Gemmell R T, Sernia C
Department of Anatomical Sciences, Physiology, and Pharmacology, University of Queensland, Brisbane, Australia.
J Exp Zool. 1995 Oct 15;273(3):242-6. doi: 10.1002/jez.1402730309.
In Queensland, possums (Trichosurus vulpecula) in the wild and in captivity first give birth during March and April and continue to give birth throughout the year until November. The possum has a gestation length of 17.5 days, gives birth to one young, and lactation continues for approximately 180 days. If the newborn possum is removed during the breeding season, the possum will ovulate approximately 9 days later and give birth approximately 26 days after removal of the pouch young (RPY). Repeated RPY may be used to determine the duration of the breeding season. In this study, the effect on the breeding season of a marked change in photoperiod From a short-day to a long-day was examined by comparing three groups of possums in different photoperiods for 13 months. One group of five female and two mail possums (group A) was housed in a natural photoperiod and a second group (B) was housed in a short-day photoperiod (10 h light: 14 h dark) throughout the study. The third group (C) was housed in a short-day photoperiod until each possum gave birth, the pouch young was removed, and the possum transferred to a long-day photoperiod room (14 h light: 10 h dark) for the remainder of the study. The possums held in a natural photoperiod, group A, gave birth to a total of 27 births in the one breeding season from March to October.(ABSTRACT TRUNCATED AT 250 WORDS)
在昆士兰，野生和圈养的负鼠（帚尾袋貂）首次产仔时间为3月和4月，并持续全年产仔直至11月。负鼠的妊娠期为17.5天，每胎产一仔，哺乳期约持续180天。如果在繁殖季节将新生负鼠取出，负鼠大约会在9天后排卵，并在取出育儿袋幼崽（RPY）后约26天产仔。重复取出育儿袋幼崽可用于确定繁殖季节的时长。在本研究中，通过比较三组处于不同光照周期的负鼠，为期13个月，研究了光照周期从短日照显著变为长日照对繁殖季节的影响。一组由五只雌性和两只雄性负鼠组成（A组），饲养在自然光照周期下；第二组（B组）在整个研究过程中饲养在短日照光照周期（10小时光照：14小时黑暗）下。第三组（C组）在短日照光照周期下饲养，直到每只负鼠产仔，取出育儿袋幼崽，然后在研究的剩余时间将负鼠转移到长日照光照周期的房间（14小时光照：10小时黑暗）。处于自然光照周期的A组负鼠在3月至10月的一个繁殖季节中共产仔27次。（摘要截断于250字）
