ISSN 1063-0740, Russian Journal of Marine Biology, 2008, Vol. 34, No. 3, pp. 191–194. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.S. Sokolovsky, T.G. Sokolovskaya, 2008, published in Biologiya Morya.
The sea poachers (Agonidae) are poorly studied
ﬁshes. The last revision of this family showed that the
group includes 47 species, 43 of these are recorded for
the northern part of the Paciﬁc Ocean . Eighteen
species of sea poachers are documented for the Sea of
Japan , and 16 species are recorded for Peter the
Great Bay .
The majority of the sea poacher species are benthic
ﬁsh inhabiting the shelf zone from shallows to 100–150 m
deep; they are small- (7–20 cm) or middle-sized (to
50 cm). These ﬁsh are limited in number, they do not
gather in schools and occur usually as single speci-
mens. The sea poachers have no commercial value, but
they are of scientiﬁc interest for estimating the biologi-
cal diversity of an area. Data on biology, habitation,
ecology of spawning, and ontogenesis of this ﬁsh group
are sparse and have been included in works on system-
atics and distribution [1, 2, 6, 7, 12].
There is no information on the early ontogenesis of
the sea poacher in the Russian literature. Very limited
data on the early ontogenesis of the sea poachers inhab-
iting the northern Paciﬁc is also available in the interna-
tional literature. We found some data on the larval
development of eight species of Agonidae from the
north-eastern Paciﬁc in a paper by American scientists
. The Japanese ichthyologists Maeda and Amaoka
 published their results on larvae collected on the
coasts of Hokkaido Island. However, the descriptions in
these works mostly referred to generic names, such as
sp. and others.
Only one original drawing is given for the identiﬁed
species. The most complete publication on the early
ontogenesis of the ﬁshes of Japan  includes data on
development and original drawings of seven Agonidae
species, except for
the available literature data do not sufﬁciently present
all the peculiarities and the sequence of larval develop-
ment for many sea poacher species. The early ontogen-
esis of the Sakhalin sea poacher has not been described
in any of publications mentioned.
The availability of many-sized larvae, fry, and
young specimens of the Sakhalin sea poacher in ichthy-
oplanktonic samplings from Peter the Great Bay
allowed us to describe the early ontogenesis of this spe-
cies in more detail.
MATERIAL AND METHODS
The materials used in the study were collected in
April–October 1992–2007 in different sites of Peter the
Great Bay: south-western (Sivuchaya Bay, Possjet
Bay), north-eastern (Vostok Bay), and Amurskii Bay
(see table). Larvae, fry, and young specimens of the sea
poacher were caught by ﬁsh larva nets (IKS-80 and
BONGO), fry seine, and planktonic ﬁne-meshed hand
net. The planktonic hand net and fry seine were used
from the water edge line to a 1.5–2.0 m depth, and ﬁsh
larval nets were applied at a depth of 5–100 m.
Thirty-two specimens of the Sakhalin sea poacher
were thoroughly studied, including 16 larvae, 10 fry,
and 6 young specimens from the smallest that were
8 mm in size to completely formed young specimens
39–50 mm in length, with all the traits characteristic of
adult ﬁsh. As a result, we selected a series of the devel-
oping larvae and fry of the species. Larvae, fry and
young specimens were identiﬁed by morphological and
counting characteristics, as well as by peculiarities of
pigmentation by the method of series selection, from
bigger to smaller specimens.
Early Ontogenesis of the Sea Poacher
(Osteichthyes: Agonidae) from Peter the Great Bay, Sea of Japan
A. S. Sokolovsky and T. G. Sokolovskaya
A.V. Zhirmunsky Institute of Marine Biology, Far East Division, Russian Academy of Sciences, Vladivostok, 690041 Russia
Accepted November 13, 2007
—The description of developing larvae and fry of
is given for the ﬁrst time.
larvae and fry pass through a planktonic stage. In the course of growth and development, they
undergo the following morphological changes: the height of the head and the body decreases, the eyes become
shifted to the upper head proﬁle, the bases of the pectoral ﬁns become shifted to the lower region of the body;
the location of spikes and pigmentation change.
: Agonidae, sea poachers, Sakhalin poacher, morphological features, larvae, fry, pigmentation.