Life history of Rhyacophila lezeyi (Trichoptera: Rhyacophilidae) in the Shibukuro Stream, a tributary of the Tamagawa River receiving highly acidic and high temperature hot-spring inputs in northern Honshu, Japan.

AOYA Kokichi, TANIDA Kazumi

doi:10.3739/rikusui.84.19

Bibliographic Information

Other Title

高温強酸性温泉水の流入する渋黒川（秋田県玉川支流）におけるレゼイナガレトビケラRhyacophila lezeyi（トビケラ目,ナガレトビケラ科）の生活史
高温強酸性温泉水の流入する渋黒川(秋田県玉川支流)におけるレゼイナガレトビケラRhyacophila lezeyi(トビケラ目,ナガレトビケラ科)の生活史
コウオンキョウサンセイオンセンスイノリュウニュウスルシブクロカワ(アキタケンタマガワシリュウ)ニオケルレゼイナガレトビケラ Rhyacophila lezeyi(トビケラモク,ナガレトビケラカ)ノセイカツシ

Search this article

Abstract

The life history of Rhyacophila lezeyi was investigated at a highly acidic mountain stream, the Shibukuro Stream (pH 2.98 on average) of the Tamagawa River, the Omonogawa River System, Akita Prefecture, northern Honshu, from May 2017 to November 2019. Automatic recording of stream temperature was conducted at one hour or two hours intervals from October 2017 to November 2019. The stream receives inputs from a hot spring, and the stream temperature was distinctly higher than that of the neighboring mountain streams lacking hot spring water inputs.The difference in water temperature was more pronounced in the winter. The larvae of Rhyacophila lezeyi mostly pupated and emerged from late May to early July, but pupation continued until mid-October in the present study. Five instars were present almost continuously from April to November, and no clear temporal delineation of instars was observed. It was presumed that this species has a less synchronous (asynchronous) univoltine life cycle in the stream. We estimated the developmental zero temperature of rearing pupae (DZ-P) as 6.8 ℃ from the minimum deviations of effective degree days calculated by tentative DZ. The stream temperature probably exceeded the DZ of larvae (supposed to be close to DZ-P) during some periods of winter due to the input of hot spring water, which facilitated larval growth and development, even in winter. This peculiar stream thermal regime seems to be a major factor resulting in the less synchronous life-cycle observed for R. lezeyi in the stream.

Journal

Japanese Journal of Limnology (Rikusuigaku Zasshi)

Japanese Journal of Limnology (Rikusuigaku Zasshi) 84 (1), 19-35, 2023-02-25

The Japanese Society of Limnology

Keywords

Details 詳細情報について

Export

Life history of <i>Rhyacophila lezeyi</i> (Trichoptera: Rhyacophilidae) in the Shibukuro Stream, a tributary of the Tamagawa River receiving highly acidic and high temperature hot-spring inputs in northern Honshu, Japan.