Male and female parental roles in the monogamous cichlid, Tilapia mariae, introduced in Florida

We documented male and female parental roles of a monogamous fish, the spot ted tilapia, Tilapia mariae, in channelized rivers in southern Florida, whe re this species dominated the fish fauna within 10 years of their introduct ion. Clearly differentiated parental roles existed between males and female s, with females performing nearly all tending of embryos and most tending o f free embryos. After young became free-swimming and left the nest, however , males took over primary tending of the school of young while the female p atrolled the perimeter of the school and performed nearly all chases direct ed at predators. Male and female T. marine also traded off vigilance and fe eding, and showed a high degree of intrapair coordination. Experimental rem oval of one or both parents had major effects on parental behavior and broo d survival and integrity. Solitary females took on a parental role intermed iate between that of the male and female of a pair. Untended broods were at tacked by predators and scattered into aquatic vegetation, and were not obs erved to reform. Under dense nesting conditions we observed adoption of bro ods, group rearing of free-swimming young and the presence of non-breeder ' satellites' sharing and defending a territory with breeders. This highly co mplex parental care may have allowed T. mariae to invade fish communities d ominated by uniparental centrarchids, as well as allowing them to use distu rbed habitats such as channelized rivers that are of poor quality for nesti ng and rearing offspring.