Adult zebrafish were purchased from a commercial fish supplier and acclimatized for at least two-weeks in 20 L tanks with flow-through freshwater at 22°C. A single dose of 15 mg/kg of 5α-cyprinol, 5β-cyprinol 27-sulfate, 5α-scymnol or 5β-scymnol-27 sulfate, dissolved in sali...