奈良県吉野川での底生動物の現存量 : III. 1965年8月

概要

論文の詳細を見る
In August 1965,the benthic communities at the four stations in the River Yoshino-gawa, were investigated by the quadrat (50×50cm) sampling method with the following results : 1. The aquatic insect larvae amounted to more than 99 per cent in number and 97 percent in standing crop of all the benthic animals. More than 95 per cent of the aquatic insects consisted of the members of the next four orders ; Ephemeroptera, Plecoptera, Trichoptera and Diptera. 2. Comparing with the results obtained in April and May in the same year, the standing crops of the benthos increased to some extent. And, the ratios of the standing crops of caddis-worms, especially those of the net-spinning type, increased at many stations. On the other hand, insects of the creeping type, mainly of ephemerid larvae, decreased. 3. The general trend that the standing crops were the largest at "Hayase" -rapids and the smallest at "Huchi" -pools, was observed to have recovered in August.
日本生態学会の論文
1966-12-01