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
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 .