ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Species  (41)
  • Fingerlings  (16)
  • 2015-2019  (52)
  • 1930-1934
Sammlung
Schlagwörter
Erscheinungszeitraum
Jahr
  • 1
    Publikationsdatum: 2021-05-19
    Beschreibung: Mazandaran and Gorgan provinces have temperate climate, thus they have more potential for aquatic animal culture. There are thousands hectare of salt and useless lands in adjacent to Caspian Sea. As these areas have provided a favorable back ground for aquatic animal culture. As a result, the successful results obtained from imported gray mullet (Mugil cephalus) culture project in north climate, it has demonstrated that the gray mullet has a good biocharacteristic for culturing in pond enclosure environment and in different aquatic conditions (fresh water, brackish water and salt water). From 1998 until 2001, the broodstock yield and gray mullet artificial propagation projects were performed by fisheries research center of Mazandaran in Ghomishan prawn culture station in adjacent to Caspian Sea (East north of Mazandaran Province). This investigation executed during two stages (phases). At first stage, the goal of this project included the survey of possibility available about matured fish as well as induction of final maturation and artificial propagation for producing of broodstock and larva. In addition, in this way, we will obtain new information about gray mullet propagation and culture as marine species. We introduce mass production in aquaculture. At present research, the possibility of broodstock yield and artificial propagation of gray mullet have investigated by gray mullet fingerlings imported from Hong kong and then they have cultured in earth ponds of Ghomishan areas during five years (1994-1998). In order to broodstock production in spring 1998, two earth ponds (0.5 hectare) were prepared. 100 specimens of fish stock (1-2.5 kg weight average and 5 years of age) placed in each pond. For providing of suitable water and nutrition, fish were fed by food containing rich protein (40%) with 3-5% body weight and maintained in water with 30-35 ppt salinity. The survey of sexual maturation was performed by sampling of sexual glands through year. There were four stages in dominant female broodstocks. This survey indicated that oocytes have emerged stage 1 (immature) from March to June, stage 2 (yolk vesicle) in September and stage 4 (yolk globule) in October. Three stages (first, second and third) of yolk formation in oocytes will occur but these stages take place in October, December and January respectively. It's obvious that oocytes will progress into the end of third stage (yolk formation) and then their growth was arrested. Ovum with 600 m diameter was observed when the water temperature declined less than 18 c and day time was short (from middle autumn to middle winter), on that time, fish were induced by hormone because lack of final maturation and ovulation, there fore, natural spawning was not occurred in pond condition. Furthermore, artificial propagation of mugil cephalus was occurred by hormonal induction. Hormonal induction was utilized by inject of many hormones (LHRH, Cph, HCG). Using different components of hormones and also their different doses obtained the best results from broodstock that the average ovum diameter was about 600 m. Several types hormones which were injected into gray mullet with two or several intermittent (24 h intervals) along with 20-25 c temperature and 30-35 ppt salinity. This condition can provide stage 4 maturity for fertilization. Totally (as whole), three intermittent fertilization was necessary for exiting of larva, larva production in first, second and third intermittents that were 2000, 2500 and 300 specimens respectively. Larva fed on chlorella algae and rotifera and they have maintained for 14-15 days. The results of obtainable research indicated the possibility of gray mullet broodstock production in cultural condition, artificial propagation and larva production. This research took place for the first time in north climate of Iran.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Gray mullet ; Mugil cephalus ; Broodstock ; Production ; Yield ; Artificial propagation ; Hormone ; Temperature ; Culture ; Maturation ; Fingerlings ; Earthen ponds ; Ovum ; Spawning ; Breeding ; Reproduction
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 79pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2021-05-19
    Beschreibung: In this study, the Tagan and Sorkh rod River in province in the northwest region of Iran, were consider and physico-chemical water parameters , phytoplankton, zooplankton and benthos cumunity , were identify and were measured also measured some organoic toxin (in water) during a year (2011 )all conducted was done at three stations. The purpose of this study was to assess the quality of water for aquaculture activities and realizing fingerling fish . In most cases between Physico-chemical parameters in Tagan and Sorkhrod river,in EC,TDS ,SAL ,NH4 , Ca , Mg difference was statistically significant (P〈0.05). Mean physico-chemical factors including water temperature in Tagan and Sorkhrod river respectivity 27±0.95,26.4±0.67±,25.6 ° C, DO: 7.4±0.16, , 7.8 ±0.14mg.l^-1; pH: 7.97±0.5 , 7.77±0.6, TDS: 7994±557 , 1317±257 mg.l^-1; EC: 11920 ±838, 1583±368 µ.cm^-1; Ca: 470±57 ,Mg: 57±11 mg.l^-1, NH4 + : 0.390±0.05 , 0.141±0.03 mg.l^-1; NO2 - : 0.030 ±0.007, 0.034±0.032 mg.l^-1; NO3 - : 0.330±0.085 ,0.420±0.034 mg.l^-1; PO4 -3: 0.049±0.003 to 0.051±0.007 mg.l^-1;salinity:10091±746 ,1247±238 mg.l^-1and total hardness: 3600±460, 406±76 mg.l^-1 calcium carbonate, respectively. The samples water from Tagan ,Sorkhrod , Tonekabon and Shirod river have organo clore toxin enclouded: g- BHC, B-Endosulfan, Endosulfan sulfate,. Aldrin, DDD Heptachlor, Lindane .Results showed that concentrations of o,c.t in cases were not the limit of detection. Range of this option maximom to minimom in river were 0.10 to 0.22 mg/l . this result keep in renge of organization U.S.A .This level not dangerous for live and realize figerling fish. Phytoplankton: The phytoplankton species were identified from the five phyla, including 56 species in sorkhrod and 52 species in tagan river . In Tagan Bacillariophyta and Chlorophyta phyla 75% of total percentage phyto and in sorkhrod Bacillariophyta and Chlorophyta , 93% of total percentage phytoplankton. Zooplankton: During the study period, four major groups Holozooplankton including Rotatoria and protozoa, Copepoda and Cladocera in Tagan river and Sorkhrod were observed. Macro benthos: The benthos species were identified from the seven family, including, Cardidae, , Spionidae , Tubificidae ،Lumbriculidae , Lumbricidae , Chironomidae Elmidae. Comparison Mean biomas between Tagan and Sorkhrod show ,sorkhrod with 3.4g/m^3 biomas in tagan with0.32g/m^3 biomas has beter coundithion for realize finger ling Rutilus frisii katum .
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Physico-chemical ; Water quality ; Parameter biologic ; Rutilus frisii katum ; Fingerlings
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 50pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Publikationsdatum: 2021-05-19
    Beschreibung: To accomplish the stock assessment that pre-planned for bony-fish resources investigation started by considering two pivotal act. First gathering biometric data and second using catch statistics information for stock analyses. Implementing the research programmes five itinerant groups in Anzali, Keyashahr, Noshahar, Babolsar, Torkaman have been organized during fishing season. The biometric data were supplied in computer that distincted by each fish species and subdivided into age groups. In analyses the samples, Bertalanffy formula used for calculating average length and age, also for growth coefficient. Total mortality rate calculated by using Pauly formula, and the biomass status estimated through Cohort analysis. The catch by beach seiner cooperatives recorded 8630 metric tons, but estimation including. Poacher catch raised the harvest to 15.6 thousand tons. The total catch of Kutum reduced by 1400 tons compared with previous year, but the estimation revealed the biomass of Kutum 18.5 thousand tones, the stock stowed reduction in quantity relative to past years. Harvest exceeding the limit, fishing pressure. And employing higher fishing effort, combining releasing the Kutum seedling with shorter average length in recent years, leaded the shrinkage of biomass of Kutum resources. The Golden Grey mullet catch has been estimated 3437 metric tons, the figure showed 1500 tons increment, in comparison with previous year, nearly 24% of catch was shorter than Lm50% of this species. In Guilan province higher number of sub - size golden mullet captured, this development occured less in Mazandaran and Golestan province. Higher rate of exploitation, reduction of catch in recent years, dominating small size fish in catch composition indicated the population undergoing stress in ecosystem. Thin - lipped grey mullet only comprised 9.2% of the mullet catch - Length - structure of this fish species population formed mainly by young small size fish, the biomass of latter estimated 1100 metric tons. Catch further than maximum sustainable yield, by higher exploitation rate, and gradual diminishing of harvest, represented the resources of this fish species suffering both by high fishing pressure and un - sustainable effort, which ultimately declined the fishery of this fish species. Carp catch and its resources in Anzali region become very low, it is necessary to enhance the stock by Sea-ranching programmes. The carp resources in Gorgan region enjoy better status, but catch practices do not compatible with rule and regulation in Gorgan and Gomeyshan area. The standing stock of Gorgan carp estimated nearly 6000 tons. The information concerning carp resources indicate the stock experiencing pressure and likely the catch will diminish in future. The total catal catch of carp calculated 1900 tons. In recent years the Caspian roach resources are increasing but the bulk of harvest fished illegally and by gill - nets. The total catch of the roach during 1998-1999 estimated 1700 tons. Considering the semi - artificial propagation of roach in Golestan province, if has been concluded the multiplication of this fish species also should be planned by fisheries authorities for Anzali region. It is also advisable catching of this fish species to be regulated soon and selective catch are proposed. The catch of pike - perch during the year of 1997 - 98 jumped to 95 tons, but 90% of catch formed by young fish or sub – standard length size. Almost, all the increment of catch attributed to the releasing of millions of seedlings in the Sea which the plan has been implemented by Iranian Fisheries. Increasing the numbers of released seedlings, with higher average weight Identification of most suitable site for unloading the fries could ensure better survival rate and contribute the enhancement of resources and produce good catch for this desirable fish species. The total catch of Bream hit 18 tons, but most of the catch comprised by young fish with sub - standard size. The present formation of fisheries population of bream are the result of seedling releasing! In the Sea by Iranian Fisheries, since the catch of bream are negligible despite releasing programmes of seedling in a decade which 14million individuals until now, one could conclude the programmes do not contributed effectively to stock rehabilitation. The Caspian Barbus (Barbus brachycephalus) are at the threshold 01 vanishing, at present a few numbers are caught, therefore B.capito appeared in catch composition. The catch of latter species in recent two years are increasing. Total catch during the year of 1998 - 99 estimated 34.5 tons, biomass calculated 93 tons. Caspian vimba are small size fish which beach seiner (mesh size in bosom 30 millimeters) could not capture them ideally, bulk of the catch caught in illegal manner by gill nets. The total catch estimated 154 tons which the present fishing procedures surpassed total allowable catch (136 tons). In recent years the catch of this fish species are increasing. "Shemaya' similar in size with Vimba are caught less by beach seiner, illegal catch are considerable, the total catch in 1998 - 99 estimated 86 tons. The level of harvesting of this fish species are increasing in recent years and its population size become significant relative to last years. The main part of catch concerning Aspius fish species occured in Guilan coastal area, high fishing pressure reduced the population size, including low discharge of water in rivers during spawning period, impact negatively to reproduction. Catch statistic in 1989 showed 128 tons of this fish species are caught but in 1998 - 99 it has been reduced to 6.8 tons. It has been suggested artificial spawning could prevent its fate as endangering species. Caspian salmon catch estimated 78 tons during 1998 - 99, salmon population in Caspian Sea are supported by releasing reared smolts, which in recent years nearly 500 thousands fingerlings released in suitable rivers. After banning the gil nets application in Southern Caspian Sea, the catch of salmon in beach seining are increasing. It is necessary the released smolts in rivers being protected for its safe approach to Caspian Sea. The total catch of herring fish species in 1998 - 99 were nearly 700 tons. The bulk of the catch occur In Guilan fishing area, elimination of gill - nets usage in Southern Caspian Sea contributed the increment of herrings catch in beach seining. The herring resources in Caspian Sea reduced relative to past decades. The catch during 1913 – 1916 ranged between 130 - 160 thousand tons, in Caspian Sea.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Stock assessment ; Bony-fish ; Fishing ; Species ; Samples ; Growth ; Mortality rates ; Biomass ; Kutum ; Carp ; Survival rate ; Barbus brachycephalus ; B.capito ; Population
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 136pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Publikationsdatum: 2021-05-19
    Beschreibung: Study on Viral Nervouse necrosis (isolation, characterisation and pathogenesis) in Golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp) Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade. Unknown acute mortality occurred in wild golden grey mullet Lisa auratus and Liza saliens in Iranian waters of Caspian Sea in recent years. In order to isolation and confirmation of causative agents of golden grey mullet mortality in the Caspian Sea, a complementary research investigation project was designed in 2005 and approved immediately in Iranian Fisheries Research Organization (IFRO). Many diagnostic aspects such as Virology (Cell culture and Elctereone Microscopy), Hemathology, Bacteriology, Histopathology, Molecular biology (NestedRT-PCR), Heavy metals measuerment and Serology (IFAT and IHC) were employed in mentioned multidiciplinary project. About 322 moribund fish samples which revealed skin darkening, erratic swimming behavior such as spiral and belly-up at rest and high distention of swimming bladder. Suspected samples were collected from coastal capture sites in iranian north proviences in 2006 till 2009. Targets tissue such as brain and eye were removed in strile condition and then kept in -80oC frezzer for cell culture and Nested-RT-PCR. Other tissue samples from liver, kidney, intestine, stomach, gill, skin and muscle, gall bladder and gonads were taken and fixed in 10% buffer formalin and same parts fixed in glutaraldehyde 3% for histopathology, IHC and EM respectively. Cytopathic effect (CPE) was observed in those cell cultures just six days after inoculation with the dilutions of the tested 312 homogenate supernatants. CPE in monolayers of cells cultured (SSN-1 cell line) was characterised by thin or rounded, refractile, granular cells with vacuoles. Nine samples were positive in virology assay. Nested- RT-PCR was done on suspected tissue samples and supernatant of CPE positive samples and 21 tissue samples and all CPE positive samples were positive. IFAT was selected as a confirmatory method for identifying viral strains replicating on cell cultures and carried out with rabbit anti-betanodavirus serum on suspected tissue samples and some smears of CPE positive samples. Some bright points approved betanodavirus antigen and confirmed cell culture and Nested-RT-PCR findings. In fixed tissue samples widespread and massive vacuolation were observed in brain, spinal cord, retina and optical nerve. In order to confirmation of diagnostic findings , IHC was done with monoclonal antibody antibetanodavirus and some red-brown points were observed. Theses findings revealed expected viral antigens and confirmed previous results. Moreover, virus particles with 25-30 nm in diameter were visualized in infected brain and retina using positive staining in TEM. Also pathogenicity test was employed to confirm the obtained results. So Guppy fish Poecilia reticulata and sturgeon fry were used instead of the experimental host due to ease of handling and susceptibility. After 15 days post infection, guppy bathed in VNN-infected tissue culture with 104 TCID50 showed clinical signs similar to naturally infected Golden grey mullet, and the mortality rate reached up to 100% in 75 dpi. When target organs were examined by cell culture isolation, serology, and histopathology, all revealed the presence of virus in the Guppy. Suspected supernatant injected to sturgeon fry through intravitreous injection and widespread vacuolation were observed in brain and spinal cord buy IHC and Real time PCR were negative. In conclusion, with attntion to obtained results in this investigation such as ecological factors, clinical signs, histopathological, virological and bacteriological results, molecular analysis, (IHC, IFAT, PCR), TEM demonstration, serological and hematological findings, it could be confirmed that VNNV was the main causative agent for disease outbreak in Golden grey mullet in Southern coastline of Caspian Sea.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Viral nervous necrosis ; Golden grey mullet ; Liza aurata ; Liza saliens ; Histopathology ; Virology ; Bacteriology ; IHC ; IFAT ; PCR ; TEM ; Species ; Sturgeon ; Rutilus frisii kutum ; Rainbow trout ; Carp
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 184pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2021-05-19
    Beschreibung: This study aimed to determine domain the adaptability of rainbow trout(Oncorhynchus mykiss) fingerlings in fresh water up to 20 per thousand (grams per liter) for providing facilities for growing this valuable species in the aquatic environment with salinity unconventional been completed. For this purpose the biochemical, bloody and physiologic parameters rainbow trout were studied to determine the adjustment range .Fingerlings fishes from cold water fish farm in the province Mazandran were prepared and for experiments were transferred to the Ecological Institute of Caspian Sea . Fingerlings with an average weight 31.56 ± 0. 07 SE g and average fork length 13.80 ± 0.15 SE cm, in 3 treatments in water with salinities (fresh, 13 and 20 grams per thousand) with a density of 15 numbers in polyethylene to 300-liter tank containing the 250 liters of water testing were introduced.Fresh water from Tajan rivers and water psu13 from the water Caspian Sea and water psu20 by mixing water the Caspian Sea and Sea salt was prepared . The daily amount to 50 percent of the of water tankss been replaced .During the experimental period was for 7 days and were not fed during the experiment.The water parameters was measured during the experiment included 6 ppm dissolved oxygen, pH equal to 8.2 and temperature 15.5 ° C . In the experimental period were not observed Losses in the experimental groups . The results showed that fish gill and kidney introduced in different salinities by making appropriate changes in chloride cells in the gills through increasing the number and the volume of these cells at the base of secondary blades and tubules in the kidney tubules to create greater interior space, are adapted to By changing salinity.Relatively parameters osmolarity, sodium, chloride, magnesium, cortisol, calcium, hematocrit, hemoglobin,number of red blood and white cells in water saltier than freshwater environment was higher (0.05〈 p, Duncan). Changes in hematological and blood plasma ionic parameters and vital organs Fingerlings indicates a willingness adaptability and the ability physiological adaptation fingerling was consistent with changes to environmental salinity brackish water .So, the factors measured with increasing salinity the uptrend that the range of variation for the osmolarite 449-281 mOsmol kg, for sodium, chloride, magnesium, cortisol, respectively, 211- 151, 165121, 3 / 3 7/0, 87. 53 mmol and the calcium 22-13 mg per dL.The measured values for hematocrit 32.2- 38.8%, hemoglobin 6.2 - 8.6 g per deciliter and the red and white blood cells, was respectively, 1.2-1.7×106 and the 15.6 -18.9×103.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Adaptation ; Rainbow trout ; Gills ; Kidney ; Survey ; Oncorhynchus mykiss ; Fingerlings
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 42pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Publikationsdatum: 2021-05-19
    Beschreibung: Caspian trout (Salmo trutta caspius ) is one of the migratory fish species which lives and feeds in the Caspian Sea .This species distributed in south and western of the Caspian Sea . In order to rehabilitation of the Caspian trout in western area, the operation of the project started from the beginning of the fishing season of the 20112012. Specimens of the Caspian trout obtained from beach seine cooperatives and have been transferred to the fish farm in Asalem region .Totally, 44 specimens of the Caspian trout has been caught in two month period .Most of the fishes was from Kargan roud river . The mean length and weight of the brood fishes were 67.7 cm and 3122.7 g respectively .As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species ,we recommend to use the broods of the western region separately for rehabilitation of the stocks of this region .
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Caspian trout ; Salmo trutta caspius ; Broods ; Rehabilitation ; Broodstock ; Migratory fish ; Species ; Specimens
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 30pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Publikationsdatum: 2021-05-19
    Beschreibung: The shrimp farming success in the future will greatly depend upon increasing supplies of healthy and high quality seed for stocking ponds. The limited and inconsistent availability of wild shrimp postlarvae together with an urgent need of establishing selective breeding programs, increased the interest in captive broods of penaeid. Many investigations have been carried out on several shrimp species world-wide. This study have been conducted on 2 shrimp groups since September (Mehr) to July (Tir) 1999 in Bandar-e-Imam southwest Iran. The wild group (SPB) prepared from Jask area and the pond group (POB) prepared from artificial ponds upon harvesting them as marketable size have been investigated. 2 groups were exposed to natural diets consisting of squid and artemia biomass in same conditions using 12 m3 concrete tanks. Stocking density was 2 piece/m2 (1F:1M). Half part of the pond bottom covered by fine sand to reduce the stress where the other part has been used for feeding. Daily ration given in 3 times by satiation method. Also reproductive performance of wild gravid brooders (WLB) were recorded as a control group. 2 examined groups well grown and around 50% of the SPM and around 30% of POB females successfully ripened a produced eggs and nauplii where almost all males of both groups were matured. Data showed fecundity is highly correlated to the TL and W of the brooders by positive trend. Considering the TL, W, Fecundity and nauplii production the WLB brooders are significantly (P=0.05) higher than 2 other groups, while the SPM broods are significantly (P=0.05) higher in hatchability. Meanwhile the survival rate from nauplii to postlarvae stage was around 30% for SMP brooders. On the other hand the growth parameters (TL, W) of the marketable size of the shrimps produced from SMP brooders were significantly (P=0.05) higher than those produced from WLB group. Since the fecundity is improvable by increasing the brood size thus the data suggest the sup.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Fatty acids ; Penaeus indicus ; Brood ; Juvenile ; Shrimp ; Postlarvae ; Species ; Squid ; Artemia ; Biomass ; Nauplii ; Fecundity
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 42pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Publikationsdatum: 2021-05-19
    Beschreibung: The fishery stocks of most commercial aquatic stocks in the world have shown declining trends in the past two decades. Several factors have been responsible for the decline of stocks the most important of which over fishing and over-exploitation, pollution, loss of natural habitats and natural spawning grounds, construction of dams and bridges across the important rivers which restrict the migratory routes of spawners, decrease in natural reproduction and rehabilitation of stocks through artificial breeding programs. Over-exploitation of stocks and pollution directly affect decreasing stocks in an ecosystem. Not differentiating between different populations and stocks of a species found distributed in an aquatic ecosystem is considered one of the main factors which causes the depletion of stocks in most ecosystems in the world. In most cases this is because genetic variations in aquatic stocks in the wild are not taken into consideration. Six species of sturgeons are found living in the Caspian Sea and its drainage basin which produce more than 85-90% of the world caviar. The Persian sturgeon (Acipenser persicus) and the stellate sturgeon (Acipenser stellatus) are the main sturgeon species of the Caspian Sea. The Persian sturgeon is mainly found in the south Caspian Sea while the stellate sturgeon stocks are considered shared stocks by the five Caspian littoral states. Due to over fishing in the past two decades the legal catch figures for sturgeon stocks in the Caspian Sea dropped from 28500 tons in 1985 to less than 1500 tons in 2004. Similarly caviar production also dropped from 3000 tons to 110 tons in 2005. With regard to the severe reduction in sturgeon stocks it is necessary to take essential steps before these valuable species are totally wiped out. The fisheries management of the five Caspian littoral states should focus their efforts on identifying the different populations and stocks found in the Caspian Sea. Concerted measures should be taken to study the distribution and biomass of the different populations in order to develop a scientific solution for the sustainable use of these endangered species and to secure the long term conservation of sturgeon stocks. The aim of present study was to evaluate the genetic structure of the population of two species Acipenser persicus and Acipenser stellatus and to develop molecular markers to identify and differentiate different populations of these two species.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Commercial ; Population ; Genetic ; Persian Sturgeon ; Acipencer persicus ; Stellate Sturgeon ; Acipencer stellatus ; Microsatellite markers ; Fishery ; Pollution ; Spawning ; Species ; Aquatic Ecosystem ; Genetic ; Molecular
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 70pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Publikationsdatum: 2021-05-19
    Beschreibung: During the past decades the environmental status of the Caspian Sea has changed. Therefore, study on the biological structure such as: age, growth, Lm50%, feeding of fishes is necessary. In the present study the biological characteristics of some commercial important species including kilka, kutum, golden grey mullet and carp were studied during 2006-2010. Kutum, golden grey mullet and carp predominated in the catch composition of bonyfishes, representing 61.3, 29.6 and 7.6% of the total catch. The average fork lengths of kutum, golden grey mullet and carp were 38.4, 32.7 and 36.7 cm, and weights were 784.5, 411.0 and 977.0 g, respectively. The values of b in length-weight relationships were 3.02 and 2.97 for kutum and golden grey mullet indicating an isometric growth. The value b for carp was 2.89, indicating an allomertic growth. The maximum age of three species was 12 years. Von Bertalanffy growth equations were estimated as: for kutum: for golden grey mullet: and for carp: The sex ratio of three species showed that females were dominant. Spawning migratory of kutum was started in March. The gonadosomatic index value of kutum peaked in March and April. The spawning season of carp expended from March to August. The gonadosomatic index value of golden grey mullet peaked in September and then declined in November and December. Absolute fecundity of kutum, golden grey mullet and carp were 64400, 700800 and 131000 eggs, respectively. Length maturity (Lm50%) of three species were 39.07, 28.4 and 31.6 cm, respectively. The highest feeding intensity (Gastrosomatic index=GSI) for females and males were 313.9 ± 65.9 and 350.7±103.7 in October; and the lowest value of GSI were 19.4 ±59.2 and 144.1±85.04 in March, respectively. There are significant different between GSI with male and female in difference months (P〈0.05). Main prey mature of Kutum was Cerastoderma lamarki; Gastropoda and Balanus were subordinate, and Crab, Hypanis, Fish (Neogobous sp.) Algae, egg, and scale were random preys. Planktone groups comprise to Exuviaella, Nitzchia, Osillatoria, Synedra, Nematoda, Navicolla, Diatoma, Rholcosphenia were preys juvenile of Kutum. Based on ISI (Important species index), Cerastoderma lamarki and Balanus were dominant species in feeding of Kutum. The percent of empty stomach and prey dominant evaluated during different seasons by specific formula result showed that in Cyprinus carpio prey Molluscs was dominated and specific food items. Empty stomachs in winter and spring were higher and lower, respectively. The results showed that catch of kilka decreased from 22300 mt in 2006 to 16700 mt in 2008, but the CPUE increased from 1.7 mt (Vessel×Night) to 2.5 mt, due to decrease of effort, respectively. The length frequency of three species of kilka is close and the juvenile fish did not see in catch. The age frequency had the same situation as fish lower than 2 years was not in the samples of anchovy and bigeye kilka. The parameters of the von Bertalanffy growth curve were: For common kilka: L =136.5 cm, K=0.249 yr-1 and t0= -1.89 yr-1 For bigeye kilka: L =148. cm, K=0.346 yr-1 and t0= -1.123 yr-1 And for anchovy kilka: L =131.7 cm, K=0.375 yr-1 and t0= -1.243 yr-1 The exploitation rate of anhovy, bigeye and common kilka were 0.51, 0.58 and 0.6, respectively. The highest of GSI for common and bigeye was recorded in May and March, respectively. For anchovy kilka it was in July and November. Main prey of anchovy and common kilka was Acartia tonsa and for bigeye kilka it was Cypris balanus. We concluded that the ecological problems caused by Mnemiopsis leidyi as well as overfishing have been collapsed kilka stocks, particularly anchovy. Therefore, sustainable fisheries management and conservation biodiversity in the Caspian Sea are real challenges now.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Commercial ; Growth ; Species ; Kilka kutum ; Bonyfish ; Sex ratio ; Spawning ; Gonadosomatic ; Maturity ; GSI ; Hypanis ; Neogobous sp. ; Algae ; Nitzchia ; Cyprinus carpio ; Diatoma ; Clupeidae ; Rutilus frisi kutum ; Liza auratus ; Chalchalburnus chalcoides ; Vimba vimba ; Abramis brama ; Sander lucioperca ; Liza saliens ; Fish
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 98pp.
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Publikationsdatum: 2021-05-19
    Beschreibung: Jajroud river with 140km length, inhabits various species of aquatics of which one of the main identified one is freshwater crab belongs to POTAMIDAE family with scientific name of Potamon persicum. In this study, 388 specimens from 5 sampling stations (Latian dam, Taraghion, Khojir, Giahan daroie and Mamloo dam) were collected since November 1998. All samples were transferred to the laboratory for reproduction studies and determination of spawning season, with studying the maturity stages of gonads and external eggs. The results showed that the spawning season of this species occurring in middle of spring, it was also found that P. persicum is a total spawner. The external maturity (of eggs) was classified to 7 stages. On the other hand the maturity stages of gonad was recognized in accordance with the color, size and egg diameter and classified to 5 stages.
    Beschreibung: Published
    Schlagwort(e): Spawning ; Maturity ; Potamon persicum ; Freshwater crab ; Species ; Aquatic ; Potamidae ; Gonads ; Eggs ; P. persicum
    Repository-Name: AquaDocs
    Materialart: Journal Contribution , Refereed
    Format: pp.69-86
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...