anchor: If the sheepshead minnow, Cyprindon variegatus, larval survival and growth test is begun with less-than-24-h old larvae, the mean dry weight of the surviving larvae in the control chambers at the end of the test must equal or exceed 0.60 mg, if the weights are determined immediately, or
positive: The mean dry weight of the control larvae that survived at the end of the experiment must be greater than or equal to 0.60 mg.
negative: The weights of the larvae are never determined before, during, or after the test.