Comparisons of two types of teleostean pseudobranchs, silver moony (Monodactylus argenteus) and tilapia (Oreochromis mossambicus), with salinity-dependent morphology and ion transporter expression.

There are essentially four different morphological types of pseudobranchs in teleosts, including lamellae-free, lamellae semi-free, covered, and embedded types. In the euryhaline silver moony (Monodactylus argenteus), the pseudobranch belongs to the lamellae semi-free type, which is characterized by one row of filaments on the opercular membrane and fusion on the buccal edge. The pseudobranchial epithelium of the moony contains two types of Na(+), K(+)-ATPase (NKA)-rich cells: chloride cells (CCs) and pseudobranch-type cells (PSCs).