ABSTRACT
Ingrid Ahnesjö1*, Elisabet Forsgren2 and Charlotta Kvarnemo3
Fishes show a fascinating diversity in mating systems and reproductive behaviours. Furthermore, various traits that seem to have evolved under sexual selection, like elongated fins, gaudy coloration, courtship, sounds and parental care behaviours, are widespread. In the environment that fishes live in, numerous factors may cause variation in sexual selection processes, including nest site abundance, temperature, predation risk and visibility. In the last two to three decades, fish have proven to be very good models for the study of sexual selection, and much of what we
know today, both empirically and theoretically, stems from such studies (Forsgren et al., 2002; Andersson and Simmons, 2006; Clutton-Brock 2007). One of the major advantages of studying fish in this respect is that they are often amenable to aquarium experiments. This allows us to manipulate the factors under study and to make stronger inferences regarding the causal chain of events. In addition, we also have much to learn by studying fishes in their natural environment.
