Rio Mãe Luzia is a river flowing through the southern region of Santa Catarina, Brazil, situated within the broader Rio Araranguá basin. The river drains a landscape typical of southern Brazil's coastal zone, with its waters eventually contributing to the larger Araranguá drainage system. The area around Forquilha and Treviso is particularly notable along this river, representing the kind of subtropical freshwater environment that supports a diverse community of native fish species. The river has gained scientific recognition as a type locality for several endemic and newly described fish species, underscoring its ecological significance within the region.