Comparison of escape
behavior of wild and hatchery-reared juvenile Japanese flounder Paralichthys
olivaceus
T.
Miyazaki, T. Seika, I. Kinoshita, K. Tsukamoto-2004
Fisheries
Science, 70(1): 7-10
Abstract:
The escape behavior of wild and hatchery-reared
juvenile Japanese flounder Paralichthys olivaceus from a dummy
predator, gray goblinfish Minous monodactylus, was investigated under
artificial light in an experimental tank. When the dummy predator
approached, both the juveniles quickly emerged from the sand, escaping
primarily by swimming close to the bottom (benthic swimming) rather than off
the bottom (off-bottom swimming). It is suggested that juvenile flounders
might escape in this manner from a diurnal visual feeder in the daytime,
owing to the flounder being virtually undetectable visually when close to
the bottom. The average escape swimming speed of an individual of 9.3 total
length (TL)/s in wild fish and 9.8 TL/s in
hatchery-reared fish was similar to the maximum speed of many fish species.
Juvenile flounder escaped more quickly and had a higher swimming speed (v
cm/s), when their distance (d cm) to the dummy predator decreased (v =
-2.7d + 82.1,
r = -0.33;
anova, P < 0.02).
Department of Life Sciences, Faculty of Bioresources,
Mie University, Tsu, Mie 514-8507, Japan, Tel: 81-59-231-9533. Fax:
81-59-231-9523. Email: taeko@bio.mie-u.ac.jp