1063-0740/05/3105- © 2005 Pleiades Publishing, Inc.
Russian Journal of Marine Biology, Vol. 31, No. 5, 2005, pp. 294–302.
Original Russian Text Copyright © 2005 by Biologiya Morya, Kashenko.
The Amur starﬁsh,
, is an Asian
low-boreal species widely distributed in the Sea of
Japan and Sea of Okhotsk that, during the last two
decades, has also penetrated into the coastal waters of
Australia (Tasmania). Both Russian and foreign scien-
tists have demonstrated great interest in studies on the
distribution, biology, and development of the Amur
starﬁsh [1, 3, 4, 6, 7–10, 14, 17, 18, 22, 24–26, 28, 36].
is a predator that eats a multitude of com-
mercial mollusks and some echinoderms, both in the
natural environment and in maricultural farms of Japan
and Australia, which provided particular stimuli for
extensive studies on this species [2, 23, 24, 27, 29, 30,
32–35]. The Amur starﬁsh successfully penetrates into
new habitats differing from each other in temperature
and salinity regime [14, 16, 22, 33]. A major role in the
dispersion of this species is played by larvae, which
develop in plankton for a long time [3, 4, 9, 15, 22, 28].
Depending on the depth of their habitats, the larvae
might be exposed to either small or sharp ﬂuctuations
in the temperature and salinity of seawater. Fertilization
and the embryonic development of
place close to the bottom; after oviposition, the eggs
sink to the substrate. At the stage of blastula, the larvae
stay closer to the surface, while at the stages of gastrula
and dipleurula, they can already swim in deeper water
layers. Prior to settlement, at the stages of bipinnaria
and brachiolaria, the larvae move down, closer to the
bottom. As is mentioned by Gabaev [3, 4], in Pos’eta
Bay the settlement of Amur starﬁsh happens mostly
often in the water layer of 3.5 to 6.5 m deep, but the
young occur down to 14 m deep.
The target of this study was to determine the ranges
of temperature and salinity at which the embryos and
can survive and successfully
develop in Vostok Bay, Sea of Japan.
MATERIALS AND METHODS
This project was conducted at
logical Station of the Institute of Marine Biology, Far
East Division, Russian Academy of Sciences (Vostok
Bay, Sea of Japan), from June to August 2000.
Adult prespawning starﬁsh
collected on June 9 from a depth of 3–4 m, at a water
temperature of 10–11
C and a salinity of 31.6‰ and
placed into a tank with running seawater at the same
values of the environmental factors. The animals that
spawned immediately were released back into the sea,
while the others (21 specimens), with rays 12–15 cm
long, were maintained in the tank for one week for
was stimulated by an
increase in the water temperature in the tank from 11 to
C. Females and males began spawning in 30 min
and 2 h 30 min after the heating of water up to 15
respectively. Released female and male gametes were
collected into separate glasses. For artiﬁcial fertiliza-
tion we chose developed eggs obtained from three
Responses of Embryos and Larvae of the Starfish
to Changes in Temperature and Salinity
S. D. Kashenko
Institute of Marine Biology, Far Eastern Division, Russian Academy of Sciences, Vladivostok 690041, Russia
Receivted June 15, 2004
—We studied the effects of different combinations of temperature (5, 10, 14, 17, 20, and 22
salinity (from 32 to 8‰) on the development of the starﬁsh
Lütken from Vostok Bay, Sea
of Japan. Embryonic development is the most vulnerable stage; it passes successfully at 10–17
C and the salin-
ity range of 32 to 26‰. Blastulae are the most tolerant of changing environmental factors. They survive and
develop at the temperatures of 5–17
C and in the salinity range of 32–18‰. Gastrulae and bipinnariae survive
under higher temperature values and salinity from 32 to 20‰. The tolerance for decreased salinity during the
process of fertilization and in the latest stage of development, the brachiolaria with the developing juvenile star-
ﬁsh, was conﬁned to the salinity range of 32–22‰, which agrees with the tolerance of adult starﬁsh
Thus, for normal development of the Amur starﬁsh in the early stages, some particular conditions
of temperature and salinity are required. This is, probably, due to adaptive capabilities of each developmental
stage and the peculiarities of the ecological conditions at particular depths.
, development, larvae, temperature, salinity, adaptations.