TITLE:
Short-Term Stress Response of Juvenile Rainbow Trout Subjected to Two Different Rearing Densities
AUTHORS:
Jaid Freestone, Jill M. Voorhees, Nathan Huysman, Eric Krebs, Michael E. Barnes
KEYWORDS:
Rainbow Trout, Density, Feeding, Glucose, Hematocrit
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.13 No.1,
January
12,
2023
ABSTRACT: Juvenile rainbow trout Oncorhynchus mykiss were subjected to one of four treatments in a two-by-two experimental design: 1) fed at a density of
1.8 g/m3, 2) Fasted at 1.8 g/m3, 3) fed at 30.1 g/m3,
and 4) fasted at 30.1 g/m3. Blood glucose and hematocrit were
measured at 4, 6, 48, 168, and 336 hours after placement in one of the two
rearing densities, with relative fin lengths and organosomatic indices recorded
at 336 hours. Glucose levels over time were not significantly different among
the density and feeding treatments. Hematocrit
levels over time were also not significantly different. Total lengths,
weight, hepatosomatic index, viscerosomatic index, and any of the relative fin
lengths were not significantly different between the high and low densities.
However, the hepatosomatic index was significantly greater in the fed fish
compared to those fasted. The splenosomatic index was significantly greater in the
higher density treatment. These results likely indicate no short-term stress
response to the higher rearing density used in this short-term experiment and
no interaction between starvation and density-related stressors.