scholarly journals Meiosis, embryonic, and larval development of the Black Sea scallop Flexopecten glaber ponticus (Bucquoy, Dautzenberg & Dollfus, 1889) (Bivalvia, Pectinidae)

2017 ◽  
Vol 2 (4) ◽  
pp. 50-57
Author(s):  
A. V. Pirkova ◽  
L. V. Ladygina
Keyword(s):  
Larval Development ◽  
Black Sea ◽  
Metaphase Plate ◽  
The Black Sea ◽  
Back Side ◽  
Sea Scallop ◽  
Metaphase Stage ◽  
Embryonic And Larval Development ◽  
Simultaneous Hermaphrodites ◽  
Larvae Development

The bivalve Flexopecten glaber ponticus is an endemic and extinguishing species of the Black Sea listed in Red book of Crimea. The sequence of meiosis stages following fertilization; embryonic and larval development of F. glaber ponticus were studied. The bivalve reproduces in June and July; these mollusks are simultaneous hermaphrodites. When spawning stimulated, fertilization of mature ova 54.7 ± 2.11 mkm in diameter take place at the first metaphase stage of meiosis. There were 12 bivalents with the sizes from 1.59 to 4.54 mkm on the metaphase plate. The duration of meiosis stage, embryonic and larvae development were determined. The structure of veliger provinculum was described. Right and left lock-valves consist of 4 teeth: two of them are on the front and back side on each valve. Measurements of larvae are presented. The description of shell and lock morphology will enable identification of F. glaber ponticus larvae at planktonic veliger stage. The data on duration of meiosis stage, embryonic and larvae development can be used in developing biotechnics of bivalve reproduction.

scholarly journals The Black Sea Flexopecten species-complex (Mollusca: Bivalvia: Pectinidae): Shell morphology and 16S rDNA variation

2020 ◽  
Vol 32 ◽  
pp. 10-18
Author(s):  
Yuriy V. Slynko ◽  
Elena E. Slynko ◽  
Sergey V. Schurov ◽  
Vitaliy I. Ryabushko
Keyword(s):  
Genetic Variability ◽  
16S Rdna ◽  
Black Sea ◽  
Taxonomic Status ◽  
Shell Morphology ◽  
The Black Sea ◽  
Theory Of Evolution ◽  
Sea Scallop ◽  
Rdna Variation ◽  
The Mediterranean

The taxonomic status and population variability of a Black Sea scallop (Flexopecten: Mollusca, Pectinidae) was evaluated in a DNA barcoding study using the 16S ribosomal DNA gene (=16S rDNA), in conjunction with seven morphological features of the shell. We conclude that the Black Sea form represents an eastern extension of the Mediterranean scallop F. glaber (Linnaeus, 1758). It is characterized by a significant lack of genetic variability when compared to the Mediterranean form, although it does contain new haplotypes not found in that species. There is also an increase in the mismatch in the distribution of nucleotides for the Black Sea form when compared with pooled samples of Mediterranean scallop. Plausible reasons for the observed phenomena are hypothesized from the standpoint of the epigenetic theory of evolution and the time since the scallop penetrated into the Black Sea. The lack of genetic variability is potentially due to founder effect and genetic drift.

MÖSSBAUER AND CHEMICAL ANALYSES OF SOME SEDIMENTS FROM THE ROMANIAN SHORE OF THE BLACK SEA

1979 ◽  
Vol 40 (C2) ◽  
pp. C2-445-C2-448
Author(s):  
D. Barb ◽  
L. Diamandescu ◽  
M. Morariu ◽  
I. I. Georgescu
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Chemical Analyses

Modeling of ecological conditions in the Euxine Basin in the Sarmatian and Maeotian by methods of diatom analysis

2019 ◽  
pp. 257-261
Author(s):  
Eleonora P. Radionova
Keyword(s):  
Black Sea ◽  
Late Miocene ◽  
The Black Sea ◽  
Subtidal Zone ◽  
Diatom Analysis ◽  
Diatom Flora ◽  
North West ◽  
Ecological Conditions ◽  
The North

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.

Subsatellite observations of the fundamental bio-optical parameters of the Black Sea (new approach)

2002 ◽  
Vol 8 (2-3) ◽  
pp. 231-238
Author(s):  
G.K. Korotaev ◽  
◽  
M.E. Li ◽  
G.A. Tolkachenko ◽  
◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Optical Parameters ◽  
New Approach

Significance of Mineralogical and Lithologic-Petrographical Rank in the Ranking of Geological Information

2020 ◽  
Vol 42 (4) ◽  
pp. 33-49
Author(s):  
O.V. CHEPIZHKO ◽  
V.V. YANKO ◽  
V.M. KADURIN ◽  
I.M. NAUMKO ◽  
S.M. SHATALIN
Keyword(s):  
Fluid Flow ◽  
Black Sea ◽  
Bottom Sediments ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Geochemical Characteristics ◽  
The Black Sea ◽  
Flow Parameters ◽  
Geochemical Parameters ◽  
Geological Information

For the first time the importance of mineralogical and lithological-petrographical ranks in the line of geological information ranks is substantiated for implementation of long-term forecasts, standard and non-standard approaches to research of physical and geochemical parameters as a basis of creation of complex system of forecast criteria and prospecting indicators of hydrocarbons within the sedimentary cover of Black sea based on the theory of global fluid-flows derivation. These criteria have different sensitivity to the object (hydrocarbon deposits) and are therefore ranked. The ranking determined the following parameters: 1) seismic data within the object, obtained by the method of deep seismic sounding, RWM SDP; 2) parameters of tectono-geodynamic structures; 3) the main characteristics of sedimentary cover and bedrock; 4) geochemical characteristics; 5) parameters of mineral complexes and fluid inclusions in mineral neoformations; 6) the value of the distribution of meiobenthos. Based on modern views of oil and gas geology, structural-tectonic and lithological-facies criteria are among the main ones. The study of the mineralogical component of sediments is made with using mineralogical, thermobarogeochemical and X-ray spectral methods. Fixation of anomalies of fluid flow at the bottom of the Black Sea as to the distribution of abiotic parameters in order to assess the prospects of oil and gas is determined by structural and tectonic features and high permeability of fluid flow; parameters of mineral complexes (minerals, facies) and genetic connections; heterogeneity of geochemical characteristics of bottom sediments; the presence of hydrocarbon inclusions in authigenic minerals of bottom sediments.

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