Aquaporin-4 immunoreactivity in Müller and amacrine cells of marine teleost fish retina

► We studied the immunoreactivity of Aquaporin-4 (AQP4) in the teleost fish retina. ► AQP4 is expressed in cone photoreceptors, Müller cells and amacrine cells. ► AQP4 is expressed in a GABAergic subpopulation of amacrine cells (AQP4-ACs). ► AQP4 immunoreactivity was stronger in dark-adapted retinas. ► The cell size of AQP4-ACs increased with the dark-adapted condition.