Peacock Gudgeon (Tateurndina ocellicauda)

Despite the common name, peacock gudgeons aren't true gobies at all — they're sleeper gobies, a related but distinct family, and one of the rarer setups in the fish world where males actually take over parental duty, claiming a cave and standing guard over the eggs solo once a female obliges. Both sexes carry genuine iridescent color too, an unusual bit of equal-opportunity flash in a hobby where males usually get all the color.

Care level: Easy · Temperament: Peaceful · Max size: ~1.75" · Min tank: 10 gal · Diet: Carnivore, small live/frozen foods