition capacity is limited.

Its the natures mechanism to compensate the less availability of

food, but when applied to aquaculture can give us more energy

directed toward growth and hence more production.

15


16/16

16

paper presentatn

Documents