THE INTERACTION AMONG AGE, THERMAL-ACCLIMATION AND GROWTH-RATE IN DETERMINING MUSCLE METABOLIC CAPACITIES AND TISSUE MASSES IN THE THREESPINE STICKLEBACK, GASTEROSTEUS-ACULEATUS
H. Guderley et al., THE INTERACTION AMONG AGE, THERMAL-ACCLIMATION AND GROWTH-RATE IN DETERMINING MUSCLE METABOLIC CAPACITIES AND TISSUE MASSES IN THE THREESPINE STICKLEBACK, GASTEROSTEUS-ACULEATUS, Fish physiology and biochemistry, 13(5), 1994, pp. 419-431
Thermal acclimation may directly modify muscle metabolic capacities, o
r may modify them indirectly via effects upon physiological processes
such as growth, reproduction or senescence. To evaluate these interact
ing effects, we examined the influence of thermal acclimation and accl
imatization upon muscle metabolic capacities and tissue masses in 1+ s
tickleback, Gasterosteus aculeatus, in which confounding interactions
between temperature and senescense should be absent. Furthermore, we e
xamined the influence of thermal acclimation upon individual growth ra
te, muscle enzyme levels and tissue masses in 2+ stickleback sampled a
t the beginning of their final reproductive season. For 1+ stickleback
, cold acclimation more than doubles mitochondrial enzyme levels in th
e axial muscle. Thermal acclimation did not change the condition of 1 stickleback at feeding levels which could not maintain the condition
of 2+ stickleback. Compensatory metabolic responses to temperature wer
e not apparent in field acclimatized 1+ stickleback. The growth rate o
f 2+ stickleback was markedly affected by temperature: warm-acclimated
fish generally lost mass even at very high levels of feeding (up to 7
8 enchytraid worms per day) while cold-acclimated fish gained mass. Th
is suggests that warm temperatures accelerate the senescence of 2+ sti
ckleback. Generally, muscle enzyme activities increased with growth ra
te. In axial muscle, the relationships between CS activity and growth
rate differed with acclimation temperature. Independent of the influen
ce of growth rate, CS activities were consistently higher in cold- tha
n warm-acclimated 2+ stickleback, suggesting compensatory increases of
CS activity with cold acclimation.