ISSN 10630740, Russian Journal of Marine Biology, 2011, Vol. 37, No. 2, pp. 132–142. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © E.V. Smirnova, N.P. Fadeeva, 2011, published in Biologiya Morya.
In the Sea of Japan the nematodes of the family
Tripuloididae Filipjev, 1918 occur rarely and thus are
poorly studied. Species of the genus
Cobb, 1894 are the most widely distributed members
of this family, occurring in the marine shallow sublit
toral sands. However, until now only one species of
this genus, namely
Cobb, 1894 has been
reported so far from Slavyanskii and Vostok bays of
Peter the Great Bay .
One of urgent targets of modern ecology is studies
of life cycles of different animals. Despite the great
species diversity of freeliving marine nematodes, this
aspect of their ecology is almost unstudied as yet. In
particular, no data are available so far concerning sea
sonal density dynamics and developmental patterns of
species of the genus
The purpose of this work was to describe a new spe
sp.n. and to study its life cycle and sea
sonal density dynamics in sandy sediments of shallow
bays in Russian waters of the Sea of Japan.
MATERIALS AND METHODS
The material was collected on sandy sediments of
shallow bights in the Sea of Japan as follows: Patrokl
Bight (Bosfor Vostochnyi Strait), Srednyaya Bight
(Vostok Bay) and Kievka Bight (Fig. 1). Altogether
380 specimens of the nematode were examined;
46 specimens were used for morphometric studies.
Seasonal fluctuations of density dynamics and
peculiarities of life cycles of the nematodes were stud
ied in semiclosed Patrokl Bight, on a sandy shallow, at
a depth of 0.7 m below the spring tide level. The sam
ples were collected every month, from October 2007 to
July 2009. Three samples were collected using a tubu
lar core sampler (5 cm high; sampling area of 20 cm
mostly during low tide, upon a quiet sea. Simulta
neously, we measured temperature and salinity in the
nearbottom water layer and temperature in the sur
veyed layer of sand using an EC METER CM21P
hydrological probe. To study the vertical distribution
of nematodes in the sediment column the samples
were collected during the first third of August 2009
using a 10 cm high core sampler with sampling area of
. Each the sampled sediment cores was then cut
into 1 cm thick layers.
The analysis of granulometric composition of the
sediment was performed in the Department of Soil
Science of Far Eastern Federal University (FEFU)
using the wet screen fractionation method with deter
mination of up to 12 different fractions. The fraction
ation of bottomsediment particles was performed
with either dispersion through sieves (for particles of
more than 0.1 mm in size) or the sedimentation
method (for particles that were smaller than 0.1 mm)
. The total carbon concentrations in the bottom
sediment samples (C
) were determined by Ass. Prof.
O.V. Nesterova (FEFU) using the Tyurin’s wet oxida
tion method .
To isolate living organisms from the sand, the sam
ples were rinsed by filtered seawater through a set of
sieves with mesh sizes of 80 and 20
m; each isolated
size fraction was then examined individually. Meio
Description and Life Cycle of
E. V. Smirnova
and N. P. Fadeeva
Far Eastern Fisheries and Technical University (Dalrybvtuz), Vladivostok, 690000 Russia;
Far Eastern Federal University, Vladivostok, 690091 Russia
Received September 30, 2010
sp. n. is described and illustrated. The new species resembles
Hopper, 1962 but differs from the latter by shorter setae, body and by the cindex and has three onchs in the
buccal cavity. The seasonal dynamics of abundance, proportion of adults and larvae, as well as the gravid and
nongravid females and males were studied. An elongated breeding season from April to November and a long
spring–summer peak of population density with a winter minimum at low temperatures for
characteristic in Peter the Great Bay.
: freeliving marine nematodes, the Sea of Japan,
, seasonal dynamics, life cycle.