Identifiant ATOL:0001661 GM19
Name of Trait: Thermal growth coefficient
Definition: Normalized growth rate using the following formula
TGC = [(W2 exp0.333 - W1 exp0.333) x (degree x days)
-1 1000] to take into
account the size of the animal and the water temperature
variation.
SIMILAR TO: If its appropriate, in connection with other
Identifiant number
MEASUREMENT METHOD:
The thermal growth coefficient (TGC) model has the following
basic form:
Where, T (a constant) is temperature in C; t is time in days; W0
is initial weight and Wt is final
weight (after t days).
Under constant water temperature, TGC is calculated as:
Under variable daily water temperature, the concept of
degree-days is introduced and TGC is calculated as
Where, W0 is initial weight; Wt is final weight (after t days);
is mean daily water temperature and
is the sum of mean daily water temperature over the study
duration period of t days or
degree-days.
MATERIAL (biological, reagents & instrumental):
Weight (accuracy of 0.1 unit)
UNIT AND RANGE OF VALUE:
Temperature in C, time in number of days, weight in g. TGC is a
coefficient hence has no unit.
Range of TGC values (examples) 1.53 to 1.74 (rainbow trout);
1.39 (lake trout); 0.99 (brown trout);
0.98 (chinook salmon); 0.60 to 2.1 for Atlantic salmon.
PARAMETERS TO MEASURE:
Growth rate taking into account the water temperature
variation.
BIBLIOGRAPHIC REFERENCES:
Dumas, A., France, J., Bureau, D.P., 2007. Evidence of three
growth stanzas in rainbow trout (Oncorhynchus mykiss) across life
stages and adaptation of the thermal-unit growth
coefficient. Aquaculture 267, 139-146.
Iwama, G.K., Tautz, A., 1981. A simple growth model for
salmonids in hatcheries. Canadian
Journal of Fisheries and Aquatic Sciences 38, 649-656.
Jauralde, I., Martnez-Llorens, S., Toms, A., Ballestrazzi, R.,
Jover, M., 2011. A proposal for modelling the thermal-unit growth
coefficient and feed conversion ratio as functions of feeding rate
for gilthead sea bream (Sparus aurata, L.) in summer conditions.
Aquaculture Research.
doi:10.1111/j.1365-2109.2011.03027.x.
Jobling, M., 2003. The thermal growth coefficient (TGC) model of
fish growth: a cautionary note.
Aquaculture Research 34, 581584.
Johnston et al., 2007 see
http://www.st-andrews.ac.uk/fmrg/documents/283.pdf
SYNONYMS EXACT:
VF3/GF3
OTHER ASPECTS TO INCLUDE:
TGC is expected to be constant over a certain size range of the
fish, however, its exponent may
vary (Dumas et al., 2007)
RESEARCHER CONTRIBUTION (and date of the last modification):
sa Maria Espmark (NOFIMA) Bendik Fyhn Terjesen (NOFIMA) Ana
Navarro (ULPGC) Marc Vandeputte (INRA) Eric Leclercq (IoA, UoS)
Jaume Prez-Snchez (CSIC)
AQUAEXCEL Project (20/06/13)
Jrme Bugeon & Pierre-Yves Le Bail (10/10/13)
