scholarly journals Biology and current state of anchovy kilka (Clupeonella engrauliformis Borodin)

2020 ◽  
Vol 2020 (2) ◽  
pp. 45-51
Author(s):  
Vjacheslav Petrovich Razinkov ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Yulia Nikolaevna Grozesku
Keyword(s):  
Survival Rate ◽  
Caspian Sea ◽  
Small Fish ◽  
Way Of Life ◽  
The Caspian Sea ◽  
Dynamics Of Abundance ◽  
Current State ◽  
Beroe Ovata ◽  
The Relationship ◽  
A New Species

In the Caspian Sea sprats is the name of the numerous small fish of herring family (Clupeonella). One of Clupeonella representatives is anchovy sprat. It differs from other types of kilka not only in appearance, but also in its way of life. A brief biology of the species and the state of ecosystem of the Caspian pelagic zone has been described. Anchovy kilka has been a leading targeted fish for over 50 years. Invading the Caspian Sea by ctenophore-mnemiopsis has undermined the stocks of anchovy sprats and caused the crisis of anchovy kilka fishing. Recently, there has been observed a slight increase in the number of the species. The survey materials confirm the increase in the number of juveniles in the studied catches. There are presented the materials from the last six years (2014–2019) of observations (eight research runs), shown the dynamics of abundance, biomass, spawning females, and total fertility of the population. Spawning efficiency and survival rate in early ontogenesis are analyzed. The relationship between kilka survival rate and the number of emerging generations is stated. Recommendations on restoring the stock of anchovy kilka are given. To restore the ecosystem of the Caspian Sea there has been proposed the invasion of a new species – ctenophore-beroe (Beroe ovata), which, due to the structure of its mouthparts eats only jelly-skinned (ctenophore-mnemiopsis, exceptionally) and can significantly reduce the number of ctenophore-mnemiopsis

TO STUDY THE BIOECOLOGY OF CASPIAN SHRIMPS

2021 ◽  
pp. 98-102
Author(s):  
Kais M. Guseynov ◽  
Aysha Sh. Gasanova ◽  
Marina V. Khlopkova
Keyword(s):  
Caspian Sea ◽  
Regression Equations ◽  
The Caspian Sea ◽  
Macrobrachium Nipponense ◽  
The North ◽  
Current State ◽  
Palaemon Elegans ◽  
Near Future ◽  
The Relationship ◽  
Shrimp Population

Only two species of shrimps live in the Caspian Sea: Palaemon elegans and P. adspersus (Crustacea, Decapoda: Palaemonidae), which were introduced to the Caspian Sea in 1931-1934 during the introduction of mullets. Data on the biology of these species of shrimps are reflected only in the works by E.N. Kudelina (1950) and M.P. Marochkina (1980). This determines the relevance of research on the current state of the Caspian shrimp population. The material was collected in various areas of the Middle Caspian Sea in the summer-autumn period. Both species live up to five meters deep. P. elegans prefer coastal underwater objects with dense thickets, P. adspersus - open shallow waters with sandy-muddy soil. To the north of Makhachkala, P. elegans predominates, to the south, the number of both species is the same, and to the east, P. adspersus dominates. The characteristics of breeding females are presented, and the dependence of fecundity on the length of egg-bearing females is revealed. The absolute fecundity increased with the increase in the size of the females. Regression equations reflecting the relationship between fecundity and length of egg-bearing females of P. elegans and P. adspersus are calculated, expressed by power equations, respectively: E = 0.044947 · L265356 and E = 2.323 · L17.4, where: E - fecundity, L-length. In October 2017, in May and October 2018, several specimens of the subtropical freshwater shrimp Macrobrachium nipponense were found downstream of the Terek River. Probably, in the near future, the species composition of the Caspian shrimp will be replenished with another species.

Verbascum shahsavarensis (Scrophulariaceae), a new species for Flora of Iran

Phytotaxa ◽  
2015 ◽  
Vol 203 (1) ◽  
pp. 76 ◽  
Author(s):  
Arash SOTOODEH ◽  
Laure Civeyrel ◽  
Farideh Attar
Keyword(s):  
New Species ◽  
Endemic Species ◽  
Caspian Sea ◽  
The Other ◽  
Distribution Map ◽  
Flora Of Iran ◽  
The Caspian Sea ◽  
Coastal City ◽  
North Of Iran ◽  
A New Species

A new endemic species, Verbascum shahsavarensis, is described from north of Iran. Based on two unique characters of this species, these being two anterior longitudinally obliquely inserted anthers and an ebracteolate pedicel, we compared it to species described by Murbeck in 1933. The new species can be easily distinguished from the other Iranian species by having bi-colored hairs on the stamen filaments and the unique anther and pedicel characters. A distribution map is provided. The name of new species comes from Shahsavar, the ancient name of Tonekabon, an old coastal city on the Caspian Sea.

scholarly journals ASSESSMENT OF INFLUENCE OF THE AUTOACCLIMATIZERS ON AUTOCHTHONOUS BIVALVE MOLLUSKS

2020 ◽  
pp. 6-11
Author(s):  
Marina Vladimirovna KHLOPKOVA ◽  
Ruslan Magomedovich BARKHALOV ◽  
Kais Magomedovich GUSEYNOV ◽  
Aysha Sharapatinovna GASANOVA
Keyword(s):  
Caspian Sea ◽  
Main Role ◽  
Bivalve Mollusks ◽  
The Caspian Sea ◽  
Anthropogenic Transformation ◽  
European Part Of Russia ◽  
Russian Sector ◽  
Mytilaster Lineatus ◽  
A New Species ◽  
Benthivorous Fishes

Anthropogenic transformation of the Caspian Sea biocenoses results in the loss of their uniqueness and decrease of their biodiversity. In recent years the main role in the formation of biomass has played the autoacclimatizant mollusks Abra ovata , Mytilaster lineatus and Cerastoderma glaucum which dominate the biocenoses of the Caspian sea and are the main food components of valuable commercial benthivorous fishes. In 2018 live specimens of Corbicula fluminalis (O. F. Muller, 1774), a new species of bivalve mollusks for the Russian sector of the Caspian sea and the entire European part of Russia, were first discovered on the Daghestan coast.

scholarly journals Contribution of the researchers of the Department of Ichthyology and Hydrobiology of Saint-Petersburg State University to the conservation of the Caspian sturgeon population

2019 ◽  
Vol 323 (4) ◽  
pp. 498-505
Author(s):  
R.P. Khodorevskaya
Keyword(s):  
Caspian Sea ◽  
Physiological State ◽  
Biological Indicators ◽  
Commercial Fishing ◽  
Caspian Basin ◽  
State University ◽  
The Caspian Sea ◽  
Saint Petersburg ◽  
Current State ◽  
Artificial Breeding

The paper deals with the main historical moments of the Caspian sturgeon population dynamics and the formation of their stocks. The participation of researchers of the Department of Ichthyology and Hydrobiology of Saint-Petersburg State University in creating the concept of sturgeon conservation in the Caspian Sea and the specialized institute of sturgeon farming in Astrakhan was highly appreciated. The materials on the contribution of the Department’s researchers to the study of the physiological state of sturgeon producers, improving their quality, survival and safety in the conditions of artificial breeding of these species are presented. The data on the reduction of the sturgeon abundance reared and released into the Caspian Sea by the Caspian littoral states are presented. A description of the current state of the sturgeon of the Caspian basin is given. The data on changes in stocks, the structure of the spawning part of the population and reproduction of the beluga, Russian sturgeon and stellate sturgeon in the Volga-Caspian basin under the conditions of the prohibition of their commercial fishing are analyzed. It was shown that during the years of the ban, the abundance and stocks of sturgeon and biological indicators of breeding migrants to spawn in the Volga continued to decrease and the proportion of females among them, which is associated with the illegal catch of sturgeon, comparable in scale to the commercial fishery before the ban was introduced. Reduced natural (up to its complete cessation in the Beluga) and artificial reproduction of sturgeons are stated. Only observing the moratorium on sturgeon fishing in all the Caspian littoral states, strengthening the protection of fish at feeding grounds and spawning migrations can preserve and restore their unique Caspian populations.

scholarly journals Retrospective analysis and current state of walleye stocks and fishery on the Dagestan coast of the Caspian Sea

2021 ◽  
Vol 699 (1) ◽  
pp. 012053
Author(s):  
A K Alieva ◽  
B M Nasibulina ◽  
T A Abdusamadov ◽  
T F Kurochkina ◽  
A D Guseynov
Keyword(s):  
Retrospective Analysis ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Current State

scholarly journals A new species of the genus Capoeta Valenciennes, 1842 from the Caspian Sea basin in Iran (Teleostei, Cyprinidae)

ZooKeys ◽  
2017 ◽  
Vol 682 ◽  
pp. 137-155 ◽  
Author(s):  
Arash Jouladeh Roudbar ◽  
Soheil Eagderi ◽  
Hamid Reza Ghanavi ◽  
Ignacio Doadrio
Keyword(s):  
New Species ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
A New Species

scholarly journals New data on the ctenophore Beroe ovata, an invader to the Caspian Sea

2022 ◽  
Vol 16 (4) ◽  
pp. 18-26
Author(s):  
S. V. Vostokov ◽  
A. S. Vostokova ◽  
E. N. Lobachev ◽  
Rahnama Haratbar Reza ◽  
Abtahi Behrooz ◽  
...  
Keyword(s):  
Caspian Sea ◽  
The Caspian Sea ◽  
Beroe Ovata

scholarly journals Current State and Economic Value of Astacofauna in Certain Areas of the Eastern Shelf of the Caspian Sea

2020 ◽  
Vol 15 (1) ◽  
pp. 28-36
Author(s):  
V. B. Ushivtsev ◽  
S. V. Vostokov ◽  
G. A. Akhmedova ◽  
M. L. Galaktionova ◽  
S. A. Kotenkov
Keyword(s):  
Comparative Analysis ◽  
Caspian Sea ◽  
Dominant Species ◽  
Economic Value ◽  
The Caspian Sea ◽  
Current State ◽  
Cluster Density ◽  
Eastern Shelf ◽  
Survey Protocol

Aim. The purpose of this work was to assess the current state of crayfish populations in their habitats on the eastern shelf of the Caspian Sea (Alexander Bekovich‐Cherkassky Bay).Material and Methods. Fieldwork was based on underwater research methods using light diving equipment. Collection of research material was carried out according to an established crayfish survey protocol using fixed grid sites of 100 square metres. Collected crayfish were identified by species, measured and weighed, fecundity of females and the condition of crayfish shells were recorded. Crayfish were then released back into the sea. Calculation of numbers was carried out on the basis of determination of cluster density (ind/m2) with a further assessment of useful biotype areas. Calculation of commercial stocks based on crayfish length. The research synthesized information derived from comparative analysis of modern research results and archival data from the 1970s to 1990s.Results. Analysis showed that significant changes in the composition of populations had occurred. The dominant species recorded was Caspiastacus pachypus Rathke which has substantially displaced from the biotopes Pontastacus eichwald  Воtt. which was previously the dominant species here.Conclusion. Comparative analysis of the modern state of the astacofauna on the eastern shelf and historical data indicates significant changes in the structure of populations of Caspian crayfish. The resilient C. pachypus has become the dominant species. Its small commercial size has significantly reduced the economic value of crayfish stocks. In general, however, commercial stocks of these crayfish make it possible to develop these marine biological resources.

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