ALBERT

Beschreibung: Samplings were carried out weekly in coastal waters of the Guilan province (Caspian Sea) by a hand net with 0.5mm mesh size during 1996-1997. The results of one year sampling showed that the mean total length(T.L.) of this shrimp (pooled data of females and males) was 28.58±5.58mm (x±SD), and were 26.46±4.30 and 30.01±6.30mm in males and females, respectively. For ovigorus females, mean T.L was 36.16±3.13mm, also the minimum and maximum T.L of the males were 12.6 and 41.1mm, respectively. In females these figures were found 10.7 and 43.4mm, respectively. The length-weight relationship for the males and females were determined as W=0.0002 TL2.97 (R2=92.13) and W=0.00002 TL2.98 (R2=92.84), respectively. Spawning season was determined from May to September. The average absolute fecundity was 796±320, with a range of 360 and 1660. There is a direct retationship between fecundity and T.L. Females provided 59.42% and males 40.56% of the population, the sex ratio deviated from 1:1 (P〈0.05). The growth coefficient of Loa for females, males and pooled data based on powell-wetheral methods were 42.6, 34.4 and 42.5, respectively. The growth coefficient of K based on Shepherd method were 2.1, 2.3 and 2.5 for females, males and pooled data, respectively. Natural mortality rate (M) calculated as 2.29, 2.29 and 2.28 per year for females, males and pooled da1a, respectively. Total mortality rate was calculated as 2.38, 2.50 and 2.61 per year for females, males and pooled data, respectively.

Beschreibung: Published

Beschreibung: In this research was used sodium chloride in feed supplement to stimulate ion- osmotic regulation system of Rutilus Kutum juveniles (about one gram) in fresh water environment.The purpose of this experiment was to improve survival and growth ability of juveniles’ fish in brackish water during times of transition. The initial average weightes of Juveniles’ fish were 0.91±0.01 g (mean±SE). Experiments carried out in two phases. In step one, the Juveniles’ fish were kept for 15 days in fresh water and fed with commercial diet plus NaCl supplement (control without NaCl supplement, 5, 7 and 10 percent) in four treatments, each treatment inclusive three replication. In the second step, the fish transferred to brackish water (12.5 psu) and fed for 28 days with a commercial diet (without NaCl supplement). The results showed that no change compared to control treatment in renal tissue in step one. The difference between the kidneys were not in fish fed with NaCl supplement and without it. Nevertheless, a significant difference was observed between the size of the glomeruli and renal tubules between fresh and brackish water environments (between stage one and two), (P〈0.05). In step one, were observed in the gill accessory cells in treatments fed salt supplements. At the end of the second step, the number of gill chloride cells in fish fed with salt supplementation was more than control (P〈0.05). In addition, the highest and lowest weight gain was obtained in treatment two and four respectively (P〈0.05), and no significant difference was observed between control and treatment 3 (P〉0.05). The results showed that the fish fed dietary supplements of sodium chloride 10% versus the control treatment had less weight gain. Therefore, the was obtained the highest weight gain and growth performance (condition factor, specific growth rate) and the highest feed efficiency and protein efficiency ratio and the lowest feed conversion ratio in treatment 2 with the feeding of 5% NaCl in dietary supplements.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The project of Age, growth, feeding regime and fecundity of Kutum (Rutilus frisii Kutum) survey started in south of the Caspian Sea from 2006 to 2007. The aim of project was related to determination of length maturity (Lm50%), identification of feeding animals, and investigation some of biological aspects uncluded in sex ratio, growth and age structure in southern of the Caspian Sea. Total 2706 specimens of Kutum were surveyed. The age structure of Kutum has nine age groups that included in 1, 2, 3, 4, 5, 6, 7, 8, and 9 years. The result showed that maximum frequency was about 39.3 % and were belong to 4 years and minimum frequency which was about o.1 % were belong to 9 years. The maximum and minimum fork length and weight were 58 and 21cm with mean (±SD) 38.4 (± 6.4) cm; 2450 and 104g with mean (±SD) 784.2 (± 383.30) g , respectively. There are significant different between fork length and weight in male and female of Kutum at difference months (ANOVA, P〈0.05). The sex ratio of males to female was 0.65: 1 (males: females). The least and high condition factor was 1.5 in January and 2.17 in October, respectively. Length maturity (Lm50%) was 39.07cm. Minimum and maximum absolute fecundity was varied from 15713 to 130737 eggs with mean (±SD) 69961.7 (± 3836.4). Significant different was between absolute fecundity with fork length and weight (p〈0.05). Gonadosomatic index (GSI) mean for females were 2.5±0.2 (autumn) and 17± 0.2 (spring); 1.2± 0.1 (autumn) and 4.1± 0.2 (spring) for males, respectively wich coincided to spawning period. The highest feeding intensity (Gastrosomatic index) for females was 313.9 ± 65.9 in October and 119.4 ±59.2 in March; 350.7 ±103.7 in October and 144.1±85.04 in March for males, respectively. There are significant different between GSI with male anfemale in difference months (ANOVA, p〈0.05). The Bertalanffy growth equation for all populations of Kutum was L (t) = 63.92[1-e ^0.19 (t (-1.00) ]. 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. As a result, growth, fecundity and length maturity of Kutum declined which may due to loss natural breeding area, overfishing (overlapping between fishing and spawning period) and artificial breeding that commenced since 1982. Hopefully, this information can be used in fisheries management.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment of Caspian Sea mullets in the Iranian coastal waters of Caspian Sea in the fishing season of 2013 - 2014. For gathering of data on biometry and catch statistics, 5 mobile working group in the regions of Anzali , Kiashahr , Noshahr , Babolsar and Torkmen were involved from the start to the end of fishing season.Gathered data Were entered to the computer. For data analysis , common methods were undertaken for estimation of growth parameters , mortality rates , biomass and Maximum Sustainable yield ( MSY ) as well. . According to the result, the number of beach seines cooperatives was 124 and fishing efforts were 44688 beach seining haul . The catch per unit of effort CPUE) was calculated 53 kg/haul during this fishing season . The total catches of Caspian Sea mullets (including illegal fishingestimated as 2373 mt. Growth parameters of golden gray mullet (Liza aurata ) were estimated as K=0.16 /yr, L∞ = 57.4 cm, t0 = - 0.45 /yr. Based on catch-at-age data, in the fishing season of 2013-2014 , the total biomass, from the biomass-based cohort analysis were estimated 12473.3. mt. Based on these results , the fishing mortality rate in fishing season of 2013-2014 were 0.575 /yr . In this survey , the Maximum sustainable yield were estimated as 2558.6 mt respectively . Generally from three Northern province's cooperatives 3406 sampels collected.Results of biometry of golden gray mullet (Liza auratus) showed that the mean length and weight and age of this species were 32.3 ± 6.1 cm and 383.5 ± 74.823.4 g and 1.2 ± 5.6 y respectively and leaping gray mullet (Liza saliens) showed that the mean length and weight and age of this species were 24.8 ± 3.3 cm and 119 ± 25.5 g and 2.5 ± 0.6 y respectively . The biometric results showed that ,97.5 % of the samples belonged to golden gray mullet and population of leaping gray mullet was sever declined. Also , the fishing of the mullet was increased over the last year by 10.3 % from 2151 tones to 2373 tones per year during 1391-92 and 1392-93 , respectively .

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The aim of this project is to study the growth and age structure in the Caspian trout, comparison with other coldwater species and check the trend of these parameters in recent years. This study was conducted during 2013 till 2015. Totally, 43 specimens for back calculation and 101 specimens for biometrical study of the Caspian trout have been caught in two month period. Biometric parameters such as length, weight and age of the fish were recorded. Base on Back calculation method in 1393, the average length of fish at ages 1, 2 and 3 years old were 18.98 ± 3.5, 30.5 ± 7.24 and 41.7 ± 9.1 cm. So these age groups are under the adult age and don’t approaching to near the beach and rivers for spawning behavior. Therefore, these length groups cannot be observed in catch composition. The result showed, the mean of gonad weight in this fish was about 11 percent of total weight and number of eggs per gram of gonad calculated about 10.8 numbers. Minimum age and maximum age of this species determined 4 years and 7 years (mean = 5.6) and the most frequency allocated to 5 age group and the frequency of 6 and 7 years has been remarkable. The average length of salmon was 69.2 ± 6.2 cm (minimum 57 and maximum 81 cm) and the average weight was measured 3323 ± 677 g (2400 to 5600 g) in the catch composition. Growth parameters such as k, L∞ and ø’ was measured 0.18, 104 cm and 3.289 respectively. The amount of b for relation length and weight was 2.9 which imply negative allometry. L∞ and growth coefficient (K) on the Caspian trout were acceptable range, that it shows good growth the fish in the sea water. Most of the fishes were catched from Cheshmehkileh River. As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species, we recommend using the broods of the western region separately for rehabilitation of the stocks of this region.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

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

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

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

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

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