Dissertation Research: Visual Factors Affecting Mate Choice in Lake Malawi Cichlids

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

Title: Visual factors affecting mate choice in Lake Malawi cichlids PI: Francis Juanes Doctoral student: Rebecca Jordan The cichlid fishes of Lake Malawi are an excellent example of rapid species diversification over a relatively short period of evolutionary time. There are numerous theories to explain this diversity that are often linked to sexual selection through female choice. Given that males are brightly colored, females, presumably by using visual cues, choose among the males. In being selective of certain males, females drive the reproductive isolation that lead to species differences. Little, however, has been done to investigate the visual factors used by female Lake Malawi cichlids. In fact very little has been done to discern what type of visual system these fish have, which is particularly surprising given their reliance on visually guided behaviors. The primary objective of this work is to ask four main visual questions with a group of rock dwelling Lake Malawi cichlids (mbuna): (I.) what spectral abilities exist across several groups? (II.) what is the role of visual cues in among species mate choice? (III.) what is the role of ultraviolet radiation in mate choice and feeding, and (IV.) what variation in physical characteristics occur with attenuating light? A critical understanding of the visual factors affecting the Lake Malawi mbuna is a necessary step in understanding of the reproductive isolation see in these fish. This understanding can aid in explaining the extreme diversity seen in these mbuna, and comes at pivotal time because of the anthropogenic stressors that currently threaten the integrity of the East African cichlid fish.