More than a Mouthful
from the book, "Petrified Lightning"

Book: 
Petrified Lightning

More than a Mouthful

Of the many ways that animal species protect their young, the mouthbreeder has the most foolproof system. As its common name suggests, the female fish of the genus Haplochromis incubates the eggs in her mouth. Even more unusual, she takes the eggs in her mouth the moment they are laid, before they have been fertilized by the male.

This would be a monumental oversight except that the male is equipped to deal with it. The anal fin of the male mouthbreeder is sprinkled with bright orange spots that look very much like the mouthful of eggs the female is carrying. The sight of these spots inspires her to try to add them to her brood. As she opens her mouth she takes in milt (sperm—laden fluid) that the male releases into the water, and fertilization takes place.

The mouthbreeder refuses food during the two to four weeks that the brood is being incubated in her mouth. As the eggs grow, her lower jaw stretches and becomes deeper and her belly shrinks, so she appears to be all head. When tiny eyes can be seen on the eggs in her mouth, she is about to give birth. About 30 to 80 are expelled in a stream, and the mother swims near them for a week or more. Whenever danger threatens they jostle each other in a frantic attempt to swim back to the safety of their mother's mouth. If they should be snapped up by any other adult mouthbreeder they will be eaten.

The mouthbreeder is one of the family of cichlids, many of which are popular tropical fish for the aquarium. Fanciers who wish to witness the incubation of eggs in a fish's mouth and watch the fry seek refuge in their mother's jaws will enjoy the mouthbreeder. The experience will be worth the trouble of placing aggressive fish in a separate tank or removing a fish with a brood from the threat of hungrier fish.