著者

木崎原 祥文

出版者

一般社団法人 日本生物教育学会

雑誌

生物教育 (ISSN:0287119X)

巻号頁・発行日

vol.53, no.1, pp.36-40, 2012-08-31

参考文献数

11

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<p>The apple snail(Pomacea canaliculata) is a fresh water shellfish and was introduced by species, imported for food, from Latin America. It can be gathered from the paddy fields around Asakura High School, in Asakura-city, from July to September. In this experiment, a set of male and female apple snails are prepared for a group of two students. Students can identify a male and a female by the shape of the operculum and the shell mouth. One student dissects a male apple snail and the other a female one using the dissection scissors. When their shells are cracked, the penial sheath covering a penis for males and the red albumen gland for females can be distinctively observed respectively. For a male, the testis is located inside the black liver rolling like a spiral. By observing the prepared slide of the tissue of the testis with the light microscope, innumerable live sperms moving actively can be clearly observed. The apple snail has many merits for the observation material of sperms at the high school level.The merits are as follows;・500 to 1,000 apple snails can be gathered easily in paddy fields every year.・No student feels a resistance to gathering and dissecting the apple snail because it is regarded as one of the harmful beings to rice cultivation.・We can refer to the bad influence on the ecosystem by the alien speices and the spread of the parasite, Angiostrongylus cantonensis, by way of human's activity.</p>