Mate Selection Is Based on Looks

A new Queen's University study found, for the first time, that there are differences in the way males and females of the same species of vertebrate see things, and that they use their sight to choose their mates.

PhD candidate Shai Sabbah, a Vanier Scholar, and leader of the team, along with his colleagues, studied male and female cichlid fish, and concluded that not only do they see things differently, they also detect light in different ways.

Cichlids are small, very colorful fish found in many lakes around the world and in aquariums in North America.

The females are dull in color, while males are the complete opposite and often show colorful body markings.

The research team found out that the fish have five photoreceptor cones in their eyes to help them detect colors, which is more than all other vertebrates (humans have only three).

This gives them a chance of making a very good difference between colors and correctly choose their mate.

Mr. Sabbah explained that “it is difficult to say what color attracts the female the most, but we know that if we manipulate the color of the fish by changing the light in the environment, the female fish will fail to choose a male of her own species.”

He explains that in nature, human development and deforestation rise water muddiness, altering the visual environment of fish, and preventing them from making the correct choice in mates.

This can ultimately endanger the survival of the species, and since “these fish depend on color vision for their own survival, discovering differences in the highly dimensional visual systems of males and females is a significant finding,” added Mr. Sabbah.

Himself, along with other members in Craig Hawryshyn's laboratory are now analyzing the way that these differences in the visual abilities of male and female cichlids affect their behavior.

The results of the research were recently published in BMC Biology.