关键词: 褐家鼠, 年龄, 繁殖

Abstract:

Objective To clarify age structure and fecundity of Rattus norvegicus population in Zhanjiang city, providing theoretical basis for early warning and formulating scientific prevention and control measures of rodent pests. Methods Rattus norvegicus were captured by cage traps from 2008 to 2011. Body weight, carcass weight, body length and tail length of test rats were measured. Reproductive organs were anatomized and developmental status was observed. Age groups were divided according to the frequency distribution characteristics of body weight and the developmental and reproductive status. Results Rattus norvegicus were divided into five age groups, juvenile group (Ⅰ,≤120 g), subadult group (Ⅱ,120-180 g), adult groupⅠ(Ⅲ, 180-240 g), adult group Ⅱ(Ⅳ, 240-390 g), and old group(Ⅴ, >390 g). Body weight and carcass weight between neighboring age class had extremely significant positive correlation. The overall fitting degree of age class based on body weight and carcass weight was high and the frequency dissimilarity rate was only 4.54%. The pregnant rate of the females kept increasing in all age classes and reached peak at age class Ⅳ. The average fetus and reproductive index kept increasing in all age classes. The size of testes kept increasing with age and the descending rate increased from 15.79% to 100%. Conclusion It was feasible to identify age classes by body weight. The population fecundity of R. norvegicus in Zhanjiang city kept growing in all age classes. The breeding population was mainly the adults and the old individuals.

Key words: Rattus norvegicus, Age, Reproduction