The Nile tilapia, the predominant farmed tilapia species worldwide, displays an ability to thrive in low salinity waters not otherwise used for culture of conventional freshwater fish. The ability of early life stages to osmoregulate relies initially on chloride cells which are located on the body surface of larvae. These specialised cells are responsible for the trans-epithelial transport of ions, this being achieved using the transport protein Na+-K+-ATPase. In this study FluoroNanogold™ was used in combination with a Na+/K+-ATPase antibody on yolk-sac larvae of Nile tilapia that had been incubated and reared in brackish water. Chloride cells were detected directly by confocal scanning laser microscopy and subsequently by transmission electron microscopy. Scanning electron microscopy confirmed the appearance of the structure of the chloride cells on the surface of larvae. Results demonstrate that this integrated approach - used here for the first time on whole-mount fish specimens – offers valuable insight into the cellular localisation of Na+/K+-ATPase and morphology of chloride cells.