用水晶体干重鉴定五趾跳鼠的种群年龄

THE AGE IDENTIFICATION OF POPULATION OF FIVE-TOET JERBOA WITH LENS

利用556只五趾跳鼠的水晶体干重作次数分配,将该鼠年龄划分成7个组进行观察:幼年组水晶体干重在55.00毫克以下,亚成年组55.01-77.50毫克(当年出生),成年Ⅰ组55.01-87.50毫克(经过一次冬眠并参加繁殖),成年Ⅱ组87.51-102.50毫克,成年重组102.51-117.50毫克,成年Ⅳ组117.51-130.00毫克,老年组130.01毫克以上。据1986和1987年的观察,结果表明五趾跳鼠年龄组成季节变化明显,年度之间没有显著变化。

The studies are based upon the samples of five-toet jerboa (Allactaga sibirica) collected from Huhohoat district from March to October 1986 and 1987. A total number of 556 specimes were collected, among which 324 were males and 232 females. With the lens weight of five-toet jerboa as the age criteria, 7 age groups were recognized. The standerds of these age groups were listed below: Group 1 Juvenile: The lens weight was less than 55.00 mg. Group 2 Subadult: The lens weight was 55.01-77.50 mg. Group 3 Adult (Ⅰ). The lens weight was 55.01-87.50mg. Group 4 Adult (Ⅱ). The lens weight was 87.51-102.50mg. Group 5 Adult (Ⅲ). The lens weight was 102.51-117.50mg. Group 6 Adult (Ⅳ). The lens weight was 117.51-130.00 mg. Group 7 Senil: The lens weight was more than 130.00 mg. The subadults were born from June to October this year. The adults ( Ⅰ ) were collected before June or the breeding was collected after June. This paper shows that body weight, body Iength and tail length are not suitable for the age indicators of five-toet jerboa. Five-toet jerboa is an animal in hibernal sleep, that is from October to March of next year. Before June the collected specimens all were born in the last year and two years ago. The greater part of five-toet jerboa breed one time in the year. In this year the born juveniles and subadults appeared in July, August and September. The specimens of the adult (Ⅰ-Ⅳ) and the older were collected in June, that were born in last year, the year before last year, two, three and four years ago respectivelly, so to the five-toet jerboa can live five years old, but the most of them only live two to four years.