ISSN 1063-0740, Russian Journal of Marine Biology, 2008, Vol. 34, No. 2, pp. 94–100. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.P. Kasatkina, 2008, published in Biologiya Morya.
To date, 16 species of the genus
been described from the Sea of Japan. The ﬁndings of
four new species expand the species list of this genus.
found in coastal tropical
waters , according the modern classiﬁcation [1, 3, 6],
should be referred to as
et Nairi, 2002) comb. nov. In this paper we provide
descriptions and original drawings of four new species
and identiﬁcation keys for all 32 species of
of the World Ocean. The Aidanosagittidae family
mentioned elsewhere  should be considered as
MATERIALS AND METHODS
Plankton samples were collected using a standard
technique (a Juday net with a ring diameter of 37 cm),
in shallow depths, in the bights of the Peter the Great
Bay and the northwestern Sea of Japan. The holotypes
of chaetognaths are deposited in the collections of the
Paciﬁc Institute of Oceanology, Vladivostok, Russia.
Body is rather muscular and resilient,
not sagging if taken by forceps. Digestive diverticula
are present on midgut (trunk gut). Trunk gut is not vac-
uolated. Ciliary loop arises behind the level of eyes; its
trunk part is larger than the head part. The posterior pair
of lateral ﬁns is located on tail region rather than on
trunk region. Rays in the ﬁns are present, although there
are some rayless zones. Central nuclear zone of the eye
is pigmented and clearly demarcated from the periph-
Most known species of the genus inhabit tropical
and subtropical waters; several species have been found
in low boreal regions of the Sea of Okhotsk and Sea of
(Fig. 1A, B)
The reference number is AIS
7/1. It was found at Stn. 8, in the open part of Peter the
Great Bay, Sea of Japan (41
E), on Octo-
ber 21, 2005 (a cruise of RV
a water temperature of 6–7
C, in the horizon of 200–0 m;
the depth was 3500 m.
One paratype specimen was found on
October 21, 2005, at Stn. 4 (42
Fins of the ﬁrst pair and the small ante-
rior part of ﬁns of the second pair are devoid of rays.
Complete rays are present only in the tail ﬁn. Both the
tail part of the second pair of ﬁns and subenteric gan-
glion are longer than the trunk part of the second pair of
ﬁns (the former is 1.9 times longer than the latter).
of the holotype.
Body is rigid and
muscular. Head and trunk are equally wide. There is no
constriction in the area of seminal receptacles. The
specimen is at the third stage of maturity. Body is 6 mm
long. Tail region is 30.4% as long as the entire body.
Subenteric ganglion is relatively large, 11.8% as long
as the entire body, it is somewhat longer than the trunk
New Species of Arrowworms of the Genus
(Chaetognatha) from the Northwestern Part of the Sea of Japan
A. P. Kasatkina
Paciﬁc Institute of Oceanology, Far East Branch, Russian Academy of Sciences, Vladivostok, 690041 Russia
Accepted September 21, 2006
—This paper provides identiﬁcation keys for all known species of the genus
World Ocean. Detailed descriptions and original drawings are presented for four new species of
sp. n., and
sp. n. inhabiting Peter the Great
Bay and adjacent waters of the northwestern Sea of Japan.
Chaetognatha, Sea of Japan, fauna of