Open AccessEnvironmental parameters and estivation of Rhyacodrilus (Tubificidae, Oligochaeta) in Lake Suwa, Japan
Author(s) -
Takada Kaori,
Kato Kenji,
Okino Tokio
Publication year - 1992
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1992.tb00043.x
Subject(s) - aestivation , oligochaeta (plant) , eutrophication , sediment , ecology , biology , environmental science , hydrology (agriculture) , geology , nutrient , paleontology , geotechnical engineering
We confirmed that Rhyacodrilus spp of Yasuda and Okino (1987) (Tubificidae, Oligochaeta) migrated entirely downward below 15 cm into the sediment from June to September m Lake Suwa, a shallow eutrophic lake in Japan In October, Rhyacodrilus spp began to return to the upper layer and immediately attained sexual maturity They tended to show reduced body weight and respiratory activity during summer The results indicate that an oligochaete of Rhyacodrilus spp estivated in the deeper layer during summer The estivation ostensibly occurred at 15°C and the species died off at 20°C, so it is evident that they must migrate from the surface to the deeper layer of sediment during summer in order to escape high temperature Furthermore, physiological experiment suggested that this behavior is accelerated by low oxygen concentration with high temperature