Thanks to all those who responded to my query on mortality from Alizarin
Complexone marking. I thought a summary of the suggestions re: potential
causes/solutions I received might be of interest.
1) pH fluctuations/when using ALC in fresh water, buffer with something
like sodium bicarbonate
2) undissolved Alizarin powder in immersion tank/dissolve the alizarin
overnight in fresh water, add to tank and leave that overnight with
turbulence (air stone) to dissolve all alizarin.
3) excessive ALC conc/though 200 ppm (=200mg/l) has been used successfully
in many fish spp., some workers have marked successfully with conc. as low
Immersion time does not seem to be much of a mortality factor, as several
workers reported successfully using times as long as 24 hours. Longer
times would seem to necessitate larger immersion tanks. With ALC costing
$15/gram, this could be a concern for large operations.
J. Jasper Lament
Department of Biology,
University of Miami,
Coral Gables, FL
Office Phone: (305) 284-4933
Fax: (305) 284-3039
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