1063-0740/02/2801- $27.00 © 2002
Russian Journal of Marine Biology, Vol. 28, No. 1, 2002, pp. 57–60.
Original Russian Text Copyright © 2002 by Biologiya Morya, Levin, Stepanov.
The study of the materials collected during the 1997
expedition of the Institute of Marine Biology at Cape
Sosunov (Sea of Japan) revealed a new species of
holothurian, the description of which is given below.
Levin et Stepanov,
sp. n. (Figs. 1–5).
Holotype: 9 cm long (ref. no. KNIRO-V-
004); Sept. 3, 1997, R/V
no. 20; stn. 14, 46
E (at Cape
Sosunov, Sea of Japan), 85 m depth; Sigsby trawl, coll.
by S.N. Fedorov. Paratype-1: 10 cm long (ref.
no. KNIRO-V-005); paratype-2: 10 cm long (ref.
no. KNIRO-V-006), same location. The type material
was deposited in the Kamchatka Research Institute of
Fisheries and Oceanography.
The species name is derived from the
structure of spermatozoa that distinguish this species of
Ten tentacles of equal size. The prevail-
ing type of spicule on the body skin are elongate perfo-
rated plates that taper toward one end and terminate in
a pointed spine (spines); openings are regularly spaced
(1–3 openings in transversal row); plates are abun-
dantly covered by tubercles, and their margin is
equipped with sharp teeth. In the introvert, there are
oval and elongate plates with smoothed margins, many
relatively small holes, and arched connectors between
the tubercles, which are virtually not found in other
The spermatozoa have a pecu-
liarity which is not typical of cucumariids, a conical
shape of the sperm head.
The body is cucumber-shaped. The
body skin is fairly thin, rigid. Skin (in preserved mate-
rial) is dark brown; tentacles are light brown. Ambu-
lacra are small, retractile, arranged in two rows pre-
dominantly along the radii.
There are ten tentacles of equal size. The oral disk is
about 1.5 cm in diameter. Retractor muscles are fairly
wide (5–8 mm in the broadened part), 2.0–3.0 cm long
in the preserved material, and are attached to the body
wall halfway down the length of the body. Longitudinal
muscles are 3–5 mm wide.
The stone canal is single, strongly twisted, about
5 mm long. The madreporite is somewhat elongate,
ﬂattened, 2–3 mm in diameter.
The holotype has two Polian vesicles arising from
the dorsal side of the circular ambulacral canal 1.2 and
3 cm long. Paratypes have a single vesicle 2.5 and
2.8 cm long, respectively.
The pharyngeal ring is weakly calciﬁed (Fig. 1). The
radial plates are about 14 mm high, have a wide base
with a deep notch at the posterior margin, and taper
A New Species of Holothurian from the Sea of Japan
V. S. Levin and V. G. Stepanov
Kamchatka Research Institute of Fisheries and Oceanography, Petropavlovsk-Kamchatskii, 683000 Russia
Received September 26, 2001
—A description of
sp. n. is given. It differs from other species of the
by the shape of spicules on the body skin and by the introvert, as well as sperm, morphology.
, new species, Sea of Japan.
The pharyngeal ring (length of dimension line is