Digestive capacity and compensatory growth in Atlantic cod (Gadus morhua) |
| |
Authors: | F Bélanger PU Blier J-D Dutil |
| |
Institution: | (1) Département d'Océanographie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec, G5L 3A1, Canada;(2) Département de Biologie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec, G5L 3A1, Canada;(3) Institut Maurice-Lamontagne, Ministère des P^eches et des Océans, 850 route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada |
| |
Abstract: | The objective of this study was to examine whether digestive capacity correlates with growth rate in Atlantic cod (Gadus morhua). Ninety fish (1035±240 g; 478±36 mm) were assigned to one of three treatments: deprived of food for 5 weeks and then re-fed
for 24 days, deprived for 10 weeks and then re-fed for 24 days, or fed for 24 days without deprivation (controls). Three times
a week during feeding, the fish were provided with meals of capelin (Mallotus villosus) in excess. Within each treatment, ten fish were sacrificed before and twenty after the feeding period. The relative masses
of the pyloric caeca, intestine, and white muscle were determined. Cytochrome c oxidase (CCO), citrate synthase (CS), and
nucleoside diphosphate kinase (NDPK) activities were assayed in the pyloric caeca, intestine, and muscle as was trypsin activity
in the pyloric caeca. During the re-feeding period, fish that had been deprived of food for 10 weeks showed compensatory growth,
growing 1.9 times faster than the controls (0.94±0.26 versus 0.50±0.31% body mass ⋅ day−1). Fish that displayed compensatory growth had a lower relative white muscle mass than controls (66.5±4.1% vs. 69.6±7.4%)
while the relative masses of the pyloric caeca (2.21±0.49% vs. 1.78±0.31%) and intestine (0.95±0.20% vs. 0.77±0.15%) were
greater than the controls, suggesting that the sizes of these digestive tissues might correlate with compensatory growth capacity.
Citrate synthase in the pyloric caeca was the only enzyme that showed higher activity during compensatory growth (8.57±0.94 U ⋅ g
tissue−1 compared to 7.13±1.03 U ⋅ g tissue−1 in the control group). This suggests that aerobic catabolic capacity of pyloric caeca could be related to growth capacity
during recovery, possibly via the energetic cost of digestive enzyme synthesis.
This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
Keywords: | citrate synthase cod compensatory growth digestive capacity pyloric caeca trypsin |
本文献已被 SpringerLink 等数据库收录! |
|