Dictionary of Ichthyology  

egg dummy = an egg-like spot, e.g. on the anal fin of mouthbrooding Cichlidae. The male cichlid displays these spots to a female who sucks at the spots assuming them to be real eggs; the male releases sperm that fertilise the eggs in the mouth of the female. Also called egg spots or false eggs.

Paratilapia longirostris (= Haplochromis longirostris) from Boulenger's "The Fishes of the Nile". Photograph by Brian W. Coad.

Canadian Museum of Nature
www.briancoad.com