The Quality of Marks Obtained under Different Regimes of Salmon Otolith Marking

摘要

The method of creating otolith marks using specific regimes of rearing water temperature, feeding and photoperiod has been described in many works (including Brothers 1984, 1985; Volk et al. 1987; Brothers 1990; Akinicheva and Rogatnykh 1997). This method allows the creation of marks during the period of juvenile growth in the hatchery, and has been used for the purpose of identification of large managed stocks of fish produced by artificial reproduction. Thermal marks have been created through rearing the embryos and larvae under the temperature that are periodically different from the background, i.e. from water temperature supplied before the time of marking. Decreased water temperature results in slowing down calcium metabolism in fish creating a clear dark stripe.