Critical partial pressures
of oxygen causing precocious hatching in Coregonus lavaretus and C.
albula embryos
P. Czerkies, P. Brzuzan, K. Kordalski, M.
Luczynski-2001
Aquaculture, 196(1-2), 151-158
Abstract:
Embryos of whitefish (Coregonus lavaretus) and
vendace (C. albula) were exposed to various hypoxic conditions at
constant temperatures of 8°C and 11°C at the developmental stages of
"eye movement visible" and "first embryos hatched".
Eggs exposed to hypoxia responded with precocious
hatching and the response depended on the degree of hypoxia, test
temperature, and developmental phase. The calculated critical partial
pressures of oxygen (pO2) causing precocious hatching at 8°C
were 40 mm Hg (3.0 ppm dissolved oxygen concentration DO) for whitefish and
28 mm Hg (2.1 ppm DO) for vendace embryos. The sensitivity of embryos to
hypoxic stress increased rapidly as development progressed. Eventually, the
critical pO2 for vendace eggs increased to 81 mm Hg (6.0
ppm DO) at the stage of "first embryos hatched".
Higher temperatures caused stronger response of
embryos to hypoxia: exposure of whitefish embryos for 60 min to pO2
of 3 mm Hg (0.2 ppm DO) at 8°C resulted in hatching of 43% of eggs, whereas
at 11°C, hatching increased to 95% (at the same oxygen concentration).
Adequate DO concentrations must be provided in
incubation to prevent early hatching and increased mortality.
(Department of Fish Biology and Culture, Olsztyn
University, Oczapowskiego Street 5, 10-718 Olsztyn-Kortowo, Poland, Email of
M. Luczynski: mirekl@uwm.edu.pl)