Caspian Sea (caspian + sea)

Distribution by Scientific Domains


Selected Abstracts


LIPID, CHOLESTEROL AND FATTY ACID PROFILE OF SOME COMMERCIALLY IMPORTANT FISH SPECIES FROM SOUTH CASPIAN SEA

JOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2010
S. PIRESTANI
ABSTRACT The fatty acid, lipid, cholesterol and energy contents in five commercially important fish species from South Caspian Sea (common kilka, Caspian kutum, golden gray mullet, common carp and pike perch) were evaluated. The fatty acid compositions of these five fish species ranged from 28.99 to 41.05% saturated fatty acids, 40.99,56.25% monounsaturated fatty acids and 14.22,23.03% polyunsaturated fatty acids. Among these, those occurring in the highest proportions were palmitic acid (20.42,27.9%), palmitoleic acid (11.09,26.26%), oleic acid (16.1,36.94%), eicosapentaenoic acid (3.22,7.53%) and docosahexaenoic acid (3.86,11.36%). The lipid, cholesterol and energy contents ranged from 1.97% to 10.23%, 57,302 mg/100 g and 4365.4,5544.2 cal g/dm, respectively. The obtained Statistical results showed that in these fishes, many of the above mentioned indices had significant differences (P , 0.01) and the cluster analysis results of fatty acid compositions showed that common carp and pike perch had good similarity, followed by the Caspian kutum and golden gray mullet. However, common kilka did not show any similarity to others. PRACTICAL APPLICATIONS Fish consumption has been linked to health benefits such as reduced risk of coronary heart disease. This is largely attributed to the lipid, cholesterol, energy contents, fatty acid compositions and the polyunsaturated fatty acids present in fish oils. The ,-3 : ,-6, polyunsaturated fatty acid/saturated fatty acid and eicosapentaenoic acid + docosahexaenoic acid/C16 ratios are considered to be useful criteria for comparing relative nutritional and oxidation values of fish oils. [source]


Restoration of sturgeons: lessons from the Caspian Sea Sturgeon Ranching Programme

FISH AND FISHERIES, Issue 3 2000
D.H. Secor
Depletion of sturgeon stocks world-wide has increased interest in aquaculture-based restoration programmes. The Caspian Sea Sturgeon Ranching Programme (SRP) of the former Soviet Union represents a unique opportunity to evaluate expense, benefits and potential ecological and genetic effects of such restoration programmes. The SRP was initiated in the 1950s to compensate for lost spawning habitat in the Volga River and elsewhere. After its completion in 1962, the Volgograd Dam reduced spawning grounds in the Volga River system, the principal spawning tributary of the Caspian Sea, by ,80%. For two of the three commercial sturgeon species (Russian sturgeon, Acipenser güldenstädti, and stellate sturgeon, A. stellatus), yields improved after the imposition of the 1962 moratorium on sturgeon harvests in the Caspian Sea. Volga River fisheries were managed for spawning escapement. Although imprecisely known, the contribution of the millions of stocked Russian and stellate juveniles during 1962,91 was most likely important to sustaining fisheries, although less so (contributing to <30% of the adult stock) than natural recruitment. Apparently, reduced spawning grounds, supplemented with artificial spawning reefs were sufficient to support reproduction and large fishery yields of Russian and stellate sturgeons. For beluga sturgeon, Huso huso, harvests in the Volga River were nearly all dependent upon hatchery stocking. Beluga sturgeon spawning grounds were mostly eliminated with the construction of the Volgograd Dam. Without the hatchery programme, beluga sturgeon in the Volga River and Caspian Sea would in all likelihood have been extirpated. Currently, sturgeons are severely depleted in the Volga River and Caspian Sea due to poaching and lack of co-operation between countries exploiting the species. Aquaculture-based restoration in Russia is now viewed a chief means of rebuilding stocks of Caspian Sea sturgeons. [source]


Tagging and tracking juvenile sturgeons in shallow waters of the Caspian Sea (less than 10 m depth) using CWT (Coded Wire Tags) and barbel incision

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2006
B. Fadaee
First page of article [source]


Initial investigation on liver oil extraction from three sturgeon species of the Caspian Sea

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2006
Ayoub Yousefi Jourdehi
No abstract is available for this article. [source]


Intraspecific structure within three caviar-producing sturgeons (Acipenser gueldenstaedtii, A. stellatus, and Huso huso) based on mitochondrial DNA analysis

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2005
P. Doukakis
Summary A survey of three mitochondrial DNA regions (control region, NADH5, cytochrome b) and comprehensive sequencing of the control region (631,646 bps) was conducted to examine whether subspecies and geographic populations within three species of Eurasian sturgeons, Acipenser gueldenstaedtii, A. stellatus, and Huso huso, are genetically distinct. Neither subspecies nor populations exhibited diagnostic distinction or reciprocal monophyly in any gene region examined. For the control region, molecular variance analyses (amova) indicate that most of the variance is because of differences among haplotypes within subspecies (H. huso: 99.6%; A. stellatus: 95.0%; A. gueldenstaedtii: 81.0%) and populations (A. gueldenstaedtii: 76.1%). Significant pairwise F -values were found for all pairwise comparisons except for Sea of Azov and Caspian Sea A. gueldenstaedtii and Caspian Sea and Black Sea A. stellatus and H. huso. Only weak genetic differentiation is apparent between select subspecies and populations, reflective of biogeographic and management history. High genetic diversity within A. gueldenstaedtii suggests the possibility of additional population structure. Future research and management projects should consider these results. [source]


Glacial refugia for summer-green trees in Europe and south-west Asia as proposed by ECHAM3 time-slice atmospheric model simulations

JOURNAL OF BIOGEOGRAPHY, Issue 12 2007
Suzanne A. G. Leroy
Abstract Aim, To generate maps of potential refugia for summer-green trees during the Last Glacial Maximum (LGM). Locations, Southern Europe and south-western Asia. Methods, Time-slice simulations of the atmospheric climate with the ECHAM3 model are used for the LGM. Limiting factors beyond which cool and warm groups of deciduous trees cannot grow (such as temperature in growing degree days, minimum monthly temperature and precipitation in summer) are chosen. A limited validation by fossil pollen and charcoal records from LGM sites was done. Results, Two sets of maps extending from Europe to the Caspian region for cool and warm summer-green trees are presented. Three criteria are combined using contour lines to indicate confidence levels. Small areas within the three southern peninsulas of Europe (Spain, Italy and Greece) are highlighted as possible refugia for summer-green trees. Further, areas that have remained poorly known are now proposed as refugia, including the Sakarya,Kerempe region in northern Turkey, the east coast of the Black Sea and the area south of the Caspian Sea. Main conclusions, The maps produced in this study could be used to facilitate better long-term management for the protection of European and south-western Asian biodiversity. [source]


LIPID, CHOLESTEROL AND FATTY ACID PROFILE OF SOME COMMERCIALLY IMPORTANT FISH SPECIES FROM SOUTH CASPIAN SEA

JOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2010
S. PIRESTANI
ABSTRACT The fatty acid, lipid, cholesterol and energy contents in five commercially important fish species from South Caspian Sea (common kilka, Caspian kutum, golden gray mullet, common carp and pike perch) were evaluated. The fatty acid compositions of these five fish species ranged from 28.99 to 41.05% saturated fatty acids, 40.99,56.25% monounsaturated fatty acids and 14.22,23.03% polyunsaturated fatty acids. Among these, those occurring in the highest proportions were palmitic acid (20.42,27.9%), palmitoleic acid (11.09,26.26%), oleic acid (16.1,36.94%), eicosapentaenoic acid (3.22,7.53%) and docosahexaenoic acid (3.86,11.36%). The lipid, cholesterol and energy contents ranged from 1.97% to 10.23%, 57,302 mg/100 g and 4365.4,5544.2 cal g/dm, respectively. The obtained Statistical results showed that in these fishes, many of the above mentioned indices had significant differences (P , 0.01) and the cluster analysis results of fatty acid compositions showed that common carp and pike perch had good similarity, followed by the Caspian kutum and golden gray mullet. However, common kilka did not show any similarity to others. PRACTICAL APPLICATIONS Fish consumption has been linked to health benefits such as reduced risk of coronary heart disease. This is largely attributed to the lipid, cholesterol, energy contents, fatty acid compositions and the polyunsaturated fatty acids present in fish oils. The ,-3 : ,-6, polyunsaturated fatty acid/saturated fatty acid and eicosapentaenoic acid + docosahexaenoic acid/C16 ratios are considered to be useful criteria for comparing relative nutritional and oxidation values of fish oils. [source]


The past, present, and future Aral Sea

LAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2010
Philip Micklin
Abstract The Aral Sea, a once vast brackish terminal lake in the heart of Central Asia, has been rapidly drying since the 1960s. It had separated into four separate waterbodies by September 2009. The maximum water level decline was more than 26 m, whereas the lake surface area decreased 88% and the water volume 92%. The lake salinity increased by more than 20-fold. Prior to the modern recession, the Aral Sea experienced a number of water level declines and subsequent recoveries over the last 10 millennia. The main causative factor until the 1960s was the periodic westward diversion of the Amu Dar'ya, the main influent river, towards the Caspian Sea by both natural and human forces. The post-1960 recession, however, was overwhelmingly the result of unsustainable irrigation development. The lake's modern recession has caused a broad range of severe negative ecological, economic and human welfare problems. To restore the Aral Sea to its 1960s' size and ecological condition would be very difficult, if not impossible, in the foreseeable future. The plight of the Aral Sea, however, is far from hopeless. Partial restoration of portions of the lake is still feasible. A project to raise the Small (northern) Sea was completed in Fall 2005, raising its water level by 2 m, and lowering its salinity to a level not much higher than the early 1960 levels. Its ecological recovery has been dramatic, and a new project to improve further the Small Aral was recently announced. Improving the Large (southern) lake would be much more difficult and expensive. A project to save the deep Western Basin partially is technically feasible, however, and should be given careful evaluation. It is important to repair and preserve what is left of the deltas of the two tributary rivers, Syr Dar'ya and Amu Dar'ya, as these two rivers are of great ecological and economic value, and act as biological refugia for endemic species of the Aral Sea. [source]


Impact of a new invasive ctenophore (Mnemiopsis leidyi) on the zooplankton community of the Southern Caspian sea

MARINE ECOLOGY, Issue 4 2008
Abolghasem Roohi
Abstract The invasive ctenophore Mnemiopsis leidyi (Agassiz), which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001,2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (four Copepoda and one Cladocera) species were identified. The total number of zooplankton species found here was 50% less than in a previous investigation performed in the same region in 1996 before the introduction of Mnemiopsis leidyi into the Caspian Sea. Cladocera species seemed to be highly affected by the invasion of Mnemiopsis leidyi; only one species, Podon polyphemoides, remained in the study area, whereas 24 Cladocera species were found in the study carried out in 1996. Whereas among the Copepoda Eurytemora minor, Eurytemora grimmi, Calanipeda aquae dulcis and Acartia tonsa that were abundant before the Mnemiopsis leidyi invasion, only A. tonsa (copepodites and adults) dominated the inshore and offshore waters after the invasion. The maximum in zooplankton abundance (22,088 ± 24,840 ind·m,3) and biomass (64.1 ± 56.8 mg·m,3) were recorded in December 2001 and August 2004, respectively. The annual mean zooplankton abundance during 2001,2006 was in the range of 3361,8940 ind·m,3; this was two- to five-fold less than the zooplankton abundance in 1996. During 2001,2006, the highest abundance and biomass of Mnemiopsis leidyi were observed during summer-autumn months coincident with warm temperatures and generally when the abundance of other zooplankton organisms was low. [source]


Divergence with gene flow between Ponto-Caspian refugia in an anadromous cyprinid Rutilus frisii revealed by multiple gene phylogeography

MOLECULAR ECOLOGY, Issue 4 2008
PETR KOTLÍK
Abstract The Black and Caspian Seas have experienced alternating periods of isolation and interconnection over many Milankovitch climate oscillations and most recently became separated when the meltwater overflow from the Caspian Sea ceased at the end of the last glaciation. Climate-induced habitat changes have indisputably had profound impacts on distribution and demography of aquatic species, yet uncertainties remain about the relative roles of isolation and dispersal in the response of species shared between the Black and Caspian Sea basins. We examined these issues using phylogeographical analysis of an anadromous cyprinid fish Rutilus frisii. Bayesian coalescence analyses of sequence variation at two nuclear and one mitochondrial genes suggest that the Black and Caspian Seas supported separate populations of R. frisii during the last glaciation. Parameter estimates from the fitted isolation-with-migration model showed that their separation was not complete, however, and that the two populations continued to exchange genes in both directions. These analyses also suggested that majority of migrations occurred during the Pleistocene, showing that the variation shared between the Black and Caspian Seas is the result of ancient dispersal along the temporary natural connections between the basins, rather than of incomplete lineage sorting or recent human-mediated dispersal. Gene flow between the refugial populations was therefore an important source of genetic variation, and we suggest that it facilitated the evolutionary response of the populations to changing climate. [source]


Comparative phylogeography of Ponto-Caspian mysid crustaceans: isolation and exchange among dynamic inland sea basins

MOLECULAR ECOLOGY, Issue 10 2006
ASTA AUDZIJONYTE
Abstract The distributions of many endemic Ponto-Caspian brackish-water taxa are subdivided among the Black, Azov and Caspian Sea basins and further among river estuaries. Of the two alternative views to explain the distributions, the relict school has claimed Tertiary fragmentation of the once contiguous range by emerging geographical and salinity barriers, whereas the immigration view has suggested recolonization of the westerly populations from the Caspian Sea after extirpation during Late Pleistocene environmental perturbations. A study of mitochondrial (COI) phylogeography of seven mysid crustacean taxa from the genera Limnomysis and Paramysis showed that both scenarios can be valid for different species. Four taxa had distinct lineages related to the major basin subdivision, but the lineage distributions and depths of divergence were not concordant. The data do not support a hypothesis of Late Miocene (10,5 Myr) vicariance; rather, range subdivisions and dispersal from and to the Caspian Sea seem to have occurred at different times throughout the Pleistocene. For example, in Paramysis lacustris each basin had an endemic clade 2,5% diverged from the others, whereas Paramysis kessleri from the southern Caspian and the western Black Sea were nearly identical. Species-specific ecological characteristics such as vagility and salinity tolerance seem to have played important roles in shaping the phylogeographic patterns. The mitochondrial data also suggested recent, human-mediated cryptic invasions of P. lacustris and Limnomysis benedeni from the Caspian to the Sea of Azov basin via the Volga-Don canal. Cryptic species-level subdivisions were recorded in populations attributed to Paramysis baeri, and possibly in P. lacustris. [source]


On the Structure of the Adrenal Gland of the Common Seal (Phoca vitulina vitulina)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2004
H. Bragulla
Summary The adrenal gland is a vitally important endocrine gland that occupies a central role in the regulatory mechanisms of the body metabolism. Environmental stress factors lead to permanent strain and overload of the body resulting in structural alterations of the adrenals that in turn are followed by hormonal imbalances. This leads to an increased susceptibility to bacterial and viral diseases. The recurrence of numerous fatalities in the different seal populations of the North Sea (during the years 1988, 1989 and 2002), of the Baikal Lake and Caspian Sea (during the years 2000 and 2001) were the motive for a morphological investigation of the species-specific structure of the adrenal gland of the common seal in order to differentiate environmental stress-induced pathological alterations from the physiological structure of this organ. The study was based on adrenals of 112 common seals (Phoca vitulina vitulina) using light microscopic and transmission and scanning electron microscopic methods. The phocine adrenal gland displays several structural characteristics. Originating from the connective tissue organ capsule, narrow and broad septa intersperse the adrenal cortex. These septa contain blastemata as a reserve for the regeneration of hormone-producing cortical cells. Such blastemata are also occurring in the form of an intermediate zone in between the zona glomerulosa and zona fasciculata in the phocine adrenal cortex. Another species-specific characteristic is an inverse part of the adrenal cortex encircling the central vein of the organ. These structural features have to be considered in assessment and definition of pathological alterations of the adrenals as observed in the form of exhausted blastema cell pools in the adrenocortex of seals perished in the mentioned phocine mass mortalities. [source]


The effect of maternal size on larval characteristics of Persian sturgeon Acipenser persicus

AQUACULTURE RESEARCH, Issue 9 2009
Rajab Mohammad Nazari
Abstract The objective of this work was to study the relationship between female size (weight) and variables of egg and larval stage of Persian sturgeon Acipenser persicus. In this study, 19 female breeders were captured in Caspian Sea and fertilized by routine methods. Positive significant correlations (P<0.05) were established between female weight and ovulated eggs per female, time of second mitosis division and volume of yolk-sac at hatching. There was not significant correlation (r=0.33, P=0.161) between female weight and egg diameter. Female weight was not affected weight of larvae at hatching time (r=0.37, P=0.119), as well as larval length (r=,0.14, P=0.558) and larval weight at the end of the experiment (48 hours after first feeding) (r=0.16, P=0.491). Mortality rate during yolk-sac absorption was higher with increased female weight but their correlation was not significant (r=0.40, P=0.076). During the first feeding stage, mortality rate was 13.39% and there was no significant correlation between mortality rate in this period and female weight (r=,0.12, P=0.613). Conclusively, as a result female size influenced fecundity, time of second mitosis division and yolk-sac volume at hatching time without affecting mortality rate during yolk-sac absorption and first feeding stage in Persian sturgeon. Thus, smaller female broods do not cause more mortality than larger ones in larval production and they can be used in reproduction procedure. [source]


Phylogeny of Mysis (Crustacea, Mysida): history of continental invasions inferred from molecular and morphological data

CLADISTICS, Issue 6 2005
Asta Audzijonyt
We studied the phylogenetic history of opossum shrimps of the genus Mysis Latreille, 1802 (Crustacea: Mysida) using parsimony analyses of morphological characters, DNA sequence data from mitochondrial (16S, COI and CytB) and nuclear genes (ITS2, 18S), and eight allozyme loci. With these data we aimed to resolve a long-debated question of the origin of the non-marine (continental) taxa in the genus, i.e., "glacial relicts" in circumpolar postglacial lakes and "arctic immigrants" in the Caspian Sea. A simultaneous analysis of the data sets gave a single tree supporting monophyly of all continental species, as well as monophyly of the taxa from circumpolar lakes and from the Caspian Sea. A clade of three circumarctic marine species was sister group to the continental taxa, whereas Atlantic species had more distant relationships to the others. Small molecular differentiation among the morphologically diverse endemic species from the Caspian Sea suggested their recent speciation, while the phenotypically more uniform "glacial relict" species from circumpolar lakes (Mysis relicta group) showed deep molecular divergences. For the length-variable ITS2 region both direct optimization and a priori alignment procedures gave similar topologies, although the former approach provided a better overall resolution. In terms of partitioned Bremer support (PBS), mitochondrial protein coding genes provided the largest contribution (83%) to the total tree resolution. This estimate however, appears to be partly spurious, due to the concerted inheritance of mitochondrial characters and probable cases of introgression or ancestral polymorphism. © The Willi Hennig Society 2005. [source]


Divergence with gene flow between Ponto-Caspian refugia in an anadromous cyprinid Rutilus frisii revealed by multiple gene phylogeography

MOLECULAR ECOLOGY, Issue 4 2008
PETR KOTLÍK
Abstract The Black and Caspian Seas have experienced alternating periods of isolation and interconnection over many Milankovitch climate oscillations and most recently became separated when the meltwater overflow from the Caspian Sea ceased at the end of the last glaciation. Climate-induced habitat changes have indisputably had profound impacts on distribution and demography of aquatic species, yet uncertainties remain about the relative roles of isolation and dispersal in the response of species shared between the Black and Caspian Sea basins. We examined these issues using phylogeographical analysis of an anadromous cyprinid fish Rutilus frisii. Bayesian coalescence analyses of sequence variation at two nuclear and one mitochondrial genes suggest that the Black and Caspian Seas supported separate populations of R. frisii during the last glaciation. Parameter estimates from the fitted isolation-with-migration model showed that their separation was not complete, however, and that the two populations continued to exchange genes in both directions. These analyses also suggested that majority of migrations occurred during the Pleistocene, showing that the variation shared between the Black and Caspian Seas is the result of ancient dispersal along the temporary natural connections between the basins, rather than of incomplete lineage sorting or recent human-mediated dispersal. Gene flow between the refugial populations was therefore an important source of genetic variation, and we suggest that it facilitated the evolutionary response of the populations to changing climate. [source]


Microsatellite loci for Ponto-Caspian gobies: markers for assessing exotic invasions

MOLECULAR ECOLOGY RESOURCES, Issue 2 2009
KEVIN A. FELDHEIM
Abstract We developed and tested eight polymorphic microsatellite loci for Ponto-Caspian ,neogobiin' gobies, many of which are invasive in Eurasia and North America, whose study will aid understanding of the population genetics underlying their success. We tested samples from one to two locations from 12 taxa in the recently revised genera Babka, Benthophilus, Mesogobius, Neogobius = Apollonia, Ponticola and Proterorhinus; including the bighead, Caspian, knout, monkey, racer, round, tadpole and tubenose gobies; and taxa from introduced vs. native populations, those diverging between fresh and marine waters, and those differentiated between the Black and Caspian Seas. Populations conformed to Hardy,Weinberg equilibrium expectations, averaging five to 15 alleles per locus and 0.11 to 0.67 mean heterozygosity. Allelic variation significantly differentiated among all taxa and populations. [source]


Impact of a new invasive ctenophore (Mnemiopsis leidyi) on the zooplankton community of the Southern Caspian sea

MARINE ECOLOGY, Issue 4 2008
Abolghasem Roohi
Abstract The invasive ctenophore Mnemiopsis leidyi (Agassiz), which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001,2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (four Copepoda and one Cladocera) species were identified. The total number of zooplankton species found here was 50% less than in a previous investigation performed in the same region in 1996 before the introduction of Mnemiopsis leidyi into the Caspian Sea. Cladocera species seemed to be highly affected by the invasion of Mnemiopsis leidyi; only one species, Podon polyphemoides, remained in the study area, whereas 24 Cladocera species were found in the study carried out in 1996. Whereas among the Copepoda Eurytemora minor, Eurytemora grimmi, Calanipeda aquae dulcis and Acartia tonsa that were abundant before the Mnemiopsis leidyi invasion, only A. tonsa (copepodites and adults) dominated the inshore and offshore waters after the invasion. The maximum in zooplankton abundance (22,088 ± 24,840 ind·m,3) and biomass (64.1 ± 56.8 mg·m,3) were recorded in December 2001 and August 2004, respectively. The annual mean zooplankton abundance during 2001,2006 was in the range of 3361,8940 ind·m,3; this was two- to five-fold less than the zooplankton abundance in 1996. During 2001,2006, the highest abundance and biomass of Mnemiopsis leidyi were observed during summer-autumn months coincident with warm temperatures and generally when the abundance of other zooplankton organisms was low. [source]