Murray Itzkowitz - US grants

In many species monogamy appears necessary for successful reproduction. In this regard many of the previous studies have emphasized the stability of the pair bond (e.g., one parent cannot rear the offspring alone). However, much anecdotal evidence exists illustrating that monogamous bonds do break with pair members often re-pairing with other mates. This proposed research looks more closely at the initiation of the monogamous pair bond and re- pairing during the courtship period (i.e., prior to the production of offspring). The monogamous fish, Cichlasoma cyanoguttatum, will be used as the experimental animal model. Considerable baseline information has been gathered revealing it to be ideal for this purpose. Questions considered are: What are the affects of the repairing process on future reproduction? Is the duration of the courtship period with the initial mate an important component to an individual's ability to secure and reproduce with a new mate? Will already paired individuals switch mates based on reproductive improvement? Finally, experiments are planned to explore preliminary observations that suggest that the development of the monogamous pair bond is influenced by the number of available mates and the presence of intruders. All of these areas of study will emphasize possible differences between males and females.

DESCRIPTION (adapted from applicant's abstract): Here the investigator proposes to test, experimentally, three basic hypotheses on parental role division that were derived from correlational studies on humans. First, parental role division is based on the relative abilities and needs of each parent. Thus, the PI predicts that a large part of parental behavior is not based on inherent gender differences nor does a parent always attempt to off-load its responsibility onto the mate (as assumed in most studies on animals). However, he does anticipate that parental role conflicts will develop when parental differences are reduced. This conflict is manifested when both parents attempt to perform the same activity. Second, it is hypothesized that the resolution of this conflict is based on gender differences, and there is preliminary evidence that females dominate near the offspring while males may dominate away from the offspring. Third, it is hypothesized that gender differences also exist in the stimulus each parent uses in changing, or switching, parental roles. Preliminary evidence suggests that males begin offspring care when the female is absent while females begin irrespective of whether or not the male is present. Similarly, the female is predicted to increase her activities away from the offspring when the male is absent. The studies use the monogamous convict cichlid fish, Cichiasoma nigrofasciatum, as the animal model because, unlike mammals and birds, it is easy to manipulate parental abilities.