The Peacock Goby is a small fish from Papua New Guinea. It has colours to rival some of the brightest killifish, purple, red, blue and yellow, and is easy to keep and breed. Sexing is easy in fish which are 1" or larger, the male having a distinctly rounded head, longer finnage, and an absence of black markings on his fins, whereas the female has a tapered head, a plumper stomach and usually, a black edge to her anal fin. As the female comes into breeding condition her bulging stomach area becomes brighter yellow, and is displayed to the male by bending her head and tail away from him, in a manner similar to that employed by female "Kribensis".
These fish do not appear to be too fussy about water conditions, breeding in soft, slightly acid, to hard and alkaline water. They do however show a marked preference for live foods, ignoring flake or pellets. Some frozen foods are taken, notably, bloodworms.
For breeding, I place a pair in an 18"x10"x10" aquarium, pH 7.2, temperature 78 F. The substrate consists of about 2" of fine gravel over an undergravel filter.
Cover is supplied by small flowerpots and pieces of slate, with a few clumps of Java Moss to complete the set-up.
The male is about 1.5", the female slightly smaller. To condition the fish they are fed live foods, mainly bloodworms. Within a couple of days of their introduction the male will establish which is his flowerpot, and rushes out to display to the female if she happens to get close.
When ready to spawn, the female responds to the males display with one of her own. The male now tries to entice her into his 'cave' by fluttering and spreading his fins in front of her, and then darting into the flowerpot. Eventually she follows him in. The following day the female is out and about again, noticeably thinner and duller. The male will not be lured out even when live food is offered. At this point I remove the female.
Eight to ten days later, the first free swimming fry are evident, but still no male! He will appear only after all the eggs have hatched, and pays little or no attention to the fifty or so fry which are now swimming about the tank, but will take any bloodworms that are offered. To prevent temptation I now take the male out. The fry grow quickly on a diet of brine shrimp nauplii, and newly hatched mosquito larvae, reaching about 0.5" after 4 to 5 weeks.