1063-0740/04/3006- © 2004
Russian Journal of Marine Biology, Vol. 30, No. 6, 2004, pp. 402–413.
Original Russian Text Copyright © 2004 by Biologiya Morya, Kornienko, Korn.
Decapod crustaceans (Decapoda) are a numerous
and commercially important group of marine inverte-
brates. However, during the last 50 years almost no
studies on this group have been carried out in Russian
Far East waters. In particular, the studies on pelagic lar-
vae of crabs, their morphology and distribution in
plankton are conﬁned to the paper of Makarov , who
found zoea of ﬁve species of Brachyura in the shelf of
western Kamchatka. For Peter the Great Bay (Sea of
Japan) there is no available information concerning the
larvae of crabs.
The spider crab
(de Haan, 1850)
(family Majidae) is the only species of the genus
that occurs in Russian waters of the Sea of Japan .
It is distributed from Hong Kong to Peter the Great Bay
and western Sakhalin, along the eastern coast of the Jap-
anese Islands, around the Kuril Islands, and on the south-
ern coast of Sakhalin. It lives in depths of 2 to 324 m and
is common among coastal algae [1, 2].
The larvae of this species are brieﬂy described from
plankton samples collected in Sagami Bay  and lar-
vae reared in culture [6, 15]. In the literature there are
detailed descriptions of stages zoea I and megalopa,
obtained under laboratory conditions [8, 9] and incom-
plete descriptions of the stages of prezoea and zoea II
[6, 12, 15].
The target of this study was to study the entire life
in the laboratory culture, to pro-
vide detailed morphological description of all larval
stages and to determine the occurrence schedule of this
species in Vostok Bay, Sea of Japan.
MATERIALS AND METHODS
The studies were performed in August 2002 and
August 2003 at “Vostok” Biological Station of the
Institute of Marine Biology, Far East Division, Russian
Academy of Sciences (Vostok Bay, Sea of Japan). Egg-
bearing females of the spider crab
were collected at a depth of about 3 m and individually
maintained in aquariums until the hatching of larvae.
The crabs were fed pieces of mollusks every second
day; the water in the aquariums was changed every day.
The animals were monitored continually in order not to
miss the moment when the prezoea larvae appeared.
After hatching from the egg envelops, some larvae
were collected from the bottom of the aquarium with a
pipette and the stage of prezoea was ﬁxed. Then
(approximately 30 min later) the larvae that rose from
the bottom to the water’s surface were concentrated at
the edge of aquarium using a point light source. Some
larvae were ﬁxed (zoea I), while the others were trans-
ferred for further cultivation into 1-l vessels with ﬁl-
tered and UV-sterilized seawater. The temperature in
the aquarium chamber was maintained within
C. The density of the larvae equaled about 100
specimens/liter. The larvae were fed newly hatched
Morphological Features of the Larvae of Spider Crab
from the Northwestern Sea of Japan
E. S. Kornienko and O. M. Korn
Institute of Marine Biology, Far East Division, Russian Academy of Sciences,
Vladivostok, 690041 Russia
Received February 17, 2004
—The entire cycle of larval development of the spider crab
(de Haan, 1850)
(Decapoda: Majidae), widespread in Peter the Great Bay (Sea of Japan) is studied under the laboratory condi-
tions. The development cycle of this species comprises prezoea, zoea I, zoea II, and megalopa. At a temperature
C larval development took from 11 to 15 days. Zoea II is described in detail for the ﬁrst time. Many
morphological characters are found distinguishing zoea and megalopa of
in Russian waters from
the larvae of this species in Japanese and Korean waters. Some characters of larvae are similar in
and the related species of the genus
The larvae of
occur in the plankton of Vostok Bay
from late June to late October with a density up to 5 ind/m
at a surface water temperature of 13–21
are easily distinguished from the other brachyuran larvae of this region by the absence of lateral spines on the
crabs, prezoea, zoea, megalopa, larval development,
, Decapoda, Majidae.