四国主として徳島県陸水の生物学的研究III.
龍河洞の陸水動物相
1939 年 9 巻 1 号 p. 1-5
詳細
1939 年 9 巻 1 号 p. 1-5
1. Limnological studies were carried out in a limestone cave "Ryu-ga-do" near Koti, Sikoku, on August 2, 1936 and March 26, 1937.
2. The physical and chemical properties of the water are shown in table 1. The tempe-tuie varied from 13°to 19°C, and its annual difference would seem to be smaller than 10°C. It may be said to be steno-thermal as a habitat for animals. The water was alkaline.
3. Eleven species of animals were collected (table 2), but no troglo-biotic forms were found among them. Bythinella nipponiea MORI, a minute gastropod (fig. 2), and Asellus (Asellas) nipponensis NICHOLS were the representative species in this cave. The former was found living chiefly under stones in the stream running through the cave, though it was also collected in very small numbers in the pool within the cave and in the stream outside the cave. The latter isopod, which is widely distributed in Japan, inhabits the pool within the cave, crawling or swimming about the surface of the mud. The specimens of Asellus from this cave are small and feebler than those from other inland waters. This is probably due to the nature of its habitat which is completely dark and has a very poor food supply. Lightly colored Euplanaria gonoce-phala was also found in the cave.
