Annual Reproductive Cycle of the Formosan Wood Mouse, Apodemus Semotus

臺灣森鼠之生殖周期

黃步敏(Bu-Miin Huang) ； 林良恭(Liang-Kong Lin) ； 歐保羅(Paul S. Alexander)

《Zoological Studies》 36卷1期 (1997/01) Pp. 17-25

摘要

本研究在探討臺灣森鼠各月份生殖之表現，按月於臺灣中部合歡山地區（北緯24度）海拔約2300公尺虛，以捕鼠器採集臺灣森鼠樣本。採樣期間自民國73年10月起至75年3月止。有效之臺灣森鼠樣本共267隻，雄性森鼠之生殖腺重量在4月-5月份及9月-10月份間達到最高峰。相反的，在6月-7月份及12月-2月份間生殖腺重量明顯下降，雌性森鼠的卵巢重量在4月及9月份亦達到最高峰，雌性森鼠的懷孕及泌乳現象在4月-5月份及8月-12月份間均被發現。23隻懷孕雌鼠之平均胎兒數為3.83±0.8隻（2-6隻），平均排卵率（4.24±0.22個）及平均胎兒數之差異顯現臺灣森鼠胎見出生前之死亡率為12.8%。其中包含7.5%著床前死亡率及5.3%著床後死亡率。雌性森鼠子宮內不會發現二組以上之胎痕。在年齡結構及幼鼠出現時間的分析上，要顯示出臺灣森鼠具有雙峰型之年生殖周期型態。在環境因子及天候的探討上，年溫度變化與臺灣森鼠雙峰型之年生殖周期具有較密切的關係。

關鍵字

臺灣森鼠 ； 生殖 ； 小老鼠 ； 生殖腺 ； 雙峰型

並列摘要

The annual reproductive pattern of Apodemus semotus was studied. A. semotus specimens were trapped at monthly intervals from October 1984 through March 1986 at about 2 300 m elevation in the Hohuanshan area 'of central Taiwan (24° latitude). Reproductive parameters of 267 mice were measured. Seasonal changes in weights of male gonads showed peaks in April-May and September-October, whereas gonadal weights were sharply reduced and there was histological evidence of regression in June-July and December-February. Ovarian monthly mean weights also showed 2 peaks in April and September. Pregnant or lactating females were found in April-May and AugustDecember. Breeding was more frequent in autumn than in spring. The mean litter size of 23 pregnant mice was 3.83 ± 0.88 (range 2-6). The difference between litter size and ovulation rate (4.24 ± 0.22) indicates that prenatal mortality was 12.8%, including 7.5% pre-implantation mortality and 5.3% post-implantation mortality. No more than 2 sets of placental scars were found in any individual. Analyses of age structure and the time of appearance of juveniles give further evidence of a bimodal annual reproductive pattern tor A. semotus.

並列關鍵字

Rodent ； Reproduction ； Bimodal ； Gonad ； Apodemus