The Effect of a Gravid Spot on Courtship Behavior

Annagrace Lewis, Harrison Muegge, Emily McAfee, Rachel Ritchie


Mating rituals in Poecilia reticulata can show how sexual selection works, and how both males and females decide on who they will mate with. Males have been shown to be attracted to sexually ready females that are both brightly colored and large. The use of a gravid spot in mating can aid in showing if males are more attracted to females that are ready to mate, or females that have already given birth or are about to give birth. We are testing the function of the gravid spot in courtship behavior, and if it increases the amount of rituals displayed. Our hypothesis is that a bright colored, larger fish model without a gravid spot will have a greater amount of rituals displayed because the gravid spot can be an indication of pregnancy. Our hypothesis was supported since the male displayed more courtship behaviors towards our control model.

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