Empire gudgeon

The empire gudgeon is a hardy sleeper goby from the coastal streams, lagoons and estuaries of northern and eastern Australia and southern New Guinea. Females and juveniles are plain, but breeding males become spectacular, flushing with red, orange, yellow and blue and flaring their tall dorsal and anal fins in constant display. Keeping several fish, ideally with more than one male, triggers this colourful sparring; the species is territorial and mildly aggressive rather than a schooler, so provide caves, wood and broken lines of sight. It tolerates a wide hardness range and low brackish conditions in nature, though it lives well in hard freshwater. A carnivore, it prefers meaty foods, taking frozen bloodworm, brine shrimp, chopped prawn and small live foods; many refuse flake initially. Larvae require brackish or marine water to develop, making captive breeding challenging.