Oviposition Observations in Oncomelania formosana

Abstract

Several workers have reported on field and laboratory observations on the life history of Oncomelania species, intermediate hosts of Schistosoma japonicum. Laboratory (Vogel, 1948) and field (Hsu, 1950) studies were made on 0. hupensis. F. C. Li (1934) gave an account of the ecology, among other aspects, of this Chinese species. Reports on 0. quadrasi are by Abbott (1946) and McMullen (1947). In recent years considerable work has been done on this snail in Leyte, Philippines (World Health Organization Reports). Observations on the reproductive habits of 0. nosophora are reported by Sugiura (1933), Ritchie et al (1951), McMullen et al (1951), Otori et al (1954, 1956). Roth and Wagner (1960) give an account of the production of eggs in 0. nosophora and 0. formosana, and Wagner and Wong (Chi) (1956) dealt with egg-laying in 0. nosophora and 0. quadrasi. Ecological habits of 0. formosana are reported by S. Y. Li (1953). Laboratory findings on the reproduction and growth of 0. quadrasi and 0. nosophora are given by Chi and Wagner (1957), with some data on 0. formosana. There are very few reports on the reproductive activities of 0. formosana and the present paper gives a more complete study of its reproductive habits.