在台灣的亞洲蜆（Corbicula fluminea）其生殖腺構造和性比

The Gonadal Structure and Sex Ratio of Asian Clam Corbicula fluminea in Taiwan

蜆屬（Corbicula）的蜆依照其棲息環境與生殖腺的構造，可分為三種類群（1）生活於淡水，雌雄同體；（2）生活於淡水，雌雄異體；（3）生活於半淡鹹水，雌雄異體。為了瞭解在台灣的亞洲蜆（Corbicula fluminea）的生殖生物學，本研究以石蠟連續切片觀察每個台灣蜆的性腺發育並決定其性別。樣本採集自基隆（33個）、七堵（10個）、石碇（20個）、三峽（9個）、新屋（33個）、后里（68個）、蘇澳（20個）及花蓮（30個），共223個樣本。結果發現10個雄性個體（三峽1個、新屋2個與后里7個），其餘的樣本皆為雌雄同體（95.52％），整體雄性的比例為4.48％。未發現雌性個體。在台灣的亞洲蜆棲息於淡水，雌雄同體居多，雌雄異體只觀察到雄性個體，沒發現雌性個體。

The genus Corbicula can be divided into three groups by the living environment and reproduction mode: (1) living in freshwater, hermaphroditism (2) living in freshwater, dioecism, and (3) living in brackish water, dioecism. To understand the reproduction mode of Corbicula fluminea in Taiwan, we use the paraffin series section to observe the gonadal development and identify the sex. A total of 223 samples from Keelung (n=33), Qidu (n=10), Shiding (n=20), Sanxia (n=9), Xinwu (n=33), Houli (n=68), Su'ao (n=20) and Hualien (n=30) were investigated. Only ten males (Sanxia (n=1), Xinwu (n=2) and Houli (n=7); sex ratio (4.48%) were confirmed, the rest of the samples were hermaphroditism (95.52%), with no findings of female in the present study. The Asian clam in Taiwan inhabit freshwater, the majority are hermaphrodites, and only males are observed in dioecism.