Comparison
of stress responses in wild and captive winter flounder (Pseudopleuronectes
americanus Walbaum) broodstock
S. Plante, C. Audet, Y. Lambert, J. de la Noüe-2003
Aquaculture
Research, 34(10):
803
Abstract:
Chronic
stress is responsible for many problems occurring in fish holding
facilities, such as increased susceptibility to disease, reduced growth rate
and suppression of the immune response. The goal of this study was to verify
if wild winter flounder (Pseudopleuronectes americanus Walbaum)
suffer from chronic stress when kept several months in captivity. We
hypothesized that winter flounder not subjected to chronic stress in
captivity would have similar or higher condition indices and similar stress
response compared to fish from the wild. Our results showed that the
condition index of winter flounder kept in captivity was higher (1.50) than
those from the wild (1.33) even after one year of captivity. The intensity
of the acute stress response following short-term exposure to air was
similar between wild and captive fish (no significant interaction between
the factors 'stress' and 'origin of the fish'). Body water content (an
indicator of energy reserves) was lower (76.1%) compared to wild fish
(79.8%) after one year of captivity, suggesting that the winter fast had
been less energetically demanding in captive fish. These results indicate
that no chronic stress was present in captive fish. On the other hand, the
mortality during captivity was around 30%, which is high for the aquaculture
industry. Further work to address this problem is required.
(Institut
des Sciences de la Mer de Rimouski (ISMER), Université du Québec à
Rimouski, Rimouski (QC) Canada G5L 3A1. E-mail of C. Audet: celine_audet@uqar.qc.ca)