(re: confirm or deny the studies of Romer and Beisenherz) By the way, the previous studies are still valuable and have contributed to this topic greatly. Although Romer and Beisenherz failed to show the effect of pH, it is still consistent with the findings of Rubin. And I am pretty sure that the environmental effects on sex ratios are replicable, even in the case of Rubin (using one brood each). My work simply contributes to theirs, and builds on theirs. Due to space and funding constraints, I too am unable to provide more replicates per treatment than one other. I hope to use two broods per tank, 8 tanks, 4 conditions. The mixing of broods will make it unlikely that there is a genetic predisposition. The four treatments are (high pH/ high temp), (high pH/ low temp), (low pH/ high temp), (low pH/ low temp). each condition with two tanks, containing two broods each. There are no intermediate values, since I am really testing for interaction (which is a more important sex determinant?). The importance of my study is that pH and temp interaction hasn't been done, and that I try to link between environmental sex determination and behavioural ecology. Although I cannot go with many replicates, it shows that this environmental sex determination by pH and sex is replicable across studies (Rubin, Romer and Beisenherz, mine). The ideal study would have 3 to 4 replicates per treatment, treatments would include 3 pH values and 3 temperature values, with ANOVA testing for interaction. That would mean that there are 9 treatment conditons, with three to four replicates. Alot of money and effort is needed to rear 36 to 45 tanks of Apistogramma, but that would be a perfect experiment. -Jonathan ------------------------------------------- Jonathan Fung... Reef Geek Dalhousie University Honours Marine Biology Aqua Creations Inc. Assistant Manager writer for Marine Fish Monthly ------------------------------------------- email: fung@is2.dal.ca ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!