AI Article Synopsis
- Male three-spined sticklebacks were either castrated or underwent sham surgery and kept under long daylight conditions for a month.
- Sham-operated fish showed signs of breeding readiness, while castrated fish did not.
- The study suggests that longer light periods enhance secretory activity in the gonadal-pituitary axis of male sticklebacks, indicating a physiological positive feedback mechanism.
Article Abstract
Male three-spined sticklebacks caught in winter were castrated or sham-operated and subsequently kept under long photoperiod at about 20 degrees for a month. With this treatment the sham-operated fish attained breeding condition. The gonadotropic cells of the sham-operated fish contained significantly more dilated endoplasmic reticulum and fewer granules than those of the castrated fish, indicating a higher secretory activity of the gonadotrops in the sham-operated fish. These findings suggest the existence of a physiological positive feedback within the gonadal-pituitary axis of the male stickleback when stimulated into its breeding condition by long photoperiod.
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| http://dx.doi.org/10.1016/0016-6480(89)90027-0 | DOI Listing |
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