DISSERTATION RESEARCH: Testing the role of red carotenoid coloration in copepod mate choice

Auburn University, Auburn AL

Investigators

Abstract

Red colors are among the most widespread forms of animal signals. On one hand, the red coloration may be assessed by potential partners during mate-choice, where individuals with the brightest red color are more likely to be chosen as a mate. Evidence supports this idea in animals such as birds and fish. On the other hand, some research has found that red color may have a physiological function, for example, acting as a sunscreen that offers protection from potentially damaging solar radiation. This project uses copepods, tiny shrimp-like animals with bright red colors, to test whether to examine if red copepod color is (1) a signal of mate quality, (2) a sunscreen, or (3) both a signal of quality and a sunscreen. The results of this research will advance the basic understanding of animal coloration in group of animals that has not been well studied. In addition, the researchers will use this study system to bring science training to Alabama children in fourth through sixth grade. Working through a well-structured program--Getting Under The Surface (GUTS)--teams of parents and children from some of the most science-deficient school systems in the U.S. will be invited to half-day programs run by faculty. Two programs will be run involving the same student/parent teams. The bright red copepod system is ideal for capturing the attention of younger students while offering opportunities for training with microscopes and basic experimental design. Red carotenoid coloration is a widespread form of ornamentation in animals and extensive empirical data show that red coloration is an honest signal of individual quality and performance. However, the most popular vertebrate systems that clearly demonstrate selection for red carotenoid coloration via mate choice are not suitable for the physiological experiments needed to advance the field. The project focuses on physiological constraints on the production of red carotenoids in animals, using Tigriopus copepods as a model. The researchers use diet manipulations to vary carotenoid coloration and to test whether red colors in copepods are used as a visual signal in male and female mate choice, or whether red coloration acts as a protectant against UV radiation. This behavioral research will create a critical context for interpreting physiological research on carotenoid color production and enable better of understanding red coloration in copepods in particular and animals in general.