Hong Kong Hillstream Goby

Rhinogobius duospilus is found in fast-flowing, clear, cool hillstream habitats of Hong Kong and the Pearl River drainage of southern China. Males in breeding condition develop striking orange-red cheek spots and fin markings, creating a brilliant display against their white and brown bodies. It requires well-oxygenated, cool water to thrive.

Water: 18–24 °C, pH 7.0–8.0, hard freshwater; high oxygen and moderate to strong flow. Tank: 60 L minimum; river-style setup with smooth gravel, pebbles, and flat stones. Feeding: Carnivorous; frozen bloodworm, brine shrimp, small shrimp, and sinking pellets. Behaviour: Males are territorial toward each other; best kept as a pair or in larger tanks. Compatibility: Cool-water community fish; compatible with hillstream loaches and other rheophilic species.