Final answer:
Body size, aggression, and testes size vary between territorial, satellite, and fader males, with territorial males being larger and more aggressive with smaller testes, satellite males being less aggressive with larger testes, and feeder males being the least aggressive and smallest, but possibly also having larger testes for sperm competition.
Step-by-step explanation:
In species with complex mating systems, body size, aggression, and testes size can vary significantly between different male strategies such as territorial, satellite, and feeder males. Territorial males often exhibit larger body size and higher levels of aggression to defend their territories and attract mates. This is because larger body size can be advantageous in physical confrontations and can also be preferred by females looking for strong and healthy mates. Territorial males tend to have smaller testes since they rely more on keeping other males away from their females than on sperm competition.
Satellite males, on the other hand, do not have their own territory and often exhibit less aggression and smaller body sizes compared to territorial males. Because they do not maintain a territory, they often adopt alternative mating tactics, such as sneaking copulations. Satellite males typically have larger testes to maximize their chances of fertilization during these brief, opportunistic mating events due to higher sperm competition.
Feeder males, which may mimic females or have other stealth mating strategies, often show even less aggression and have smaller body sizes since these qualities help them avoid detection by territorial males. Their testes size may again be larger to compensate for their stealth approach to mating, emphasizing the sperm competition aspect