The male then guards the nest against predators. During this period, the male must survive on a limited supply of food, as he is not able to leave the immediate vicinity to hunt. The eggs rapidly develop into embryos, but these remain attached to the side of the nest until the age of about three to four weeks. After this time, they continue to cluster around and hide behind the male, until they are large enough to fend for themselves. This degree of parental care is very unusual among fishes.