Fig. 2. Hemoglobin levels in juvenile daphnids (D. magna) following treatment with the crustacean terpenoid hormone methyl farnesoate (A) and three synthetic analogs (B-D). Hemoglobin levels were assessed colorimetrically after 48 h exposure to the terpenoids. Ten daphnids were exposed to each treatment. Values are means ± S.E.M. ^*Significant difference from the respective control (0 nmol l^-1; P<0.05, ANOVA, Dunnetts t-test).