scholarly journals Black Sea turbot sperm motility depending on the dilution of seawater

2021 ◽  
Vol 937 (2) ◽  
pp. 022076
Author(s):  
Iu Baiandina
Keyword(s):  
Sperm Motility ◽  
Black Sea ◽  
Sperm Quality ◽  
Abiotic Factors ◽  
Reproductive Potential ◽  
The Black Sea ◽  
Energy Reserves ◽  
External Fertilization ◽  
Sperm Activation ◽  
Fertilizing Ability

Abstract The sperm motility of fish reflects their fertilizing ability. Sperm activation in fish with external fertilization occurs in an isotonic medium (sea or freshwater). The duration of sperm motility is a compromise between the level of energy reserves possessed by the sperm and the process of osmotic damage it experiences in the activating medium. Under natural conditions, various biotic and abiotic factors can affect the characteristics of motility. At the same time, when assessing the reproductive potential of males in laboratory conditions, the dilution and methods of its activation have a significant effect on the characteristics of sperm quality (namely, speed, the proportion of motile spermatozoa, and the time of their activity). In our work, we determined the main characteristics of the motility of the Black Sea turbot sperm at a dilution of 1:10 and 1: 100 with seawater. We have shown that, the average speed and percentage of motile sperm significantly decrease with higher dilution of seawater.

ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF

2017 ◽  
Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  
Keyword(s):  
Black Sea ◽  
Field Intensity ◽  
Deep Water ◽  
Coastal Waters ◽  
Integrated Management ◽  
Abiotic Factors ◽  
Environmental Safety ◽  
The Black Sea ◽  
Intensity Increase ◽  
First Time

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.

scholarly journals Colonization’s features of the Black Sea basin by recent invader Anadara kagoshimensis (Bivalvia: Arcidae)

2016 ◽  
Vol 1 (2) ◽  
pp. 3-17 ◽  
Author(s):  
N. K. Revkov
Keyword(s):  
Organic Matter ◽  
Black Sea ◽  
Reproductive Potential ◽  
Latency Period ◽  
Organic Pollution ◽  
The Black Sea ◽  
Hypoxic Conditions ◽  
Anadara Kagoshimensis ◽  
Quantitative Development ◽  
Mass Development

Lessepsian invader Anadara kagoshimensis is one of the important elements in the adaptive transformation of the Black sea shelf ecosystem in the second half of the XX century. The aim of the work is to analyse the Black Sea spatial and temporal colonization by this species according to the benthic database of Benthos Ecology Department of IMBR RAS (for the Crimean coasts) and literary sources for the whole Black Sea basin. The phases of this process are considered. A 10-year latency period followed after the first detection anadara in 1968 at Caucasian shelf. The main wave of anadara colonization in the Black Sea covered the Western and Eastern parts of the sea and fall within the period from second half of 1970s to 1980s. During that time period the extended development of A. kagoshimensis lead to forming own reproductive potential for next steps of expansion of this species to Anatolian and Crimean coasts in 1990s. About 20–25 years delay in detection of introduced species at the Northern and Southern parts of the Black Sea shelf, in presence at the Western and Eastern parts, could be an evidence of existing hydrological barrier between far distant nearshore areas of the Black Sea shelf. The reasons of the fluctuations in development of this species settlements are discussed. The phenomenon of introduction and mass development of A. kagoshimensis in the Black Sea during its the “most demand” period as a consumer of excess amount of organic matter, in conditions of eutrophication’s peak in the Black Sea basin at the end of 1980s – the beginning of 1990s is marked. Estuarine areas of the Black Sea shelf enriched by organic matter are the most favourable conditions for the mass development of this species. This quantitative rising is due to wide ecological plasticity and stress tolerance of A. kagoshimensis, which are determined by its physiological and biochemical adaptations to a hypoxic conditions often appearing during eutrophication. Based on parameters of abundance and biomass the actual implementation of A. kagoshimensis biotic potential in the Black Sea is revealed at least within Eastern and Western areas of the shelf, where peaks of its quantitative development is already passed in previous years. This conclusion for the Crimean sector is not obvious because of more recent invasion by anadara of this region. A decrease and stabilization of A. kagoshimensis development, with the exception of local zones near organic ”pollution” sources should be expected under maintaining the tendency of the basin deeutrophication.

scholarly journals Modern state of the reproductive potential of Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) (Pisces: Clupeidae) in Crimean region and conditions for its formation

2019 ◽  
Vol 4 (4) ◽  
pp. 3-14
Author(s):  
G. V. Zuyev
Keyword(s):  
Black Sea ◽  
Average Length ◽  
Reproductive Potential ◽  
Danube River ◽  
The Black Sea ◽  
Total Catch ◽  
Sprattus Sprattus ◽  
The Absolute ◽  
Individual Fecundity

Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) is one of the abundant species of fish in the Sea of Azov – Black Sea basin. Due to its large number sprat plays an extremely important role in the ecosystem of the sea, being an intermediate link between zooplankton and representatives of the highest trophic level – large predatory fish, dolphins, and birds. At the same time sprat is one of the important commercial fish in all the Black Sea countries, steadily being on the second place of catch volume in recent decades (after anchovy). The total catch reaches 100 thousand tons. Turkey and Ukraine are the main producing countries. Monitoring and forecast of biological state of sprat population with rising fishing intensity and climate changes are urgent tasks. The research subject of this article is the long-term (2000–2016) dynamics of biological (qualitative) parameters determining the population fecundity of Black Sea sprat in Crimean region, the current state of reproductive potential, and the conditions for its formation. The article is based on the results of own research. Parameters determining the population fecundity – the length-age structure of the spawning part population, the absolute individual fecundity, and the sex structure population (ratio between females and males) – were studied. In the long-term plan (in 2011–2016 compared with 2000–2004) the average length of spawning females decreased by 1.22 times (from 7.36 to 6.03 cm). It was accompanied by a decrease in the absolute individual fecundity by 2.39 times (from 13 625 to 5690 eggs). The numerical ratio between females and males decreased by 1.23 times (from 1.95 to 1.59). Simultaneously the sprat stock in the northern part of the Black Sea was reduced by more than 2.5 times (from > 500 thousand tons to < 200 thousand tons). As a result, the population fecundity of sprat in Crimean region decreased by more than 7 times (2.39 × 1.23 × 2.5). The conditions of sprat fishing in the northern part of the Black Sea (from the mouth of the Danube River to the Kerch Strait) were studied. They showed 2-fold decrease (from 251.9 thousand tons in 2000–2004 to 129.1 thousand tons in 2011–2016) in the total catch and more than 2.3-fold decrease (from 50.4 to 21.4 thousand tons) in average annual catch in this region. On the contrary, in the Crimean shelf the total catch at that time increased by 1.2 times (from 76.9 to 92.2 thousand tons), and its average annual value remained constant (15.4 thousand tons). While reducing the stock by 2.5 times, this means that the fishing pressure on the Crimean population increased 2.5 times. This fact suggests considering the factor of fishing as the main cause of its degradation. Validity of this version is confirmed by the fact of conjugacy (inverse connection) of interannual fluctuations between the catch and the length-age parameters of sprat in Crimean region in 2003–2013 previously found: catches over 15–16 thousand tons were accompanied by a next year decrease in the fish average length. Regulation of fishing is a necessary condition for preventing further degradation, for restoring and maintaining sustainable state of sprat population in Crimean region and its reproductive potential. The negative impact of natural (climatic and trophic) factors on the state of the population should be recognized as a secondary one. Local overfishing indicates indirectly the structuring of the commercial stock of Black Sea sprat, its division into a number of geographical aggregations (stock units), i. e. the presence of intraspecific differentiation.

Meiobenthos as indicator of gaseous hydrocarbons reservoirs existing under the seabed of the Black Sea

2021 ◽  
Author(s):  
Valentina Yanko ◽  
Anna Kravchuk ◽  
Irina Kulakova ◽  
Tatiana Kondariuk
Keyword(s):  
Black Sea ◽  
Abiotic Factors ◽  
Taxonomic Composition ◽  
The Black Sea ◽  
Northwestern Part ◽  
Hydrocarbon Gases ◽  
The Sustainable Development ◽  
Dual Analysis ◽  
Gaseous Hydrocarbons ◽  
Physical And Chemical

&lt;p&gt;This &lt;span&gt;presentation&lt;/span&gt; represents a case study that reviews research into the relationship between meiobenthos distribution and concentrations of hydrocarbon gases (HG), primarily methane, in the sediments of the northwestern part of the Black Sea, including gases released by mud volcanoes and gas seeps. Evidence forming the basis of this research comes from meiobenthos here represented by 29 species of benthic foraminifers, 7 species of ostracods, and 44 species of nematodes. The potential use of these meiobenthic organisms as indicators of gaseous hydrocarbons reservoirs existing under the seabed is evaluated according to two linked axes, namely the dual analysis of abiotic factors (physical and chemical parameters of the water column, gasmetrical, geochemical, lithological, and mineralogical properties of the sediments) and biotic characteristics (quantitative and taxonomic composition of foraminifers, nematodes, and ostracods). Studies of this kind have been directed toward developing interdisciplinary methods to improve the search for HG accumulations, especially methane, under the seabed. Development of such methods might have substantial socio-economic importance for the economy of Ukraine as well as that of other Black Sea countries, and such methods might also contribute to the sustainable development of Black Sea ecosystems.&lt;/p&gt;

Fish Stock Indicators as Measure for Sustainability

2015 ◽  
pp. 118-182 ◽  
Author(s):  
Violin S. Raykov ◽  
Ivelina Zlateva
Keyword(s):  
Black Sea ◽  
Fishery Management ◽  
Management Strategies ◽  
Age Determination ◽  
Reproductive Potential ◽  
Local Environment ◽  
Point Of View ◽  
The Black Sea ◽  
Fish Stock ◽  
Mortality Estimation

Particular species may be good indicators of specific environmental factors in their local environment. It was found that one of the main objectives for effective and sustainable management of the fish stocks is to make regular annual assessment of the parental stock biomass, length and weight growth, age determination, mortality estimation and reproductive potential estimation. The Black Sea sprat (Sprattus sprattus L.) is a key species in the Black Sea ecosystem. Small pelagic forage fish and especially local one with shared stocks are very important from ecological (key trophic level) and commercial (intensively exploited) point of view. Fishery management strategies must ensure that fishing mortality will not exceed that which corresponds to MSY, and that the biomass will not fall below a predefined threshold. The goal of the chapter is to define the main objectives and measures for sustainable sprat exploitation in order to be in favour of decision makers and fishery managers.

scholarly journals Gelatinous macroplankton of the open pelagial and shelf of the Black Sea: Distribution in autumn 2016 and interannual changes in biomass and abundance

2019 ◽  
Vol 4 (3) ◽  
pp. 3-14 ◽  
Author(s):  
B. E. Anninsky ◽  
S. M. Ignatyev ◽  
G. A. Finenko ◽  
N. A. Datsyk
Keyword(s):  
Black Sea ◽  
Oxygen Sensor ◽  
Abiotic Factors ◽  
Lower Boundary ◽  
Somatic Growth ◽  
Sea Surface ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Trophic Relations ◽  
Order Of Magnitude

The gelatinous macroplankton community of the Black Sea renews annually and functionates differently depending on the complicated system of trophic relations and interannual fluctuations of biotic and abiotic factors. Its monitoring is necessary for the evaluation of the current state and possible vectors of evolution of the whole pelagic ecosystem. For this purpose the data on the composition and distribution of gelatinous organisms were collected on the 89th cruise of the RV “Professor Vodyanitsky” (September – October of 2016) at 62 stations located in coastal areas and in the open sea to the south and southwest of Crimea. Samples were taken with the Bogorov – Rass net (inlet area of 0.5 m², mesh of 300 µm) using vertical net hauls from the bottom to the sea surface in the shallow shelf and from the lower boundary of the oxygen zone [according to the dissolved oxygen sensor CTD SBE plus (Sea Bird)] to the sea surface – in deepwater areas. Aurelia aurita and 3 ctenophore species (Mnemiopsis leidyi, Pleurobrachia pileus, and Beroe ovata) were present together in the 90 % of the samples (on 56 stations). In spite of some increase in average biomass of every species in deep sea areas, and, particularly, of A. aurita up to 260 g per m², there was no difference between the data of 2016 and 2010 (p > 0.05). The abundance of A. aurita increased by about one order of magnitude (p < 0.001); the abundance of P. pileus increased 2–5 times (p < 0.001); of B. ovata – 3–15 times (p < 0.01). M. leidyi abundance increased only at the outer Black Sea shelf; in other regions it could have been restricted by B. ovata predation. A. aurita linear specific growth rate in 2016 was one of the lowest for the last 15 years. Slow somatic growth of the jellyfish indicates unfavorable conditions for this species in 2016. However, the jellyfish biomass was higher than that of previous years because of the huge abundance of the spring generation. The weakening competition with planktivorous ctenophores may lead to even greater increase in the ecological valence of A. aurita among other gelatinous predators in the nearest future.

scholarly journals DYNAMICS OF THE NUMBER OF THE STEPPER SNAKE VIPERA RENARDI IN THE SOUTH OF THE LEFT BANK OF UKRAINE

2021 ◽  
pp. 63-72
Author(s):  
Selyunina Z. V. ◽  
Markautsan О. Е. ◽  
Dubov S. V.
Keyword(s):  
Protected Areas ◽  
Black Sea ◽  
Abiotic Factors ◽  
Local Population ◽  
Biosphere Reserve ◽  
Irrigated Agriculture ◽  
The Black Sea ◽  
Forest Steppe ◽  
Left Bank ◽  
The South

The steppe viper (Vipera renardi (= ursinii) Christoph, 1861) is a background species of snakes in the steppe zone of southern left-bank Ukraine. This species is a figurant in the Red Book of Ukraine and is protected in accordance with the Bern Convention. According to the IUCN Red List, Vipera renardi has a Vulnerable species (VU) status, which is assigned to species that are under threat of becoming endangered. Anthropogenic transformation, namely, plowing, afforestation, irrigated agriculture, fires, synanthropization, etc., lead to the fact that in the Black Sea steppe, in the Lower Dnieper arenas of steppe, the viper disappears. This species has been preserved in the protected areas of the region and in the less transformed areas of the coastal and sandy steppe. The study area includes the forest-steppe areas of the Black Sea Biosphere Reserve (BSBR) and the territory of the “Svyatoslav’s Biloberezhzhya” National Nature Park (NNP BS) on the Kinburn Peninsula, the Black Sea areas and the islands of Tendrivska and Yahorlytska Bays, which are part of the Black Sea Biosphere Reserve. The dynamics of the number of steppe vipers also depends on abiotic factors too. In wetter years and the next 1-2 years, the number of vipers in the region decreases. In dry years, the number of steppe vipers increases. In the last 20 years, according to the results of long-term monitoring, the dynamics of the steppe viper population has a negative trend both in the Black Sea steppe and in the arenas of the Lower Dnieper.The cyclic dynamics of the steppe viper in our region is 3-5 years, the highest amplitude is 1.4 units, the maximum values of the relative abundance over the past 20 years have decreased from 1.5 to 0.4 ind./km, the minimum - from 0.3 to 0,1 ind./km. To preserve the population of this species in the south of the left-bank Ukraine, it is necessary to increase the areas with limited use of natural resources, namely, with the prohibition of plowing, prevention of excessive grazing and exploitation of sand deposits. In addition, it is required to strengthen environmental education and propaganda among the local population about the need to preserve the steppe viper in natural conditions and change the hypertrophied thought about the danger of this snake. The extensive network of protected areas in the region: reserves, national nature parks, regional landscape parks, protected tracts, etc., contributes to the conservation of this species. Key words: steppe viper, Black Sea steppe, Lower Dnieper arenas, population dynamics, monitoring.

Effect of phytoplankton adaptation on the distribution of its biomass and chlorophyll a concentration in the surface layer of the Black Sea

2019 ◽  
Vol 48 (4) ◽  
pp. 404-414 ◽  
Author(s):  
Liudmila Stelmakh ◽  
Tatiana Gorbunova
Keyword(s):  
Surface Layer ◽  
Spatial Variability ◽  
Black Sea ◽  
Phytoplankton Biomass ◽  
Abiotic Factors ◽  
Nitrogen Concentration ◽  
The Black Sea ◽  
Total Phytoplankton ◽  
Upper Mixed Layer ◽  
Effect Of Light

Abstract Using the field data collected in the Black Sea in September 2005–May 2013, the authors studied the spatial variability of the ratio of organic carbon to chlorophyll a (C:Chl a) in the sea surface layer (0–1 m). The C:Chl a ratio is an important parameter that reflects the phytoplankton adaptation to abiotic factors. Its maximum variations occurred in September–October 2005 and October 2010 when the highest spatial variability of average light intensity and nitrogen concentration was observed in the upper mixed layer. As a result, the maps of phytoplankton biomass differed from chlorophyll maps. In August 2011, no effect of light or nitrogen on the spatial variability of the C:Chl a ratio was found. Changes in the contribution of dinoflagellates to the total phytoplankton biomass affected the C:Chl a ratio variability, which was two times lower compared to September–October 2005 and October 2010. Also, the spatial distribution of phytoplankton biomass differed from the distribution of chlorophyll a concentration only in some areas of the sea. In May 2013, environmental factors slightly varied across the study area and the spatial variability of the C:Chl a ratio was insignificant. Therefore, the map of phytoplankton biomass indicated similarities with the chlorophyll map.

scholarly journals Subordinate male cichlids retain reproductive competence during social suppression

2011 ◽  
Vol 279 (1728) ◽  
pp. 434-443 ◽  
Author(s):  
Jacqueline M. Kustan ◽  
Karen P. Maruska ◽  
Russell D. Fernald
Keyword(s):  
Social Status ◽  
Sperm Motility ◽  
Sperm Quality ◽  
Reproductive Potential ◽  
Testis Size ◽  
Reproductive Suppression ◽  
Tightly Coupled ◽  
Astatotilapia Burtoni ◽  
Save Energy ◽  
Social Suppression

Subordinate males, which are excluded from reproduction often save energy by reducing their investment in sperm production. However, if their position in a dominance hierarchy changes suddenly they should also rapidly attain fertilization capability. Here, we asked how social suppression and ascension to dominance influences sperm quality, spermatogenesis and reproductive competence in the cichlid Astatotilapia burtoni , where reproduction is tightly coupled to social status. Dominant territorial (T) males are reproductively active while subordinate non-territorial (NT) males are suppressed, but given the opportunity, NT males will perform dominance behaviours within minutes and attain T male testes size within days. Using the thymidine analogue 5-bromo-2-deoxyuridine (BrdU) to label germ cell proliferation, we found that the spermatogenic cycle takes approximately 11–12 days, and social status had no effect on proliferation, suggesting that spermatogenesis continues during reproductive suppression. Although sperm velocity did not differ among social states, NT males had reduced sperm motility. Remarkably, males ascending in status showed sperm motility equivalent to T males within 24 h. Males also successfully reproduced within hours of social opportunity, despite four to five weeks of suppression and reduced testis size. Our data suggest that NT males maintain reproductive potential during suppression possibly as a strategy to rapidly improve reproductive fitness upon social opportunity.

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