Study on Centrocestus armatus in Korea. II. Recovery rate, growth and development of worms in albino rats

Abstract
Some biological characteristics of Centrocestus armatus were studied using albino rats as its experimental host. The metacercariae were collected from Zacco platypus by artificial digestion method. Laboratory rats (Wistar) were fed each 100 or 200 metacercariae and sacrificed on 1, 2, 3, 4, 5, 6, 8, 14 and 28 days after infection to recover worms of various ages. The average recovery rate was 10.7% from 82 rats. The rate decreased rather slowly for the first 8 days but showed a steep decrease thereafter. Of the worms, 35.5% were recovered from the duodenum and 62.5% from the jejunum. At metacercarial stage, body length was 293 microns and body width 144 microns. At adult stage, the length and width reached 382 microns and 214 microns respectively at 14 days after infection. The testes and Mehlis' gland were recognized at metacercarial stage, whereas the ovarian analage appeared on the 1st day of infection, seminal vesicle and vitellaria on the 2nd day, and seminal receptacle and uterine eggs on the 3rd day. Until 8 days after infection the genital organs developed continuously and the number of uterine eggs increased. The above results show that albino rats are one of useful experimental hosts for C. armatus and the worms can develop to adults in 3 days after infection.