Paternity and Mating Behaviors in the Sailfin Molly

Student: Jenell Betts ’20
Research Mentor: Shala Hankison (OWU Department of Zoology)

Patterns of courtship displays and mating preferences may be important in understanding how variation within and between species arises. Sailfin mollies (Poecilia latipinna) are an interesting species of fish because females will often mate with multiple males and there may be multiple fathers within one brood. In this mating system females may choose the highest quality males to increase her odds of having many healthy offspring. Our objective was to determine whether courtship behavior consistently correlated with the proportion of offspring fathered. Pairing two males with a receptive female, we recorded courtship and competitive behaviors. When the female gives birth, we will collect DNA samples from all offspring, from the female, and from both potential fathers. Then, we will amplify eight different microsatellite loci on the DNA to determine paternity. We plan to calculate the proportion of offspring fathered by each male to determine whether the number or length of courtship displays correlates to the proportion of offspring sired. We predict that males who perform more or longer courtship displays will father more offspring. Overall, this study will help us better understand how mating strategies relate to actual reproductive success.

In the fish species sailfin molly, males perform courtship displays to attract females. Our objective was to determine if the length and/or number of displays performed is related to the number of babies that the male fathers. We first paired a female with two males and observed and recorded their courtship behavior. Once the females have babies, we will do paternity tests on each of them, and determine which of the two males fathered more offspring.