南樺太湖沼の豫察研究

Abstract

A limnological survey was carried on by the writer in the following lakes of South Sakhalin in the summer of 1934; Tibesani-taiko, Tibesani-syôko, Waai-ko and Horahune-ko on the coast of Aniwa-wan (Aniva Bay), and Tyatya-numa, Bakko-numa and Raitisi-ko on the west coast. The morpbometrical data of these lakes are given in tables 1 and 8, the temperature and pH in table 2, and the chemical properties of the lake water in table 7. Tibesani-taiko (table 3), Tibesani-syôko (table 4) and Horahune-ko (table 6) belong to eutrophic Corethra plumosus type with Einfeldia, and Waai-ko (table 5) to mesotrophic Einfeldia type. Raitisi-ko (table 10) is a brackish water lake and Macoma baltica, an eurythermal and euryhaline clam, is very common. There were collected many interesting animals which are new to Japanese fauna, e g. Kamaka kuthae, Piscicola geometra, Cristatella mucedo (statoblasts only), Limnochares holosericea, Thyas oblongata, Forelia ligulifera, Nereis alinensis OKUDA and Valvata pulchella saghalinensis MIYADI. All of them are recorded from Europe or Siberia, except the last two which are new to science.