Vol. 47 No. 2, 2008

Sperm Storage, Delayed Ovulation, and Menstruation of the Female Rickett,s Big-Footed Bat (Myotis ricketti)

Zhe Wang1,2, Bing Liang1, Paul A. Racey3, Yan-Ling Wang1, and Shu-Yi Zhang4,*

¹Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
²Graduate University of Chinese Academy of Sciences, Beijing 100049, China
³School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
⁴School of Life Science, East China Normal University, Shanghai 200062, China

Zhe Wang, Bing Liang, Paul A. Racey, Yan-Ling Wang, and Shu-Yi Zhang (2008) We studied the reproductive cycle of female Myotis ricketti, a piscivorous bat widely distributed throughout Asia.  Copulation occurred from Oct. to Apr., sperm was stored by females, and ovulation was delayed until arousal from hibernation (in May and June).  Menstruation was observed during the preovulatory period; this is the 1st report of this phenomenon in the Vespertilionidae.  The serum concentration of estradiol (E₂) dramatically increased at menstruation.  Concentrations of progesterone (P₄) in non-pregnant bats did not significantly change.  Experiments to explore the effect of hormones on sperm storage and delayed ovulation showed that females continued to store spermatozoa 1 wk after an ovariectomy; all oocytes were in meiosis I in Nov.; and the single graafian follicle developed by the ovary could not be induced to ovulate by 10 IU human chorionic gonadotropin in Dec.

Key words: Histological section, Ovariectomy, Estradiol, Progesterone.

*Correspondence: Tel: 86-21-62235786.  Fax: 86-21-62235786.  E-mail:syzhang@bio.ecnu.edu.cn