Posted by Shari Horowitz in Tropical Fish Hobbyist Blog on October 13, 2011 at 10:18 am
By David E. Boruchowitz
Cichlids demonstrate extremely sophisticated reproductive strategies. One of the least common involves cooperative breeding in groups or colonies. Lake Tanganyikan Neolamprologus pulcher breed en masse, with the entire colony rising as one to fend off predators, and with non breeding individuals participating in the care and protection of the offspring.
Aquarists have long known about this behavior, which is more obvious in the wild, where hundreds of fish are involved, but which translates in captivity into breeding groups that avoid the typical predation on the fry by non parental adults in the same tank.
A new study reveals that about 10 percent of the fry produced in these colonies are sired by subordinate males, and that those males are more diligent in protecting the young.
This is reminiscent of the situation in several Xiphophorus swordtails, where smaller, inconspicuous males rely on sneaking rather than courtship to father a small percentage of fry. In both cases subordinate males father a small but significant number of offspring, though in the case of the swordtails it is a matter of genetic castes among the males, not just one of dominance.
Tags: cichlids, colonies, cooperative breeding, courtship, dominance, fry, inconspicuous males, Lake Tanganyika, Neolamprologus pulcher, non parental adults, paternity, predation, reproductive strategies, sneaking, subordinate males, swordtails, Xiphophorus