O'Brien G M, Curlewis J D, Martin L
Department of Physiology and Pharmacology, University of Queensland, Australia.
J Reprod Fertil. 1993 May;98(1):121-7. doi: 10.1530/jrf.0.0980121.
Little red flying foxes (Pteropus scapulatus) are seasonal breeders: they mate in late spring/early summer, and young are born the following autumn. In captivity, males housed outdoors in a normal breeding colony in natural daylight showed a single cycle of testis growth and regression each year. During reproductive quiescence, testicular volume was approximately 2 cm3; recrudescence began soon after the winter solstice; testicular volume was maximum at approximately 6.5 cm3 at the spring equinox; and regression was complete by the end of summer. To test whether photoperiod entrains or synchronizes the cycle, groups of males were housed indoors, without females, at constant temperature, and artificial lighting was timed to either mimic naturally changing daylength or provide alternating 3-month periods of short (11 h light:13 h dark) or long (16 h light:8 h dark) days (two groups, three months out of phase with each other). During 18 months, the applied photoperiod protocol had no effect on the frequency of testicular cycles (which remained at one per year), the time course of recrudescence and regression (as described above for normal outdoor control males), or the completeness of growth and regression stages. These results suggest that male P. scapulatus are not reproductively photoresponsive.
小红狐蝠（Pteropus scapulatus）是季节性繁殖者：它们在春末/夏初交配，幼崽在次年秋天出生。在圈养环境中，置于户外正常繁殖群体且处于自然光照下的雄性每年睾丸会经历一个生长和退化周期。在繁殖静止期，睾丸体积约为2立方厘米；冬至后不久开始复苏；春分时节睾丸体积最大，约为6.5立方厘米；到夏末退化完成。为了测试光周期是否会引发或同步这个周期，将雄性分组饲养在室内，没有雌性，保持恒温，人工照明设置为要么模拟自然变化的日照长度，要么提供交替的3个月短日照（11小时光照：13小时黑暗）或长日照（16小时光照：8小时黑暗）（两组，彼此相差三个月）。在18个月期间，所应用的光周期方案对睾丸周期频率（仍为每年一次）、复苏和退化的时间进程（如上述正常户外对照雄性那样）或生长和退化阶段的完整性均无影响。这些结果表明，雄性小红狐蝠对光周期不产生生殖反应。
