水生菌科(Saprolegniaceae)是一群常見的水生羽狀鞭毛菌類，其生活史包括：具有雙鞭毛游孢子的無性生殖和產生藏卵器及藏精器的有性生殖。通常棲息於淡水水域或潮濕的土壤中，主要行腐生生活，只有少數種類行寄生生活。共包含二十個屬，約一百四十種。從台灣地區採集的土壤和水樣，以餌釣法(baiting method)，利用亞麻種子和蛇皮做為餌物進行水生菌的分離，經玻璃環法(glass ring method)和1/4愛默遜培養基(1/4 Emerson's YpSs Agar)加以純培養，並依據Coker(1923)、Johnson(1956)、Sparrow(1960)、Scott(1960)、Seymour(1970)、Dick(1973)之分類檢索表及相關文獻(Forbes, 1934；Cutter, 1941；Howard et al., 1970；Volz et al., 1974；Chiou & Chang, 1975, 1976；Chien, 1980；Chowdhery & Rai, 1980； Paul, 1983) 加以鑑定。 鑑定結果共得七屬十九種。分別為綿黴屬(Achlya)八種：迪巴利綿黴(A. debaryana)、擬綿黴(A. dubia)、鞭毛綿黴(A. flagellata)、異絲綿黴(A. klebsiana)、歐利安綿黴(A. orion)、水稻綿腐病菌(A. prolifera)、彎曲綿黴(A. recurva)、次中心綿黴(A. subcentrica)；絲囊黴屬(Aphanomyces)二種：擬螺卷絲囊黴(A. helicoides)、星絲囊黴(A. stellatus)；囊解水黴屬(Brevilegnia)一種：次中心囊解水黴(B. subcentrica)；網囊黴屬(Dictyuchus)一種：不孕網囊黴(D. sterile)；細囊黴屬(Leptolegnia)一種：波浪細囊黴(L. undulatae)；水生菌屬(Saprolegnia)五種：異絲水生菌(S.diclina)、水黴(S. ferax)、岸生水生菌(S. litoralis)、地下水生菌(S. subterranea)、土生水生菌(S. terrestris)；破囊黴屬(Thraustotheca)一種：棍棒破囊黴(T. clavata)。其中，歐利安綿黴(Achlya orion)、岸生水生菌(Saprolegnia litoralis)和地下水生菌(S. subterranea)為台灣新紀錄種，次中心綿黴(Achlya subcentrica)和波浪細囊黴(Leptolegnia undulatae)為新種。

Saprolegniaceae is a common group of aquatic Chromista. Its life cycle is composed of asexual reproduction generating biflagellate zoospores and sexual reproduction producing oogonium and antheridium. In general, it inhabits the flesh water and wet soil. Most of species live as saprophytic and only few species live as parasitic. There are 20 genera and about 140 species in the Family Saprolegniaceae. Water molds are isolated from the soil and water samples collected in Taiwan by using hemp-seed and snake skin as bait, are purely cultivated through glass ring method and 1/4 Emerson's YpSs Agar medium ,and then are identified according to keys: Coker(1923)、Johnson(1956)、Sparrow(1960)、Scott(1960)、Seymour(1970)、Dick(1973) and relative references (Forbes, 1934; Cutter, 1941; Howard et al., 1970; Volz et al., 1974; Chiou & Chang, 1975, 1976; Chien, 1980; Chowdhery & Rai, 1980; Paul, 1983). Totally, seven genera and nineteen species are successfully examined and identified namely：eight species of Achlya：A. debaryana、A. dubia、A. flagellata、A.klebsiana、A.orion、A.prolifera、A. recurva、A. subcentrica；two species of Aphanomyces：A. helicoides、A. stellatus；one species of Brevilegntia：B. subcentrica；one species of Dictyuchus：D. sterile；one species of Leptolegnia：L. undulatae；five species of Saprolegnia：S. diclina、S. ferax、S. litoralis、S. subterranea、S. terrestris；one species of Thraustotheca：T. clavata. Among them, Achlya orion、Saprolegnia litoralis and S. subterranea are described as new records to Taiwan, and Achlya subcentrica and Leptolegnia undulatae are new species.