Stenosemus nitens sp. nov.;
pp. 87 -

A new deep-water polyplacophoran, Stenosemus nitens sp. nov., from Papua New Guinean waters is described. It differs from other species of the genus Stenosemus by having a sculptureless, smooth and shiny surface of the tegmentum, smooth dorsal spicules with only a few small transverse wrinkles on top, and unusual bends of the front margin of the intermediate valves. Within the genus the new species belongs to a limited group of coloured chitons.

Хитон с блестящей раковиной (Mollusca: Polyplacophora) из глубоких вод у Папуа Новой Гвинеи
Сиренко Б.И. ;
microvilli; cilia; Caenogastropoda;
pp. 93 -

Cellular composition and morphology of components of photoreceptor apparatus of the retinae of camera eyes of some species of terrestrial gastropod pulmonate molluscs were studied and its evolutionary transformations were traced. It was demonstrated that all examined characteristics of photoreceptor apparatus of the most investigated species were normal for terrestrial pulmonates, while those of one species were special. Evolutionary transformations of photoreceptor apparatus of terrestrial pulmonate molluscs due to habitat shift were quite significant and concerned of its cellular composition and morphology of photoreceptor cells.

Клеточный состав, морфологическая характеристика и эволюционные изменения фоторецепторного аппарата камерных глаз наземных брюхоногих моллюсков (Heterobranchia, Stylommatophora)
Шепелева И.П.;
intraspecific; polymorphism; quantitative indicators; thickness; valves; weight;
pp. 103 -

The morphological variability of the bivalve mollusc Flexopecten glaber was studied based on the analysis of 306 specimens from the Kazach’ya Bay (Sevastopol, Crimea) of the Black Sea. The sampling of mollusks was carried out with the help of skuba equipment in June–September of 2017–2018. For F. glaber, the age and size characteristics are given and the main trends in their ratios with the shell growth are considered. For the first time, quantitative indicators of thickness of the shell valves, their weight and height of the radial ribs are presented and discussed. A wide intraspecific polymorphism of the shell is shown in a relatively narrow range of habitat conditions. The obtained data expand the understanding of the morphological variability of F. glaber in the Black Sea and provide new information on the functional morphology of the species.

Новые данные о морфологической изменчивости раковины Flexopecten glaber (Linnaeus, 1758) (Bivalvia, Pectinidae) в Чёрном море
Бондарев И.П.;
Fresh-water and brackish-water species; type series; diversity; taxonomy; nomenclature; Black Sea; Caspian Sea;
pp. 115 -

An illustrated overview of the type series of nominal taxa of the gastropod genus Theodoxus (Neritidae) inhabiting the Ponto-Caspian region is presented. It is made on the basis of a revision of large European malacological collections and includes descriptions of the type specimens of 16 taxa of different rank (species, variety, morph). Apart of these, the “type” specimens of four taxa with unavailable names have been traced in ZIN collection; we illustrate them to show the variability of Ponto-Caspian Theodoxus. In most cases, the photographs of the type specimens are published for the first time. We provide a taxonomic analysis of all studied type series, with comments on the nomenclature, systematic position and taxonomic rank of all nominal taxa of Theodoxus recorded from the Ponto-Caspian area.

Обзор видов рода Theodoxus (Gastropoda: Neritidae) Понто-Каспийского региона с рассмотрением доступного типового материала
Анистратенко В.В.; Ситникова Т.Я.; Кияшко П.В.; Винарский М.В.; Анистратенко О.Ю.;
Bivalvia; Sphaeriidae; fauna; distribution; ecology; Urals;
pp. 135 -

The article is devoted to the fauna of Bivalvia (family Sphaeriidae) of waterbodies and watercourses of the eastern slope of the Polar and Pre-Polar Urals. The fauna of freshwater clams of this region remains practically unexplored. This study aimed at identification of the species content of Bivalvia and publication of images of their shells. We analyzed both qualitative and quantitative samples of molluscs as well as fish stomach contents. The identification of the material was based on conchological features, including the hinge structure. In total, 31 sphaeriid species is reported, and the annotated check-list, brief zoogeographic characteristics of the fauna, and shell images are provided. Most species demonstrate a limited spatial distribution within the studied area. The causes of discrepancies between published lists of sphaeriid species are discussed.

Материалы к фауне пресноводных двустворчатых моллюсков водоемов и водотоков восточного склона Полярного и Приполярного Урала
Андреева С.И.; Андреев Н.И.; Бабушкин Е.С.;;
Phaedusinae; taxonomy; new species; Caucasus;
pp. 149 -

Pontophaedusa gregoi sp. nov. is described from the Imereti Region of Georgia. This is the second species of a Tertiary relict genus that represents a very early diverged lineage of the Phaedusinae subfamily. The differences between the shell characters and climatic preferences of the Pontophaedusa species are discussed.

Второй существующий вид рода Pontophaedusa Lindholm, 1924 (Gastropoda, Pulmonata, Clausiliidae) из Грузии
Мумладзе Л.; Секереш М.;
Hernández Quinta M.; Bauzá Hernández M.A.; Franke S.; Fernández Velázquez A.;
pp. 155 -

A new genus and species of Cepolidae are described from the Island of Cuba: Plagiosimilis gibarensis gen. et sp. nov. It is classified in Cepolidae based on the following diagnostic characteristics of the family: dart apparatus consisting of a dart sac with a pedunculated gland on its apical side, both covered by a sheath; at the base of the dart apparatus there are two accessory glands; absence of a diverticulum. The specimens from the new genus come from the northern part of the Holguin province in the vicinity of the town of Gibara and live in special habitat dominated by Tillandsia plants. Shell with the rounded last whorl last very globular round, circular umbilicus and strongly reflected lip distinguish conchologically the new genus. The reproductive system and the shell differ from the other genera, although it have a certain similarity with the genera Plagioptycha and Hemitrochus.

Новый род и вид Cepolidae is Кубы (Pulmonata, Helicoidea)
Эрнандес Куинта М.; Бауза Эрнандес М. А.; Франке Ш.; Фернандес Веласкес А.;
taxonomy; Dien Bien; Vietnam;
pp. 165 -

A report is given on the genus Rhiostoma (Cyclophoridae) collected in Vietnam during recent fieldwork. Locality data, Vietnam distribution and general distribution are given for each species, including references to previously published records. Five named species are listed, of which a new species is described, Rhiostoma ningbien sp. nov., from Dien Bien, North-western Vietnam.

Наземные моллюски рода Rhiostoma Benson, 1860 из Вьетнама (Gastropoda: Caenogastropoda: Cyclophoridae) с описанием нового вид
До Д.С.; Нгуен Т.С.; До Х.Л.;
Septibranchia; Anomalodesmata; predaceous molluscs; morphology; new species;
pp. 173 -

The family Lyonsiellidae comprises carnivorous bivalve molluscs, distributed worldwide from sublittoral to ultraabyssal depths. One of the key anatomical characters of lyonsiellids is the reduction of the gill filaments in size and number and an increase of amount of muscles and connective tissue in gills, so their ctenidia represent an intermediate stage between eulamellibranch and septibranch conditions. The family Lyonsiellidae presently includes four genera: Lyonsiella, Allogramma, Policordia and Dallicordia. Taxonomy of the family is still problematic at both generic and species levels. The genus Dallicordia, typified by Lyonsiella alaskana was established on the assumption that it has no gills but possesses a muscular septum pierced by ostia, in contrast to the other lyonsiellids that have filamentous gills. Additionally, Lyonsiella uschakovi and Policordia ochotica were tentatively assigned to the new genus. Later P. ochotica was synonymized with P. media. In this paper we show that actually the Dallicordia was typified by an undescribed species misidentified as Lyonsiella alaskana which we describe here as D. bernardi sp. nov. Taxonomic position of the genus is dubious and could be clarified only after additional anatomical data on its type species becomes available. On the basis of examination of the type material of P. ochotica and images of the holotype of P. media, we reinstate the species P. ochotica. For the first time photographs of the holotype of L. uschakovi are provided for this specimen that was previously considered lost. Given the current state of knowledge we propose to consider species L. alaskana, L. uschakovi and P. ochotica in frame of the genus Policordia, for which we provide a list of all 29 species described up to date.

Статус рода Dallicordia и состав глубоководных хищных двустворчатых моллюсков рода Policordia (Bivalvia, Verticordioidea, Lyonsiellidae)
Сафонова Л.А.; Крылова Е.М.;
Nudibranchia; Flabellinidae; Coryphellina; integrative taxonomy; species complex; cryptic species;
pp. 183 -

Flabellina rubrolineata was believed to have a wide distribution range, being reported from the Mediterranean Sea (non-native), the Red Sea, the Indian Ocean and adjacent seas, and the Indo-West Pacific and from Australia to Hawaii. In the present paper, we provide a redescription of Flabellina rubrolineata, based on specimens collected near the type locality of this species in the Red Sea. The morphology of this species was studied using anatomical dissections and scanning electron microscopy. To place this species in the phylogenetic framework and test the identity of other specimens of F. rubrolineata from the Indo-West Pacific we sequenced COI, H3, 16S and 28S gene fragments and obtained phylogenetic trees based on Bayesian and Maximum likelihood inferences. Our morphological and molecular results show a clear separation of F. rubrolineata from the Red Sea from its relatives in the Indo-West Pacific. We suggest that F. rubrolineata is restricted to only the Red Sea, the Arabian Sea and the Mediterranean Sea and to West Indian Ocean, while specimens from other regions belong to a complex of pseudocryptic species.

Молекулярно-генетический анализ и обновленное таксономическое переописание Flabellina rubrolineata (Nudibranсhia: Flabellinidae) из Красного и Аравийского морей
Екимова; И.А.; Антохина Т.И.; Щепетов Д.М.;
Culcita novaeguineae; Linckia laevigata; symbiosis; parasitism; stable isotopes analysis; diet;
pp. 195 -

The trophic relationships between two species of symbiotic gall-forming molluscs from the genus Stilifer (family Eulimidae) and two of their hosts-asteroid species, Linckia laevigata and Culcita noveaguineae, were investigated using the stable isotope analysis of carbon and nitrogen. The aim of present study was to identify the most preferable host tissue in the symbionts’ diet. We analyzed δ15N and δ13C values in tube-feet, gonads and digestive glands of the hosts-starfishes and in muscles of the molluscs. Both symbiont species did not differ to each other both in δ15N and δ13C values. The average δ15N and δ13C values of Stilifer variabilis were significantly different from the digestive glands and gonads of their host Culcita novaeguineae and did not show differences from the tube-feet of starfishes. A similar pattern was found in the symbiotic association of Stilifer utinomi and Linckia laevigata. The tube-feet of analyzed starfishes had significantly higher average δ15N and δ13C values than the digestive glands and gonads. Obtained isotopic signatures indicate that symbionts do not feed on the host’s tissues, but take nutrients from their digestive system. It seems that the proboscis of Stilifer spp. absorbs the nutrients from the digestive system of the host-starfish thereby not disturbing significantly the host’s immune system.

Трофические взаимодействия между галлообразующими моллюсками рода Stilifer (Gast­ropoda, Eulimidae) и их хозяевами (Echinodermata)
Мехова Е.С.; Дгебуадзе П.Ю.;
pp. 203 -

Gastropod Aporrhais pespelicani was recently recorded for the first time in several localities along the Murman Coast (SW Barents Sea). In all areas, only single specimens were collected with the exception of Kislaya Inlet where the dense population was found. We repeated field study in the Kislaya Inlet decade later after the first findings of the species. No living specimens were found at the place of the previous habitat of the population of Aporrhais pespelicani, however, two adult snails were collected in a remoted locality from the same waterbody. We hypothesize that distribution of Aporrhais pespelicani in the its northern edge of range fit to “core-satellite” metapopulation model, where Murman local populations representing “satellites” of the Norwegian “core”. There is no evident proof on the relation of recent records of Aporrhais pespelicani with range extension due to the climate change, as it was suggested before.

Странники северных берегов: распространение Aporrhais pespelicani (Gastropoda: Stromboidea) в Баренцевом море
Нехаев И.О.; Зуев Ю.А.; Русяев С.М.;
pp. 207 -

A relict and endemic species of the Blue Nile drainage basin, the mussel Unio abyssinicus, is under the threat of extinction, with the continuing decline in the area, while data on the localities and biology of the mollusc are scarce. A new find of the mollusc population in the Duko river, located in the Oromiya Region of south-western Ethiopia, gives additional information about distribution of this species. The morphology of siphons of U. abyssinicus has been studied for the first time, the features of siphonal papillas are compared with those of the other mussel species. The data on the beak sculpture as well as the morphology of the hinge teeth have been clarified. Some new data on biology of the mussel are provided.

Новые данные о морфологии перловицы Unio abyssinicus (Bivalvia: Unionidae) из Эфиопии
Саенко Е.М.;
pp. 216 -

A new replacement name Gallardochiton nom. nov., is hereby proposed to solve the homonymy between the polyplacophoran genus Gallardoia Sirenko, 2007 and the insectean genus Gallardoia Bruch, 1924.


Замещающее название для преоккупированного рода полиплакофор  Gallardoia Sirenko, 2007 (Mollusca)
Сиренко Б.И.;
Schileyko А.; Pazilov А.; Abdulazizova Sh.;
pp. 217 -

Description of Neofruticicola donum gen. et sp. nov. from Kugitangtau Range (Central Asia) has presented. Conchologically the new species is similar to Fruticicola perlucens (Rosen, 1901), but anatomically it represents an unique for Bradybaenidae case of partial reduction of accessory organs of female part of the reproductive tract.

Ещё один сюрприз от Bradybaenidae (Gastropoda, Pulmonata)
Шилейко А.; Пазылов А.; Абдулазизова Ш.;
pp. 1 -

Vietnam with its limestone ranges that are concentrated mainly in northern, north–central and southern parts, and many different limestone islands running along the coastline, has a phylogenetically-diverse land snails fauna dominated by endemic species. The genus Cyclophorus (Cyclophoridae) in Vietnam is studied. Sixty species and subspecies from various habitats of limestone areas throughout Vietnam are confirmed and recorded. New species and subspecies, Cyclophorus implicatus kanhoensis ssp. nov., from Northwestern Vietnam, and Cyclophorus tamdaoensis sp. nov., from Northern Vietnam are described and discussed. In this paper, the Cyclophorus courbeti var. leucostoma Dautzenberg et Fischer, 1905, is elevated to subspecies.

Семейство Cyclophoridae во Вьетнаме (Gastropoda: Cyclophoroidea): род Cyclophorus Montfort, 1810
До Д.С.; До В.Н.;
Middendorffinaia; Nodularia; Unio; morphology; genetics; differences;
pp. 55 -

Unio mongolicus Middendorff, 1851 (Bivalvia: Unionidae) was described from Gorbitza mountain stream (in the east of Trans-Baikal Territory, Russia) and the taxonomy has changed over the past century and a half. A specimen of Middendorffinaia mongolica from the Gorbitza stream collected 160 years later is a match with the type illustration of Unio mongolicus from the type locality. Comparison of the shell morphology of the type specimen of U. mongolicus with the modern specimen collected from this location, combined with our analyses of molecular, anatomical and conchological data of M. cf. mongolica species from rivers of the Upper Amur River Basin and the far eastern Russia, revealed that these taxa all belong to a single polymorphic species. The molecular analysis of the COI gene fragment mtDNA of examined Comparatory Species assigned to Middendorffinaia Moskvicheva and Starobogatov, 1973 confirmed they are only intraspecific forms of M. mongolica. Morphological and genetic distances between M. mongolica and Nodularia douglasiae Griffith et Pidgeon, 1833 confirmed their assignment to two independent genera. Differences of morphologically similar species M. mongolica, N. douglasiae and Unio crassus Philipsson in Retzius, 1788 were separated based on conchological characteristics and anatomical features. History of the taxonomic changes for Unio mongolicus is discussed here.

Решение вопроса о таксономическом статусе вида Unio mongolicus Middendorff, 1851 (Bivalvia: Unionidae) из типового местонахождения в Забайкалье и история его таксономии
Клишко О.К.; Лопес-Лима М.; Фрауфе Е.; Боган А.Е.;
Leptochiton antarcticus; new records; Emperor Seamounts;
pp. 71 -

For the first time, the widely spread Antarctic species Leptochiton antarcticus was found at the Emperor Seamounts in the North Pacific Ocean. In spite of a large distance between the Emperor Seamounts and Antarctica, the found specimen have very similar shell, girdle, radula and gill features to the type material. I propose that L. antarcticus spread to the North Pacific from the Antarctic via a deep-water current near the ocean floor, and perhaps it inhabits the slopes of islands and continents from the South Ocean to the Emperor Seamounts.

Первая находка широко распространенного антарктического вида хитонов (Mollusca: Polyplacophora) в северной Пацифике
Сиренко Б.И.;
pp. 75 -

Two substitution names are proposed for primary homonyms introduced for land snail of the family Camaenidae in Thach [2018].

Исправление двух гомонимов и оригинального написания в книге Thach [2018]
Палл-Гергей Б.;
Metafruticicolini; phylogeny; systematics; mitochondrial DNA; nuclear DNA; Balkan Peninsula; Albania;
pp. 77 -

The genus-group taxon Elbasania Schileyko et Fehér, 2017 has recently been introduced as a subgenus of Metafruticicola Ihering, 1892 for a species occurring in north-western Greece and Albania. Using mitochondrial and nuclear markers, the phylogenetic relationships of Elbasania within Metafruticicolini (Hygromiidae) are reconstructed. The results of these analyses suggest that Elbasania is more closely related to Hiltrudia Nordsieck, 1993, which has a range adjacent to that of Elbasania from Croatia to northern Albania, than to Metafruticicola. Elbasania shares with Hiltrudia and also Cyrnotheba Germain, 1929 a very characteristic microsculpture of the shell and an overall similar genital system, which however differs among these three taxa with regard to its internal structures, especially those of the penis. Therefore, it is suggested regarding Elbasania as a distinct genus here.

К филогенетическим связям Elbasania Schi­leyko et Fehйr, 2017 (Pulmonata, Helicoidea, Hygromiidae)
Нaйбер М.Т.;