SKIN COLOR CONTROL OF THE RED-SEA BREAM (PAGRUS-MAJOR)

The effect of different concentration of K+ and Na+ on the skin colour of red sea bream and on melanosome movements in melanophores was inve stigated by using a video microscope system and subsequent image analy sis. Soaking in artificial sea water containing 470 mmol/L NaCl, 10 mm ol/L KCl, 10 mmol/L CaCl2 and 50 mmol/L MgCl2 failed to prevent skin d arkening, while solutions containing over 300 mmol/L KCI instead of th e corresponding amount of NaCl induced aggregation of melanosomes, eff ectively preventing skin darkening. However, soaking in a solution con taining 480 mmol/L KCI diminished the red colour of the fish skin. It is concluded that tile solution containing 300 mmol/L KCl is useful to maintain skin colour of red sea bream and improve its commercial valu e. (C) 1998 Academic Press Limited.