Hypoxia tolerance of three native and three alien species of bitterling inhabiting Lake Kasumigaura,Japan |
| |
Authors: | Takahiro Morosawa |
| |
Institution: | (1) Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba Ibaraki, 305-8572, Japan |
| |
Abstract: | Differences in hypoxia tolerance among three native and three alien bitterling species were examined by means of field surveys
and aquarium experiments. I caught fish in minnow traps and measured environmental factors such as dissolved oxygen and current
velocity once a month between June and November 2006 at 30 points around Lake Kasumigaura, Japan. In addition, aquarium experiments
were carried out to compare aquatic surface respiration thresholds among the bitterling species. Much more individuals of
an alien species, Rhodeus ocellatus ocellatus, was caught at the least oxygen range than expected in the field, and showed the highest hypoxia tolerance in the laboratory
experiments. Another alien bitterling, Acheilognathus rhombeus, also showed higher hypoxia tolerance than the three native bitterling species. Lake Kasumigaura is well known for eutrophication
and water masses with low dissolved oxygen have often been observed there. Differences in hypoxia tolerance among bitterling
species might have affected bitterling assemblage structure in Lake Kasumigaura, which is currently characterized by the dominance
of R. o. ocellatus. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|