Behavior of two types of hatchery-raised 0-group red sea bream after release in Hiuchi-nada, Seto Inland Sea
T.
Yamada, S. Kaji, M. Watanabe, E. Hasegawa, T. Fukunaga-2004
Nippon
Suisan Gakkaishi, 70(2): 152-158
Abstract:
After
their release into natural waters at a small inlet in the Seto Inland Sea,
two groups of juvenile red sea bream, Pagrus major, reared under
either low- or high-intensity light were studied to clarify changes in
behavior and population size. Released fish showed two behaviors:
aggregation and solitary. The low-intensity light group showed predominance
over the high-intensity light group both in the number of solitary
individuals and the spatial distribution area in the small inlet.
Differences in these characters between the two rearing groups caused
differences in the number of individuals able to win territories in the
process of behavioral shift from aggregation to solitary type during 4-5
days after release.
(Hakatajima
Station, National Center for Stock Enhancement, Hakata, Ehime 794-2305,
Japan)