Type
Part
Number
1
Year
2017
Publication Date
Publication Type
Published online
Pages
pp. 51 -
58

Development of the larval and juvenile shells of the White Sea bivalve Zirfaea crispata has been studied. The main stages of shell development from D-stage to early juveniles were described. The formation of larval hinge, consisting of two small teeth on the left valve and two teeth of different size on the right valve was observed. The complex shape of the large tooth on the right valve was noted at the pre- metamorphosis stages. Development of a structure, typical for certain Pholadidae – an articular connection on the ventral edge of the shell was recorded. This connection consists of a rectangular tooth on the right valve and a depression, flanked by small projections, on the left valve. The ventral connection starts to form at the larval size of 300 µm and becomes fully formed prior to metamorphosis. After metamorphosis the ventral connection does not disappear, but continues to grow with the growing edge of dissoconch. The role and functional importance of this structure in Zirfaea is discussed.

DOI
10.35885/ruthenica.2017.27(1).5
Развитие личиночной и ювенильной раковины сверлящего двустворчатого моллюска Zirfaea crispata (Bivalva, Pholadidae) в Белом море
Флячинская Л.П.; Лезин П.А.;
Pages
pp. 39 -
49

 In accordance with the taxonomic system adopted in Russia and used also in Estonia, the largest local forms of pea clams (Sphaeriidae) have been treated as two species, P. amnicum and P. inflatum. The aim of the study was to clarify if P. amnicum and P. inflatum are separate species. Populations of both forms from Estonia were analysed genetically and morphologically. Analysis of the COI and ITS-1 gene fragments revealed that these two forms were genetically indistinguishable. Although there were statistically significant differences in the relative proportions of the shell between their typical individuals, there occurred also intermediate values. Consequently, P. inflatum cannot be considered as a separate species and should be treated as an ecological variety of P. amnicum that inhabits mainly a characteristic sandy substrate.

DOI
10.35885/ruthenica.2017.27(1).4
Таксономический статус Pisidium amnicum (Müller, 1774) и P. inflatum Megerle von Mühlfeld in Porro, 1838 (Mollusca: Bivalvia: Sphaeriidae)
Вооде М.;
Pages
pp. 31 -
37

On the Kugitangtau Ridge (western part of Pamiro-Alai mountain system) 16 specimens of a new species of molluscs referring to the nominative subfamily of the Bradybaenidae family have been found. The new taxon differs from all other species of this subfamily by total absence of all additional organs of female section of the reproductive tract (stylophore, additional sac, mucus glands, supraatrial bladder), bean- shaped short penis, and thick-walled penis sheath that attached at both proximal and distal ends. On the base of these characters the illustrated description of a new monotypic taxon Kugitangia hatagica Schileyko, Pa- zilov et Abdulazizova, gen. et sp. nov. is presented. Conchologically the new species does not differ reli- ably from Fruticicola fedtschenkoi and differs from Fruticicola perlucens mainly by the presence of fine granulation on the embryonic whorls.

 

DOI
10.35885/ruthenica.2017.27(1).3
Новый род семейства Bradybaenidae (Gastropoda, Pulmonata) из Центральной Азии
Шилейко А.; Пазылов А.; Абдулазизова Ш.;
Pages
pp. 15 -
30

Bela arctica A. Adams, 1855 has a complicated and confusing taxonomic history. Grant and Gale [1931] considered “Defrancia viridula Fabricius” Møller, 1842, Bela kobelti Verkrüzen, 1876, “Bela viridula Møller” G.O. Sars, 1878, and Lora tenuilirata cymata Dall, 1919 as its synonyms. It is demonstrated that Propebela arctica sensu Grant and Gale is a group of six species belonging to four genera. It is proposed to consider the following species as separate: Propebela arctica (A. Adams, 1855); Curtitoma finmarchia (Friele, 1886) comb. nov. [=“Defrancia viridula Fabricius” Møller, 1842]; Curtitoma georgossiani sp. nov. [=“Bela viridula Møller” G.O. Sars, 1878 (part)]; Granotoma kobelti (Verkrüzen, 1876) comb. nov., Granotoma tumida (Posselt, 1898) comb. nov. [=“Bela viridula Møller” G.O. Sars, 1878 (part)], and Obesotoma cymata (Dall, 1919). In addition, in this work for the first time Curtitoma livida comb. nov. is recorded from Russian waters.

DOI
10.35885/ruthenica.2017.27(1).2
Таксономическая головоломка: Propebela arctica (A. Adams, 1855) (Gastropoda, Mangeliidae) – шесть разных видов, объединяемых одним названием
Меркульев А.В.;
Pages
pp. 1 -
14

Three new species of the genus Stenosemus collected near Fiji and Solomon Islands of the central Pacific are described here. Stenosemus fijiensis sp. nov. from Fiji differs from the congeneric species by a unique sculpture of the central areas of tegmentum, consisting of triangular pits and light brown spots on valves. S. philippei sp. nov. and S. solomonensis sp. nov., both from the Solomon Islands, differ from other the species of the genus by having a head of major lateral tooth of radula bicuspidate with small outer denticle, shape and sculpture of dorsal spicules and sculpture of tegmentum.

DOI
10.35885/ruthenica.2017.27(1).1
Глубоководные хитоны рода Stenosemus (Mollusca: Polyplacophora) из Фиджи и Соломоновых островов
Сиренко Б.И.;