Volume 8, Number 2
Published online 3/02/2012
The evidence of metamery in
adult brachiopods and phoronids
Elena N. Temereva, Vladimir
V. Malakhov
1
Department of Invertebrate Zoology, Biological
Faculty, Moscow State University, Moscow 119992, Russia.
2
Laboratory of Biology of Marine Invertebrates, Far
East Federal University, Vladivostok 690014, Russia.
ABSTRACT: There are both
metameric and nonmetameric animal body plans in each of the three main branches
of the bilaterian tree – the Ecdysozoa, the Deuterostomia and the Lophotrochozoa.
Has metamery originated independently in these groups or is it a synapomorphy of
all Bilateria? If the latter is correct, we might expect to find remnants of
metamery in nonmetameric forms. The Lophophorata seems to be the only group of
main bilaterian groups that lacks metamery. Here, we infer that the lateral
mesenteries of brachiopods and phoronids are metameric in nature and originated
from dissepiments between segments of trunk coelomic sacks of an oligomerous
ancestor. In addition to preoral and lophophore coeloms, brachiopods and
phoronids demonstrate a metameric subdivision of the body coelom. The trunk
coelom of recent brachiopods and phoronids is a product of partial fusion of
three or two segments, respectively. The lateral mesenteries in phoronids and
brachiopods bear funnels of excretory organs like the dissepiments of true
metameric animals (for example, annelids). In both groups, the lateral
mesenteries are situated at an angle to the main axis of the body and always at
a right angle to the axis of metamery. We conclude that metamery was present in
ancestral Lophrophotrochozoans and in the common ancestor of all Bilateria but
has since been reduced in some groups. The reduction of metamery in phoronids
and brachiopods is correlated with strong changes in their body plan. We suggest
that lophophorates are primitive lophotrochozoans because they retained some
plesiomorphic features.
KEY WORDS: Lophotrochozoa,
phylogeny, lateral mesenteries, metamorphosis, body plan.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
A new species of
Rhodinicola (Copepoda: Clausiidae), parasitic copepod of the shell-boring
polychaete Polydora brevipalpa (Annelida: Spionidae) from the Sea of
Japan
Tagea K.S. Björnberg1,
Vasily I. Radashevsky2
1 Centro
de Biologia Marinha, Universidade de São Paulo, C.P.
71, 11600-000, São Sebastião,
SP, Brasil.
2 A.V.
Zhirmunsky Institute of Marine Biology, Far Eastern Branch of the Russian
Academy of Sciences, 17 Palchevsky Street, Vladivostok 690041, Russia.
3 Far
Eastern Federal University, 8 Sukhanov Street, Vladivostok 690091, Russia.
Abstract:
The new clausiid copepod Rhodinicola polydorae sp.n. is an ectoparasite
of a spionid polychaete Polydora brevipalpa Zachs, 1933 in Peter the
Great Bay of the Sea of Japan (East Sea). The host polychaete bores into shells
of the Yesso scallop Mizuhopecten yessoensis (Jay, 1857). This is the
first report of annelidicolous copepods from the Sea of Japan (East Sea) and the
first description of a copepod parasitic on spionid polychaetes from Asia.
Key words:
clausiid copepod, annelidicolous parasite, adult morphology.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Parastylodactylus
matsuzawai sp.n. (Caridea: Stylodactylidae), a new
shrimp from Japanese waters
R.N. Burukovsky
Kaliningrad State
Technical University, Kaliningrad 236000, Russia.
ABSTRACT:
Parastylodactylus matsuzawai sp.n., is described from Japanese waters
and is close to P. semblatae Cleva, 1990. Both species feature rounded
pleura of abdominal somites, a tiny supraorbital spine, and five pairs of dorsal
spines on telson. It differs from P. semblatae by the armature of the
dorsal side of the rostrum (30–39 spines in P. semblatae vs. 23 in P.
matsuzawai sp.n.), by the length of the antennular peduncles (1/3 of
scaphocerite length in P. semblatae vs. 1/2 in P. matsuzawai sp.n.),
as well as by the morphology and armature of the pereiopods 3–5. In P.
semblatae the ischio-meral suture is only present in pereipods 5, while in
P. matsuzawai sp.n. it is present in pereiopods 4 and 5. P. matsuzawai
sp.n. lacks a proximal spine on the ischiomerus of the 3rd pereipods,
which are armed with a single subdistal spine; the ischiomera of 4th pereiopods
have 3 spines, those of 5th pereiopods
2 spines (subdistal and median), whereas P. semblatae has only one
subdistal spine on the 4th pereiopods
and 3 spines in the distal ½ of ischiomerus of the 5th pereiopods.
The new species is also more reddish than P. semblatae.
KEY WORDS:
Parastylodactylus matsuzawai sp.n., new species, Japan.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Tenonia
elegans sp.n., a new polynoid species (Polychaeta) from the shelf of
north east Sakhalin Island, Sea of Okhotsk
Inna L. Alalykina
A.V. Zhirmunsky Institute
of Marine Biology, Far East Branch, Russian Academy of Sciences, Far Eastern
Federal University, Vladivostok 690041 Russia.
ABSTRACT: A new polynoid
species Tenonia elegans sp.n. is described from the shelf of north
east Sakhalin Island. Till now the genus Tenonia remained monotypical. It
is recorded for the first time for Sea of Okhotsk. The detailed description of
the new species is given and its differences from a closely related species are
shown: anterior pair of eyes situated in front of widest point of prostomium;
the presence of papillae on antennae, palps and cirri; tentaculophores with 3–4
stout, curved setae on anterior face. This new species differs also from T.
priops in possessing smaller sizes of eyes and less numerous setae in
parapodia.
KEY WORDS:
Polychaeta, Polynoidae, Tenonia elegans sp.n., morphology,
taxonomy, Sakhalin, Sea of Okhotsk.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Genetic diversity of
Eukrohnia hamata (Chaetognatha) in the South Atlantic: analysis of gene
mtCO1
D.N. Kulagin1,
A.N. Stupnikova1,
T.V. Neretina2,
N.S. Mugue3
1 P.P.Shirshov
Institute of Oceanology Russian Academy of Science, 36, Nakhimovsky prospect,
Moscow, 117997, Russia.
2 White
Sea Biological Station, Department of Biology Lomonosov Moscow State University,
P.O. Box 20, Glavpochtamt, Kandalaksha raion, Murmanskaya oblast 184042, Russia.
3 Russian
Federal Research Institute of Fisheries and Oceanography, 17 Verhnyaya
Krasnoselskaya, Moscow 107140, Russia.
ABSTRACT: Genetic
diversity and structure of the cosmopolitan chaetognath Eukrohnia hamata
became the object of our research. The material was partly collected in
the Atlantic Sector of the Sothern Ocean (17 specimens) and partly taken from
the GenBank NCBI (2 specimens from Arctica and 3 specimens from South East
Atlantic). All 22 specimens analyzed had unique haplotypes in their 5’ COI gene
fragment (“barcoding” region) mtDNA sequences. Four distinct lineages were
revealed by the phylogenetic analysis. These lineages (populations) had
significant genetic differences that made 7–13% of the nucleotide substitutions
and were geographically separated. The boundaries of their distribution are the
large-scale oceanic fronts. Antarctic population can be distinguished in the
Atlantic sector of the Southern Ocean to the south of the Polar Front in the
Antarctic zone. To the north of the Polar Front in the Polar Frontal Zone and
the Subantarctic Zone — Subantarctic population can be distinguished. Antarctic
Circumpolar Current maintains genetic homogeneity of the Antarctic and
Subantarctic populations of E. hamata within the whole Atlantic sector of
the Southern Ocean. Tropical population was distinguished to the north of the
Subtropical Front, but individuals of E. hamata from this lineage can
reach the Subantarctic Zone with the rings of the Subtropical Front.
KEY WORDS: Zooplankton,
chaetognaths, molecular phylogeny, the Atlantic Ocean, Southern Ocean.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Comments. Discussions.
(in English)
Download this paper as PDF file:
Pdf
Volume
8, Number 1
Published online 3/09/2011
Vladimir Ivanovich Biserov. 13.08.1951 – 31.10.1998, by N.M. Biserova
(in English)
Download this paper as PDF file:
Pdf
Âîñïîìèíàíèÿ î
Â.È. Áèñåðîâå, Â.Í. Ñòîëáóíîâà,À.Ê. Ãðèøàíèí
(in Russian)
Download this paper as PDF file:
Pdf
Ecology of the terrestrial and freshwater
tardigrades (Tardigrada): autecological aspect
A.M. Avdonina
The Russian Academy of Economics
and Public Administration under the President of the Russian Federation,
Vladimir branch, Gorkogo Str. 59A, 600017 Vladimir, Russia.
ABTRACT: This review generalizes the
autecological data on terrestrial and freshwater tardigrades for the 100 past
years, systematizing the research results showing the influence of the various
environmental factors on tardigrades and adaptations of these amazing animals.
Autecological researches help to understand the distribution of tardigrades in
recent conditions, and also show the potential of these animals. The
extraordinary tardigrade tolerance to ionizing radiation, high pressure and low
temperatures in the anhydrobiosis gives the key to solve the problem of organism
survival in extraterrestrial environments. In spite of the high tolerance to the
significant anthropogenic exposure, such as influence of transport emissions,
industrial pollution, cuttings, fires, etc., many among them change the
quantitative and qualitative composition of tardigradofauna. Therefore
Tardigrada can be used as biological indicators of air pollution, particularly
by the sulfur dioxide and the heavy metals.
KEY WORDS: tardigrades (Tardigrada),
ecology, autecology, ecological factor, moisture, oxygen, temperature, light,
altitude, radiation, food, space, anhydrobiosis.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Taxonomy and biogeography of tardigrades
using an integrated approach: new results on species of the Macrobiotus
hufelandi group
R. Bertolani1,
V. Biserov†2,
L. Rebecchi1,
M. Cesari1
1
Department of Biology, University of Modena and Reggio
Emilia, Via Campi 213/D, 41125 Modena, Italy.
2 Institute
of Inland Water Biology, Academy of Sciences of Russia, Borok, Yaroslavl
District, Russia
ABSTRACT: This study considers in a
new light a population already studied and tentatively attributed to
Macrobiotus cf. terminalis (Bertolani, Rebecchi, 1993), by joining
molecular approaches to the traditional, but indispensable, light microscopy,
and to scanning electron microscopy. Differences in animal and, above all, egg
shell morphology, and the peculiar cox1 sequence indicate that this
population clearly pertains to a new species, M. vladimiri sp.n., which
is here described. The results obtained can be considered as an example of how a
modern taxonomical and biogeographical research can be carried out on this
animal phylum and in general on the animals belonging to the so called
meiofauna, where characters bound to morphology are often very few. This is the
first tardigrade species to be described and barcoded contemporarily.
KEY WORDS: tardigrades, Macrobiotus,
DNA barcoding, cox1, biogeography, taxonomy.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Tardigrades in bottom meiofauna in
different waterbodies of the Upper Volga Basin
V.A. Gusakov
Institute for Biology of Inland Water,
Russian Academy of Sciences, Borok, Yaroslavl district, 152742, Russia.
ABSTRACT: This paper describes the
results of investigations of tardigrades as a part of meiobenthos in different
waterbodies (rivers, lakes, reservoirs) of the Upper Volga basin. To the present
time 21 species of freshwater Tardigrada have been found in the region. In the
investigated waterbodies the most widespread and numerous species were
Pseudobiotus megalonyx (Thulin, 1928), Isohypsibius granulifer Thulin,
1928, Dactylobiotus selenicus Bertolani, 1981 and Thulinia ruffoi
Bertolani, 1981. The first of them is met in the majority of biotopes. In the
reservoirs the tardigrades can make up over 50% of the total number and 30% of
meiobenthos biomass even at a high abundance of other organisms. The maximal
population density was registered for P. megalonyx in the Gorky Reservoir
— 225.7 thous. ind./m2 and
3.5 g/m2.
The seasonal and long term abundance dynamics of tardigrades (in the Rybinsk
Reservoir as an example) are complicated. In some years they are almost
completely absent in samples, in other — reach a significant amount. The maximal
number of tardigrades individuals occurs in mid March – late June. In different
years in this period 1–3 peaks of abundance are registered for various species,
the greatest — usually, in May at temperature ~12–15°C. Changes in the abundance
dynamics of the taxonomic group and separate species are similar both in
profundal and open inshore zone, hence they are determined, mainly, by climatic
factors. During the autumn-winter decrease of the reservoir level in the drained
and frozen sediments of littoral P. megalonyx, D. selenicus and
I. granulifer at mature age retain their vitality not less than for 7–11
weeks. The aggregated distribution in biotopes is typical for tardigrades,
apparently, owing to low motility. Even under similar living conditions the
density of populations differs by orders of magnitude. Because of considerable
fluctuations of tardigrades abundance by years, seasons, biotopes and «within»
similar biotopes long term investigations are necessary for obtaining reliable
data on their distribution and population dynamics in waterbodies.
KEY WORDS: Tardigrada, Upper Volga,
species composition, quantitative parameters, seasonal and long term dynamics.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Macrobiotus trunovae
sp.n., a new species of tardigrade from Russia
Vladimir Biserov†1,
Giovanni Pilato2,
Oscar Lisi2
1 Institute
of Biology of Inland Waters, USSR Academy of Sciences, Borok, Yaroslav District.
2 Department
of Animal Biology “Marcello La Greca”, University of Catania, Via Androne 81,
95124 Catania, Italy.
ABSTRACT: Biserov cited the new
species Macrobiotus trunovae sp.n. in a paper of 1996 before publishing
its description and, unfortunately, he died prematurely. The description of the
new species is finished here. M. trunovae sp.n. belongs to the
Macrobiotus hufelandi group and differs from most species of the group for
the large body size and, overall, for some characters of the egg which have
processes very close to one another, and the egg shell with dots sometimes
forming a very irregular reticular design.
KEY WORDS: Tardigrada, Macrobiotus
trunovae sp.n., Russia.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
The ultrastructure of the tardigrade
spermatozoon: a comparison between Paramacrobiotus and Macrobiotus
species (Eutardigrada)
L. Rebecchi, T. Altiero, A. Guidi
Department of Biology, University of
Modena and Reggio Emilia, Via Campi 213/D 41125 Modena, Italy.
Abstract: The spermatozoan ultrastructure was
investigated in three semiterrestrial eutardigrade species belonging to two
different genera of Macrobiotidae (Paramacrobiotus and Macrobiotus).
The spermatozoa of P. areolatus and P. richtersi are very similar
and are made by three regions, namely a long head, a short kidney-shaped middle
piece and a short tail with its terminal tuft. In both species the spermatozoa
are particularly long (up to 100 µm) and very thin. The peculiar length is due
to the remarkably developed head consisting of a cylindrical acrosome and a
weakly coiled nucleus increasing in width caudally. The presence of a long
nucleus, an electron-dense core of fibrils running parallel to the nucleus, as
well as nine outer electron-dense fibers around the proximal part of the axoneme
represents novelties in the ultrastructure of the tardigrade spermatozoa. These
structures, never described before for a tardigrade spermatozoon, could be
related to the movement of those extraordinary long male gametes of
Paramacrobiotus. The spermatozoon of M. harmsworthi too is
made up of three regions: the head, including the acrosome and nuclear region,
the middle piece and the terminally tufted tail. Nevertheless it is only 46–50
µm in length and the head, including a slightly tight helical nuclear region, is
similar in length to the tail. In all macrobiotid species here examined,
including those from literature, the spermatozoa within the was deferens always
appear folded, with the hinge located between the end of the head and the
beginning of the middle piece, thus resembling a long nutcracker. The use of
spermatozoan characters as phylogenetic information in tardigrades is also
discussed.
Key
words: Tardigrada, Macrobiotidae, Paramacrobiotus,
Macrobiotus, Spermatozoon, Ultrastructure, Phylogeny.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Marine tardigrade Halechiniscus
jejuensis Chang et Rho, 2002 (Arthrotardigrada: Halechiniscidae) found in
Vietnam
Alexei V. Tchesunov
Department of Invertebrate Zoology,
Faculty of Biology, Moscow State University, Moscow, 119991, Russia.
ABSTRACT: Halechiniscus jejuensis
Chang et Rho, 2002 is found and briefly described from a mangrove habitat in the
Nha Trang area, Central Vietnam. The species was originally described at the
southernmost point of the Korean Peninsula, hence the new find extends
considerably the geographic distribution of the species southwards to the
tropical zone. The Vietnamese specimens slightly differ from the Korean ones in
shape and number of the lateral body expansions. A peculiar feature of the
Vietnamese specimens is development of thread-like colonial prokaryotes on
ventral surface of the head.
KEY WORDS: Halechiniscus jejuensis,
marine tardigrades, mangroves, Vietnam.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Volume
7, Number 2
Published online 30/12/2010
Two new species of Pileolaria (Polychaeta: Spirorbidae)
from the Southern Hemisphere with a brief review of related species
A.V. Rzhavsky
A.N. Severtsov Institute of Ecology and Evolution, RAS,
Leninskij Prospekt 33, Moscow, Russia 119071
ABSRACT: Two new polychaete
species of family Spirorbidae are described, both similar to those species of
Pileolaria that have the distal part of the brood-chamber smooth and domed or
bilobed. Pileolaria connexa sp.n. from Kerguelen Island (and probably Palmer
Archipelago), unlike most species of the genus, commonly retains the primary
operculum (plate and talon) distal to the brood chamber, and has sickle chaetae
with unusually long distal serrated parts of the blades. Pileolaria invultuosa
sp.n. from Bouvet Island and Adelie Land (and perhaps Enderby Land and Signy
Island) sheds the primary operculum before the brood chamber is fully developed
and has distal serrated parts of sickle chaetae blades similar in length to
proximal thick parts of the blades. Both new species are similar, but unusual
amongst this group, in having a shallow calcified cap restricted to the distal
part of the brood chamber. The primary opercula of both species differ from each
other (and from those of most Pileolaria species) in the shape and position of
the distal plates talons.
KEY WORDS: Spirorbidae, Pileolaria, Antarctic,
Subantarctic.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
A description of Anoplostoma nhatrangensis sp.n. from
mangrove habitats of Nha Trang, Central Vietnam, with a review of the genus
Anoplostoma Bütschli, 1874 (Nematoda: Enoplida)
Alexei V. Tchesunov1,
Nguyen Vu Thanh2
1
Department of Invertebrate Zoology, Faculty of Biology,
Moscow State University, Moscow 119991, Russia.
2
Institute of Ecology and Biological Resources (IEBR), Vietnam
Academy of Science and Technology, 18 Hoang Quoc Viet Rd., 10000 Hanoi, Vietnam.
ABSTRACT: Anoplostoma nhatrangensis sp.n. is described
from a degrading mangrove habitat in the Nha Trang area, Central Vietnam. The
new species is characterized by relatively long outer labial setae (81–120%
c.b.d.); relatively long tail with longer posterior cylindrical portion (c
5.71–6.92, c’ 8.96–11.8, distal tail part 63–90%); males without preanal bursal
papillae and only a minute postanal bursal papilla besides the posterior bursal
spine. Anoplostoma nhatrangensis sp.n. is most similar to the A. heterurum
differing in certain morphometric values: a bit more stout body (a 33–45 versus
56), and relatively longer tail (c 5.9–6.6 versus 11 and c’ 10–12 versus 6.5)
with greater posterior slender cylindrical portion (82–90 versus 75%). A short
taxonomic review of the Anoplostoma species is proposed. The genus contains
twenty nominal species: fourteen of them are considered as valid; A.
brevispiculum is considered as a species incertae sedis because its characters
do not fit the generic diagnosis, A. demani as a species inquirenda because of
incomplete data of the original description and A. macrospiculum as a junior
synonym of A. sunderbanae. Tables of simplified images of male heads and tails
as well as list of important morphometric values are proposed as a tool for
quicker identification of Anoplostoma species.
KEY WORDS: Anoplostoma,
free-living nematodes, mangroves, taxonomy, Vietnam.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Micronephthys (Polychaeta: Nephtyidae) of Northern
Europe and Arctic
N.Yu. Dnestrovskaya, I.A. Jirkov
Moscow State University, Biological Faculty, Department of
Hydrobiology; Leninskie Gory, 1, bldg. 12, Moscow 119991, Russia
ABSTRACT: Three species of Micronephthys inhabit Northern
European and Arctic waters: Micronephthys minuta (Theel, 1879), M. neotena
(Noyes, 1980), and M. hartmannschroederae Jirkov et Dnestrovskaya, 2001. All
species are re-described, original illustrations and distribution maps accompany
all descriptions. Micronephthys minuta and M. neotena are a mainly Arctic and
boreal species, respectively, very abundant in brackish waters. Micronephthys
hartmannschroederae should be very abundant sporadically in boreal European
waters. The existing literature on biology and distribution of these species is
reviewed. The taxonomic characters used to separate genera within Nephtyidae are
analysed, proving that the family needs to be fully reviewed.
KEY WORDS: Polychaeta, Nephtyidae, Micronephthys, Northern
Europe, Arctic.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
The first record of parasitic nematode Clavinema mariae
(Dracunculoidea: Philometridae) in gadiform fishes (Osteichthyes: Gadiformes)
S.G. Sokolov1,
S.E. Frolova2,
E.V. Frolov2
1
A.N. Severtsov Ecology and Evolution Institute, Leninskiy pr.
33, Moscow 119071, Russia.
2 Sakhalin
Research Institute of Fisheries and Oceanography, Komsomolskaya str. 196,
Yuzhno-Sakhalinsk 693023, Russia.
ABSTRACT: Nematode Clavinema mariae has been found in
Pacific saffron cod Eleginus gracilis, caught in Izmenchivoye lagoon (Sakhalin).
This is the first report of this parasite from gadiform fishes. The new data on
location of dorsal oesophageal gland in this species has been obtained.
Diagnosis of the genus Clavinema has been adjusted.
KEY WORDS: Clavinema mariae, Dracunculoidea, Eleginus
gracilis, Philometridae.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Fine structure of nervous system in plerocercoid
Ligula intestinalis (Cestoda: Diphyllobothriidea)
N.M. Biserova, I.I. Gordeev
Department of Invertebrate Zoology, Faculty of Biology,
Lomonosov Moscow State University, Moscow 119991, Russia.
ABSTRACT: The fine structure of the nervous system in
plerocercoid Ligula intestinalis (Diphyllobothriidae) has been studied. The
ultrastructure of the cerebral ganglion, the main nerve cords and peripheral
nervous system has been described. The cerebral ganglion has complicated
microanatomy. It consists of symmetric pair frontal and lateral lobes connected
by the massive median commissure, and ventral azygos lobe, located in the center
and on the ventral surface of the commissure. Two crossed ventral nerves are
originated from the unpaired median (ventral) lobe. It was found, that the
neurons in the lateral lobes and the commissure have asymmetrical position
(localization neurons in the lateral lobes and the commissure has dorso-ventral
polarity): large neurons (20–40 µm) are concentrated on the dorsal surface of
the cerebral ganglion. We found four types of neurons with different fine
structure and size, peripheral neurosecretory cells and undifferentiated cells.
Three types of synaptic contacts have revealed in neuropiles. Giant axon
occurred as part of the main cord. On the surface membrane of the giant axon are
numerous incoming synapses. The peripheral nervous system consists of numerous
compact bunches of nerve processes taking place along the longitudinal and dorso-ventral
muscle fibers. Also three types of sensory organs were found in the tegument:
one type a ciliate and two types unciliate receptors. Comparative analysis of
nervous system organization in representatives of the two orders
Diphyllobothriidea and Bothriocephalidea showed that the cerebral ganglion L.
intestinalis possesses bilateral symmetry, characterized by the presence of the
ventral lobe, ventral nerves and the dorso-ventral polarity in the arrangement
of neurons and exiting nerves. On the contrary, the cerebral ganglion of
Triaenophorus nodulosus (Bothriocephalidea) has a double-beam symmetry: it has
symmetrical lobes in ganglion with symmetrical dorsal and ventral nerves, lack
of lobe in the median commissure, and send symmetrical dorso-ventral rootlets in
the bothria. Our data confirm the belonging of the studied species to different
groups and support the idea of separation Pseudophyllidea sensu lato into two
new orders Diphyllobothriidea and Bothriocephallidea.
KEY WORDS: platyhelmintes, tapeworms, nervous system,
ultrastructure, symmetry, polarity, neuron, synapse, Cestoda, Diphyllobothriidea,
Ligula intestinalis.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Cladocera (Crustacea: Branchiopoda) in Indian hot
water springs
S. Padhye1,
A.A. Kotov2
1 Laboratory
for Zooplankton Studies, Dept. of Zoology, University of Pune, Pune-411007,
India.
2 A.N.
Severtsov Institute of Ecology and Evolution, Leninsky Prospect 33, Moscow
119071, Russia.
ABSTRACT: We found two species of Cladocera (Crustacea:
Branchiopoda), namely Latonopsis cf. australis Sars, 1888 (family Sididae) and
Alona cambouei Guerne et Richard, 1893 (family Chydoridae), in the Unhere hot
water springs near Pali, State of Maharashtra, India at temperatures of
34.5–36.7 °C. Our finding is the first record of cladocerans with exact species
determination in hotsprings of the Oriental zone.
KEY WORDS: Anomopoda, fauna, India, abiotic factors,
temperature.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Structure and differentiation of the tissues of
cysticercoids. 3. Differentiation of the endocyst of typical diplocyst of
Aploparaksis bulbocirrus (Cestoda: Aploparaksidae)
V.P. Nikishin
Institute of the Biological Problems of the North,
Portovaya Str. 18, 685000 Magadan, Russia.
Abstract: Fine structure of endocyst of the developing and
young cysticercoid Aploparaksis bulbocirrus Deblock et Rausch, 1968, referring
as “typical diplocyst” has been studied. It was shown that a cavity for
invaginated scolex and neck, was formed de novo. During cystogenesis tegument,
muscle elements, excretory system, inner boundary of endocyst and secretory
cells, were differentiated. Muscular cells form both muscles and fibrous layers
located between distal cytoplasm of tegument and cellular layer. Fibroblasts and
nervous elements were not identified. Full formation of endocyst’s wall
including formation of glycocalix layer, modification of microvilli and distal
cytoplasm of tegument took place after invagination of scolex and neck into its
cavity. The results confirm our consideration about endocyst as a defensive
structure adapted to mechanical and chemical actions in the initial part of
digestive tract of their definitive host.
Key words: cysticercoid, typical diplocyst, ultrastructure,
development, first invagination, scolexogenesis, endocyst.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Volume 7, Number 1
Published online 30/12/2010
Three new interstitial species of
Remaneicaris Jakobi, 1972 (Copepoda: Harpacticoida: Parastenocarididae) from
Southern and Southeastern Brazil
Paulo H.C. Corgosinho1,
Pedro Martinez Arbizu2,
Edinaldo N. dos Santos-Silva3
1,2DZMB
— Forschungsinstitut Senckenberg, Sudstrand 44, 26382
Wilhelmshaven, Germany.
1 Center
Unesco/HIDROEX (International Center ror Education, Capacity Building and
Applied Research in Water), Frutal (MG), Brazil.
3Plankton
Laboratory, CPBA/INPA, Av. Andre
Araujo, 2936
Petrópolis,
69011-970, Manaus-AM, Brazil.
ABSTRACT: Three new species of the
genus Remaneicaris from Southern and Southeastern Brazil are described. The new
species are closely related to R. analuizae, R. euniceae, R. tageae and R. divae,
sharing the presence of a hyaline margin on the 9th segment of male antennule.
Remaneicaris itacambirucui sp.n., R. insolitus sp.n. and R. ivoneae sp.n. differ
by: number of integumental windows on the 2nd and 5th urosomites; ornamentation
of the telson, with postopercular ornamentation shared by R. insolitus sp.n. and
R. itacambirucui sp.n.; shape of the swimming leg 3 exopod and armature of the
swimming leg 3 endopod, with straight exopod and unarmed endopod shared by R.
insolitus sp.n. and R. ivoneae sp. n.; and morphology of the swimming leg 4
endopod with a similar condition shared by R. insolitus sp.n. and R.
itacambirucui sp.n. Remaneicaris itacambirucui sp.n. seems to be closely related
to R. ivoneae sp.n. with which it shares the presence of a hyaline inner margin
on the outer spine of male’s swimming leg 3. Remaneicaris insolitus sp.n. seems
to be closely related to R. divae, sharing a continuous transversal row of
spinules on the antero-ventral margin of the telson. In the absence of more
informative characters, the exact phylogenetic position of R. itacambirucui sp.n.
and R. ivoneae sp.n. within a monophyletic group of species closely related to
R. analuizae is difficult to determine.
KEY WORDS: Copepoda,
Parastenocarididae, Remaneicaris, new species, Brazil.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Proales tillyensis sp.n. (Monogononta: Proalidae), a
new rotifer species from North-West Germany, with reconstruction of its somatic
musculature
E.F. Wilts, W.H. Ahlrichs
Systematics and Evolutionary Biology, Department of
Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg,
26111 Oldenburg, Germany.
ABSTRACT: We here describe a new proalid rotifer species
Proales tillyensis sp.n. from Oldenburg, North-West Germany. The species was
initially found in the ph-neutral water of Lake Tilly in August 2006. Its
description is based on light and electron microscopy, providing different views
of both the whole specimen and its trophi. Additionally, the body musculature of
the species was visualized by confocal laser scanning microscopy using
fluorescent-labelled phalloidin and compared with the musculature of other
Proales species. Proales tillyensis sp.n. resembles P. fallaciosa Wulfert, 1937
and P. decipiens (Ehrenberg, 1832) but differs in its ecology. Furthermore it
can be diagnosed from the former species by the absence of a knob-like
projection between the toes, the small body size, the number of uncus teeth and
the organization of body musculature. From the latter species it can be
diagnosed by the number of uncus teeth, the small body size and the lack of a
constriction between stomach and intestine.
KEY WORDS: Proales tillyensis sp.n., Rotifera, Proalidae,
CLSM, somatic musculature.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
A new psammophilic species of the genus
Diacyclops (Crustacea: Cyclopoida) from the littoral zone of Lake Baikal (East
Siberia)
Natalya G. Sheveleva1,
Oleg A. Timoshkin, Viacheslav N. Aleksandrov, Ekaterina P. Tereza
Limnological Institute of Siberian
Branch of Russian Academy of Sciences, Ulan-Batorskaya, 3, 664033 Irkutsk,
Russia.
ABSTRACT: An illustrated description
of Diacyclops zhimulevi Sheveleva et Timoshkin, sp.n. (Crustacea, Cyclopoida:
Cyclopidae) is provided. The new species is widely distributed along the
southwestern coast of Lake Baikal, inhabiting sandy bottoms of the shallow
littoral zone. A comparison is made with the previously studied and closely
related species Diacyclops eulitoralis Alekseev et Arov, 1986 from the sandy
interstitial environment of Lake Baikal. The new species differs from its most
closely related species D. eulitoralis by a combination of characters: shorter,
nearly square caudal furca (furcal index 1:1 in contrast to 1:3.5 in D.
eulitoralis), a larger number of antennular segments, and a different segment
pattern of the swimming legs: 2.2/3.2/3.3/3.3 compared to 2.2/3.2/3.2/3.2 in D.
eulitoralis. The armament of the distal endopodal segments of the swimming legs
1 and 2 is generally characterized by presence of a long and stout apical spine.
The two species are also clearly divergent in ecology: D. eulitoralis inhabits
the upper surf zone of the beach and may fairly be called an interstitial
species (Alekseev & Arov, 1986; Boxshall et al., 1993), whereas the new species
colonizes sandy bottom of the littoral zone.
KEY WORDS: Diacyclops zhimulevi
Sheveleva et Timoshkin, sp.n., Cyclopoida, Cyclopidae, Lake Baikal, psammon.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Ultrastructural study of spermatogenesis in the Pacific
oyster Crassostrea gigas (Bivalvia: Ostreidae) from the Sea of Japan
O.V. Yurchenko, V.I. Radashevsky, A.A. Reunov
A.V. Zhirmunsky Institute of Marine Biology, FEB RAS,
Vladivostok, 690041, Russia.
ABSTRACT: Spermatogenesis in the Pacific oyster
Crassostrea gigas from the Sea of Japan, was studied with transmission and
scanning electron microscopes. Spermatogonia are characterized by two kinds of
nuage-like material (large germinal body-like structure and/or cluster of small
globules), cisternae of endoplasmic reticulum and prominent Golgi body that
gives rise to occasional proacrosomal vesicles. Spermatocytes contain numerous
proacrosomal vesicles, while both kinds of nuage-like material are rarely
observed at this stage. A large single acrosomal vesicle is formed by fusion of
proacrosomal vesicles in the basal part of each spermatid. After migration to
the apical position of the acrosomal vesicle becomes cup-shaped; the round
nucleus assumes barrel-like outlines. Part of spermatocytes and spermatids
develop with flagellum while some spermatogenic cells are characterized by
intracellular axoneme. Spermatozoa have an electron-lucent knob situated on top
of the acrosome. This type of knob has never been described earlier in the C.
gigas and other ostreids. The pattern of C. gigas spermatogenesis which includes
many ultrastructural features may be used in future comparative studies of sperm
development in Ostreidae and other mollusks.
KEY WORDS: Crassostrea gigas, Ostreidae, sperm cells,
ultrastructure.
(in English with Russian Summary)
Download this paper as PDF file:
Pdf
Biology of the shrimps Sergia regalis (Gordon, 1939)
(Crustacea: Sergestidae) in waters of Namibia
R.N. Burukovsky
Kaliningrad state technical university, 236000
Kaliningrad, Russia.
ABSTRACT: The circumtropical species
Sergia regalis belongs to the
mesopelagic strongly migratory species. In Namibia waters (South-East Atlantic)
these shrimps feed on the euphausiids, radiolarians and copepods which form
28,5, 30,9, 32,7% of volume of virtual bolus respectively. At the early stages
of ontogenesis S. regalis is a grazing plankton feeder-predator which feeds
mainly on copepods and small radiolarians (micro- and mesoplankton). Having
grown up, the feed on predatory euphausiids including
Nematoscelis megalops (macroplankton) thus becoming
aggressive plankton predator. S. regalis
is a member of grazing food chain. These shrimps are basic objects of feeding
objects for the fish Merluccius polli
oss Angola. S. regalis
provides 18% of Merluccius polli
virtual bolus weight.
KEY WORDS: plankton, food chains, Sergia regalis,
distribution, biology, feeding, hunting mode.
(in Russian with English Summary)
Download this paper as PDF file:
Pdf
Other Issues |
