Table 1. F₀ groups.

The number of male and female fish used in each F₀ treatment arm. All the fish were of the same strain, with the groups born a month apart from one another. We aimed to have 20 fertile fish in three tanks within each treatment arm in order to be able to detect a breeding odds ratio of 0.4 with 75% power [25]. On average there were 20 fish (5.7 fish/L) in each tank for group 2 and 3. In group 1, fertility screening only allowed 12 fish (3.4 fish/L) to be allocated into each tank. Tank 3 in group 1 has 10 fish due to mortality prior to the intervention.

Arm	Sex	Group 1			Group 2			Group 3
		Tank 1	Tank 2	Tank 3	Tank 1	Tank 2	Tank 3	Tank 1	Tank 2	Tank 3
5 mg	M	6	6	4	10	11	10	9	10	11
	F	6	6	6	10	9	10	10	10	9
60 mg	M	7	6	6	9	10	11	10	11	10
	F	5	6	6	11	10	9	10	9	10