The potential costs to
copulation have been established relatively well.
The sea slug sheds 1/3 of the internal penis length after each
copulation.
Halffter (1997) proposed that when the sperm of a new
copulation are pulled inwards this pushes the sperm from previous
copulations deeper into the closed branch of the spermatheca.
The low number of
copulations with younger females may be related to the small amount of pheromone released by them, as was observed in studies carried out by Foster et al.
These included time of day, size of male and female, presence or absence of brooding eggs, number of chelae, position of mating crabs, shelter usage, duration of
copulation, and postcopulatory guarding.
Egg size was not related to number of
copulations (P < 0.
The patterns of sperm precedence, the increased frequency of starting and stopping
copulation with less actual time spent in copula of second males, suggests that the second males could not successfully copulate.
chaudoiri, including the same four phases of pre-mating struggle,
copulation, PCA and post-mating struggle.
Extramarital and pair
copulations in the cattle egret.
Pairing with a female confers at least two benefits for males at the spawning grounds:
copulation success and an "owner advantage" in fights.
The regression of the number of offspring sired against the number of
copulations was significant and revealed that 103.
During
copulation these males are known to sever their own genitals in an attempt to plug the female, thereby gaining paternity advantage by preventing other males from mating with her.
