Abstract
We investigated the habitat of the endangered Japanese eight-barbel loach, Lefua
echigonia (Cypriniformes: Cobitidae). This fish inhabits a stream that adjoins a construction
site on the university farm. The aim of this study was to document their occurrence and
growth during and after construction. During construction, an accident occurred that led
to the death of all the Japanese eight-barbel loaches due to the drainage of the stream. The
results of the study confirm that there was no significant change in the population density
of several investigated sections of the stream, even at the site of the accident. Moreover,
the growth of the recaptured individuals was assessed using the mark-recapture method，
and the effect of the accident was considered to be small. Despite the deterioration of water
quality in the stream during construction, the fish were still expected to swim upstream
from the river into the stream, because the habitat structure and continuity of the stream
with the Misawa River were not lost. Therefore, it was possible for the stream to re-emerge
as a habitat for the re-establishment of the Japanese eight-barbel loach.
