MALE SIZE AND FEMALE MATE CHOICE IN THE EASTERN MOSQUITOFISH (GAMBUSIA-HOLBROOKI, POECILIIDAE)

In the western mosquitofish (Gambusia affinis), earlier studies demonstrated that females direct more cooperative behavior toward large males. Female eastern mosquitofish (G. holbrooki), including virgin and male-deprived specimens, which were given the opportunity to visually discriminate between two potential mates, showed no sign of sexual receptivity, nor preference for male size. Furthermore, when test females were allowed to choose between conspecifics, males and females spent three times as much time near females than near males. These results indicate little propensity of females to mate, irrespective of their previous treatment. When several males were placed with a female, the largest was usually able to monopolize access to her. Females encouraged this process by following the dominant male more closely and were, thus, found to favor the larger, dominant individuals. The diversity in mating strategy suggested by this study is further evidence in favor of the separation of the western and eastern mosquitofish at the species level.