ISSN 10630740, Russian Journal of Marine Biology, 2010, Vol. 36, No. 2, pp. 154–156. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © Yu.N. Poltev, 2010, published in Biologiya Morya.
Adult females of
sucking parasites in the gills of their final hosts, various
species of northern Pacific fishes, among them
. The typical place for the localiza
tion of this parasite is the branchial arches of the fish.
In this article, a different localization of
a fish host is reported.
Material was collected in the course of research on
the fishing seiner
off the eastern coast of
the northern Kuril Islands on April 14–23, 2008 at
nearbottom depths of 330–430 m (49
3 E) and 216–233 m (50
4 N, 156
4 E). The sampling gear
was a midwater trawl with vertical and horizontal
extensions of 50 and 200 m, respectively. In all,
3498 specimens of walleye pollock were examined
during the cruise.
This study showed that the parasitic copepod
was mainly attached to the second branchial
arch, in 71.4% of the fish. The proportion of fish with
a parasite on other branchial arches was 15.6% on the
third; 7.8% on the fourth; and 2.6% at the location of
the connection of the second and third branchial
arches (see table). In most cases (61.0% of the fish),
were attached to the left side
of the fish.
In two specimens of walleye pollock (2.6%),
was found localized on the isthmus. One
fish, 47 cm long, was caught on April 15 at a site with
depths of 345–367 m (49
6 N, 155
E). The parasite was alive; however, the fish
looked exhausted. Unfortunately it was impossible to
The article was translated by the author.
preserve and weigh it. Another fish, a postspawning
female pollock 49 cm long with a weight of 650 g, was
captured on April 25 at a site with depths of 200–
233 m (50
4 N, 156
The parasitic copepod formed connective tissue
around its cephalothorax (Fig. 1), which, as indicated
by previous studies [1, 2], accompanied the penetra
tion of the parasite into the heart. No negative effects
were observed on the sexual maturation and body
weight of the female specimen of walleye pollock.
Other postspawning females of the same length had a
similar body weight: 550 g (one specimen), 600 g
(three specimens), 650 g (seven), and 700 g (three
specimens) (the average body weight was 643 ±
11.6 g). Thus, the body weight of most of the weighed
female walleye pollock was either not different from
An Unusual Localization of the Parasitic Copepod
Wilson, 1917 (Copepoda: Pennellidae) on the Walleye
Yu. N. Poltev
Sakhalin Research Institute of Fisheries and Oceanography, YuzhnoSakhalinsk, 693016 Russia
Received September 15, 2009
—During a study performed in April 2008 in the Pacific waters of the northern Kuril Islands, the par
was found localized on the isthmus of two specimens of the walleye pol
. In both cases, the parasite directly penetrated the heart, without entering the
, Pacific waters, northern Kurils.
The external appearance of a
that penetrated the walleye pollock heart. a, heart; b, con
nectivetissue capsule formed around the front part of the
cephalothorax of the parasite; c, part of the parasite in the
skin; d, chitinized part of the parasite on the exterior.