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
as 25ppm

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
33124-0421

Office Phone: (305) 284-4933
Fax: (305) 284-3039

E-mail:
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