When the guy from Thailand (who should know what he is talking about) made these comments about the color differences between male and female Dats, I presume that this was based upon the dissection of many fish as a prelude to cooking and eating them. Assuming this information is accurate, I am now wondering if many of those STs that we refer to as "unstable" (and hence, less desirable) are actually FEMALES. If so, we have all been working dilligently to stock our Dat tanks with only males. No wonder we can't get them to breed in captivity.