A behavioral study on the effect of mating experiences with the same partner on mating activities of males and females in medaka fish

概要

In the general introduction, I mentioned that no studies have revealed the brain molecular
mechanism underlying the alteration of male mating behaviors according to the mating experience
of naïve males in fish species. To approach this issue, I decided to establish the behavioral assay
to measure the effect of the mating experience on male mating activity using model animals in the
field of molecular genetics. Therefore, I used medaka fish (Oryzias latipes) in the present study.
There are many advantages to using medaka fish for studying mating behavior. First, medaka
mating behavior comprises several steps (approach, courtship display, wrapping, wrapping
rejection and spawning). In addition, a mutant strain, whose body color is different between sexes,
is available for mating tests, which allows for quantification of sex-specific behaviors under
laboratory conditions easily 14. Second, as the female reproductive cycle is 24 h, the same female
ready to spawn can be used for mating tests every morning 15. Therefore, I thought that medaka is
one of the most suitable animals to validate the male mating plastically change.
In this chapter, I established the behavioral system to compare the male mating activity
between naïve and sexually-experienced males in medaka. First, I examined how the mating
experiences could change mating activities using naïve and experienced males. Second, I validated
whether the mating experiences altered female mating receptivity, which is negatively correlated
with the latency to mate after the first male courtship. Third, I tested whether the familiarization
with the same females induced the behavioral change or not. ...