Commonly, sexual selection changes with the seasons and level of development of an organism. “Seasonal changes in pheromone-detection ability and olfaction sensitivity over the reproductive cycle have been observed in mammals, birds, and teleost, but such seasonal shifts in the visual system are less well-developed”
It has been hypothesized that three-spine sticklebacks, Gasterosteus aculeatus, are more sensitive to red during the summer than the winter, which could be linked to the desire to perceive the red breeding color of males. One of three-spined stickleback male’s prominent sexual characteristics is their breeding color, which are blue eyes and a red belly. Many previous studies have been performed to show that their red belly is a …show more content…
Both of these traits were suppressed by castration and stimulated by 11 KA, a hormone that is a non-aromatisable androgen. Levels of lws mRNA were higher in sexually mature than immature male and female sticklebacks. Additionally, long day photoperiods did not increase lws mRNA levels in castrated males, but the androgen treatment had a distinct stimulatory effect on both lws mRNA and ERG red light sensitivity in castrated males. Based on the ERG results of this experiment, short photoperiod males were less sensitive to red light than males that were stimulated to breed by long photoperiod. These results show that red light sensitivity of stickleback’s changes during the breeding period. As demonstrated in the experiment with the bitterling, changes in spectrum sensitivity may be due to the differences in the photic environment. In eutrophic environments, spectral signaling became less successful. However, based on the finding in this experiment, effects of castration and androgen treatments given to the sticklebacks show a relationship between reproductive physiology and sensitivity to male
It has been hypothesized that three-spine sticklebacks, Gasterosteus aculeatus, are more sensitive to red during the summer than the winter, which could be linked to the desire to perceive the red breeding color of males. One of three-spined stickleback male’s prominent sexual characteristics is their breeding color, which are blue eyes and a red belly. Many previous studies have been performed to show that their red belly is a …show more content…
Both of these traits were suppressed by castration and stimulated by 11 KA, a hormone that is a non-aromatisable androgen. Levels of lws mRNA were higher in sexually mature than immature male and female sticklebacks. Additionally, long day photoperiods did not increase lws mRNA levels in castrated males, but the androgen treatment had a distinct stimulatory effect on both lws mRNA and ERG red light sensitivity in castrated males. Based on the ERG results of this experiment, short photoperiod males were less sensitive to red light than males that were stimulated to breed by long photoperiod. These results show that red light sensitivity of stickleback’s changes during the breeding period. As demonstrated in the experiment with the bitterling, changes in spectrum sensitivity may be due to the differences in the photic environment. In eutrophic environments, spectral signaling became less successful. However, based on the finding in this experiment, effects of castration and androgen treatments given to the sticklebacks show a relationship between reproductive physiology and sensitivity to male