奈良県吉野川での底生動物の現存量 I : 1965年2月
1966 年 16 巻 3 号 p. 113-119
詳細
1966 年 16 巻 3 号 p. 113-119
In February of 1965,the benthic communities were investigated by the quadrat (50×50cm) sampling method at five stations along the main course of the River Yoshino-gawa, with the following results : 1. The aquatic insect larvae amounted to more than 98 per cent in number as well as in standing crop of all the benthic animals. More than 98 per cent of the aquatic insects consisted of the members of the next four orders ; Ephemeroptera, Plecoptera, Trichoptera and Diptera. 2. At the station of Ikada-ba, a species of torrential caddis-worms, Uenoa tokunagai, was very abundant at both the "Hayase"-rapid and"Hirase"-rapid. But, the net-spinning caddis-worms were rather few. These two characters gave several different aspects to the benthic community of this station. 3. At the other four stations, the standing crops of"Hayase"-rapids were more than those of"Hirase"-rapids, and the standing crops of the rapids were more than those of pools. In other aspects, the benthic communities of these four stations showed to some extent common characteristics, different from those at the station of Ikada-ba.
