Four groups of male starlings were exposed to stimulatory photoperiods. Two groups had 14 hours of light per day, the other two groups, 12 hours. One of the two groups treated with each photoperiod was in a cage including both male and female starlings; the other group was in a cage including only m
Testicular metamorphosis and prolongation of spermatogenesis in starlings (Sturnus vulgaris) in the absence of daily photostimulation
โ Scribed by Rutledge, James T. ;Schwab, Robert G.
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 453 KB
- Volume
- 187
- Category
- Article
- ISSN
- 0022-104X
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โฆ Synopsis
Abstract
Male European starlings (Sturnus vulgaris) were held in constant darkness for 448 days. Testicular widths, measured in situ via unilateral laparotomy at two to four week intervals, revealed that testicular growth reached a size associated with spermatogenesis in an average of 101 days. The spermatogenic period persisted for an average of 296 days. Histological examination of testes from two birds after 280 days of treatment revealed mature sperm in the seminiferous tubules. Complete testicular involution did not occur. Current photoperiodic theory must be modified to explain testicular metamorphosis without daily photostimulation in an avian species known to be photoperiodic.
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