Studies on ecology of marine chironomids in southwestern Japan

西南日本において海産ユスリカの生態に関わる研究を行った。その結果，計20種が採集され，垂直分布では，潮間帯上部あるいは中部域のみに分布する種は少なかったが，下部域のみに分布する種は多かった。基質については岩石面や泥中のみに棲む種は少なかったのに対し，海藻類のみに棲む種は多かった。また，地理的分布では南西諸島や本土外洋沿岸域のみに分布する種は少なかった。一方，数種は，瀬戸内海沿岸と本土外洋沿岸域，本土外洋沿岸域と南西諸島，あるいは全地域に分布することが分かった。また，羽化時期については，Dicrotendipes enteromorphaeは夏季・秋季のみ，S. endocladiaeは周年出現し，他種は秋季・冬季のみあるいは冬季・春季のみに出現した。これらのことから，潮間帯には様々な生活様式を持つ多くの種のユスリカが棲息し，生態系において重要な役割を果たしていることが示唆された。

Ecological studies were conducted on marine chironomids in south-western Japan. A total of 20 species was collected. For vertical distribution, only a few species was distributed only at high or middle intertidal zone while many species were distributed only at low zone. For substrate preference, some species were collected only on rocks or in mud while many species were collected only in seaweeds. For geographical distribution, a few species was collected only in the southwestern islands or in the oceanic coast in the Japanese main islands. In contrast, some species were collected in the Seto Inland Sea and the oceanic coast in the main islands, in the oceanic coast in the main islands and the southwestern islands, or in all areas. For seasonal emergence, Dicrotendipes enteromorphae was collected only in summer and autumn, and Semiocladius endocladiae was collected in all seasons. Other species were collected only in autumn and winter, or only in winter and spring. These results suggest that many chironomid species with a variety of lifestyles dwell in intertidal zones and have some important roles in the ecosystems.