ALBERT

Beschreibung: Caspian trout (Salmo trutta caspius) is one of valuable fishes of the Caspian sea for people living in the Northern coastal area of Iran. Since fish stock and natural resources protection is one the Iranian fisheries research objectives, the most activity on Caspian trout rehabilitation was focused on releasing thousands of smolts in the rivers discharge to Caspian Sea. Catch statistics of this species has declined over last decades thus this study on quality of provided brood stocks and producing fries with suitable quality can help rehabilitation and rearing of this valuable species. Several rivers were considered for providing brooders to keep genetic resources variety of sea stocks. In spawning season 25 (9 male, 16 female) and 30 (5 male, 25 female) brooders were collected from fishermen in Mazandaran rivers and Gyilan coasts provinces respectively. After propagation and larvae rearing, 11500 (10-15 g.) and 50000 (less than 10 g.) juveniles were released in Gyilan and Mazandaran rivers respectively.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: Larvae of the chironomid midges (blood worms) are known as use full live food for cultured aquatics. There are endemic blood worms in sediments of the earthponds of Bafgh area at center of Iran. This study tended to identification of two chironomid species, Chironomus aprilinus Meigen, 1830 and Dicrotendipes sudanicus Freeman, 1959 & 1961, from Iran as a new record. Culture of blood worms was successful in glass thanks with 16h. light, at 24-26°C temperature. Eggs were incubated after 14 days. Suitable concentration of harvesting is 1-2 egg masses (1250eggs/m2). Enrichment of earthponds or plastis thanks including sedime is offered for culture of chironomid larvae. Collectors prepared with low cost materials are useful for collection of egg masses. May, June and July are the best time for egg collection. Large blood worms are mainly avalable in winter. Results of body analysis of the larvae indicated high dry matter with good quality.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment and Acceptable Biological Catch (ABC) of bony fishes in the Iranian coastal waters of Caspian Sea in the years 2010-2011 and 2011-2012. According to the result, the numbers of beach seines were 131 and 128 and their fishing efforts were observed 50184 and 42255 beach seining during 2010-11 and 2011-12, respectively. The catch per unit of effort CPUE) was calculated 182.9 and 205.6 kg/haul during two sampling periods, respectively. The total catches (including illegal fishing) were also obtained 16601.5 mt and 17034.1 mt during 2010-11 and 2011-12, respectively. The highest proportion of catch was belonged to kutum and golden grey mullet (86% and 88%, respectively) in two fishing seasons aforementioned above. Growth parameters of kutum were estimated as K=0.21/yr, L∞ = 60.0 cm, t0 = 0/yr. The Growth parameters were K=0.18/yr, L∞ = 61.1 cm, t0 = -0.14/yr for golden gray mullet and were K=0.12/yr, L∞ = 73.6 cm, t0 = 0.92/yr for common carp. Based on catch-at-age data, in the years 2010-2011 and 2011-2012, the total biomass, from the biomass-based cohort analysis were estimated 41700mt and 34400 mt for kutum and 14600 mt and 14400 mt for golden grey mullet, respectively. The reference points of F0.1 and F35% were 0.41/yr and 0.34/yr for kutum and 0.36/yr and 0.33/yr for golden grey mullet, respectively. Stock enhancement plays an important role in recovery of kutum stocks in the Iranian coastal waters of Caspian Sea. There is a significantly negative correlation between fingerlings released and condition factor (CF) and recruitment and CF. The different trends for fingerlings, recruitments and CF suggest that CF may be partly density-dependent, declining at high population sizes due to intra-specific competition. Therefore, more research should be conducted to determine the desirable level of artificial propagation. Food consumed by fish species, Rutilus frisii kutum, Rutilus rutilus caspicus, Cyprinus carpio, Liza auratus and Liza saliens were included Foraminifera, Porifera, Annelida, Mollusca, Arthropoda, filamentous algae, fish eggs and detritus.The results showed that Rutilusfrisii kutum generally feed on Balanus and Cerastorderma. The main food item for Cyprinuscarpio, Liza auratus and Liza salienswas detritus. Based on available models, the ABCs were estimated as 6600-7400 mt for kutum and 2200-2800 mt for golden grey mullet (with precautionary approach 6600 mt and 2200 mt for kutum and mullet, respectively) in 2011-12. Two species (kutum and golden grey mullet) are vulnerable to environmental factors, and these factors should be considered in the stock assessment and management of the fish. For two species, the ABC with a lower andmore accurate value based onmore information, should be selectedfor the implementation of a precautionary management approach.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: In order to domesticate Litopenaeus vannamei as a solution to single species shrimp aquaculture of Penaeus indicus and to reduce risk of shrimp culture in emergency cases, this study was carried out. Initially the postlarvae reared from imported L. vannamei were cultured. After culture season the adult shrimps were transported to greenhouse ponds for wintering. It is then relocated to hatchery saloon. After eye stalk ablation and maturation the female brood stocks were introduced to matured male for copulation at ponds. During the study period, male and female shrimps attained full maturation at end – April by temperature over 25ºC, the copulation process was started significantly. Finally of the 12 instances of copulation, one instance resulted nauplii production. The best maturation was observed at 28 ֯C ±1 and salinity30 to 33PPT and pH of 8 to 8.3 Fresh sea worms and squid showed the highest effect on fecundity in brood stocks. Besides, the spring season was obtained to be the best period for brood stock production in Bushehr province.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: An artificial Reef is a fabricated, underwater structure, typically built for promoting marine life in areas of generally featureless bottom. Creating artificial reefs began from 2000 in southern provinces in Iran. This study has surveyed about the Bushehr and Khozestan states. The objective is to determine the effectiveness of artificial reefs in attracting and enhancing the production different aquatics through increasing of fish assemblage and fishery. The performance of artificial reefs deployed off the coast of the Persian Gulf in 10 to 15m, was evaluated. The reefs comprised of seven artificial and one control (natural) statistical tests plan in three replicates. Three types of artificial reefs were used in this study. That two were designed reefs and one was not designed or used material. The experimental plan consisted (i) Reef ball (R), designed hemispherical shaped; (ii) Laneh Mahi (L), designed pyramid shaped; (iii) Used material (U); (iv) mixed (RL); (v) mixed (RU); (vi) mixed (LU); (vii) mixed (RLU); and (viii) control site (CS). Trap nets and under-water visual census surveys were adopted for seasonal sampling of fish aggregation. Results of statistical analysis using ANOVA and T-test of the mean Catch per Unit Effort (CPUE) showed significant difference (p〈0.05) in term of computing number of fish for aggregation of fishes. The study has concluded that reef deployments have influenced favorably the fish communities and fish harvests. Therefore, the artificial reefs, especially the mixed RLU, are appropriate tools for future fishing enhancement in the Persian Gulf of Iran.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The silver pomfret, Pampus argenteus, is distributed in Indo-western pacific ocean, especially in Persian Gulf and Oman sea, and although is widely commercially exploited, the genetics structure of this species is not clear completely. In the present study, the genetic diversity and population structure of Pampus argentus in the Persian Gulf and Oman Sea were investigated using microsatellite DNA markers. Genomic DNA from 125 specimens was extracted and PCR amplification performed. Seven loci with reasonable polymorphism were amplified. The results showed that average of observed heterozygosity was ranged from 0.54 while expected heterozygosity was 0.67. After applying the Hardy-Weinberg Equilibrium (HWE) test, some loci were found to be significantly deviated from HWE in some populations in which deficiency of heterozygotes was apparent. Population differentiation observed among all populations (P 0.01). The population differentiation (Fst) value between Kuwait and bushehr was the highest and significant (0.087) and between Chabahar and Bushehr (0.021) was the lowest and significant. Genetic distance analysis showed that the largest distance (0.269) was between Khuzestan and Chabahar and the smallest distance (0.075) was between Bushehr and Chabahar. The reported results could be of interest for management and conservation programmes of this species in the Persian Gulf and Oman Sea.

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: Striped grey mullet (Mugil cephalus) is a marine fish with high commercial value and widespread distribution. The grey mullet and some other mullets can be found in saltwater, brackish and fershwater habitats at tropical, subtropical and also temporal climates.This species is suitable for aquaculture worldwide due to living in wide ranges of water temperatures and salinities, acceptable growth rate, suitable food conversion ratio, marketability, suitable species for polyculture with shrimps, marine fish and even with freshwater carps. The grey mullet is farming in different countries such as Italy, Northern Africa countries ( Egypt), occupied Palestine, India, Pakistan, Japan, Hong Kong, Taiwan, Vietnam, Indonesia, coastal countries of southern pacific ocean and Hawaii. Ten thousands of fries of this species (average weight and length of 280 mg and 28.3 mm respectively) imported in March 2008 from Egypt. The wild fries colleted from surrounding natural waters of Alexandria. After finishing the quarantine steps, they stocked in four earthern ponds (each with 2500 m2) located at the Gomishan shrimp educational centre at late march in 2008. At the first year of culture the densities were 5000 and 10000 individuals per hectar and each treatment with two replicates. At second years densities changed with 2000 and 2500 ind./hec. and each of traetments divided fishes with average primary weights of 80 and 115 grames. The fries and fish feeding begins in April when the water temperature rise above 18 °C and it cut in fall when the temperature goes under 20°C. They fed twice a day at 8 AM and 2 PM and the amount was 5-7 percents of the fish existent biomass in each ponds. They fed with dry formulated feed made of Mahdaneh Karadj Company (Danso dry feed) both the first and second years of farming. The feed prepared for carps feeding and containded 23±2 % crude protein, 10 ±2 % crude lipid, about 7 % crude fiber, 15 % ash, 40 ±2% carbohydrates and with energy content of 4000±200 kcal/kg. After seven months culture period the average weight and length of fish in treatment 5000 ind./hec. were 113.7 gr and 21.1 cm respectively and in treatment 10000 ind./hec. the average weight and length were 86.6 gr and 19.6 cm respectively. At first year the average survival rate in different treatments was 77 percent. The average FCR in treatments 5000 and 10000 ind./hec. were 3.4 and 3.9 respectively. At second years after six months culture the average weights in pond no. 9 (with primary weight 115 gr and density 2000 ind./hec) , pond no. 10 (with primary weight 80 gr and density 2000 ind./hec) , pond no. 11 (with primary weight 115 gr and density 2500 ind./hec) and pond no. 12 (with primary weight 80 gr and density 2500 ind./hec) calculated as 476.6 ,338.1, 366.5 and 440 gr respectively. The average survival rate and FCR were 93 % and 3.1 respectively. Ponds no. 9 and 11 (fish stocked with primary weight 115 gr in densities both 2000 and 2500 ind./hec) selected as the best economic efficient treatments.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: Feeding habits of three dominant species of tuna fishes (Thunnus tonggol, Thunnus albacares, Euthynnus affinis) and dominant species of sardine (Sardinella sindensis) were investigated from December 2006 to November 2007 in the western waters of Oman Sea. Seasonally samples of three species of these tuna and monthly samples of sardine were collected. Feeding studies on 101 longtail tuna (T.tonggol) indicated that the bony fishes were main food of this species (98.3%) and followed by random foods included cephalopods (1.7%) and crustaceans (1.7%). Among the bony fishes, anchovy (66 %) and sardines (25.9 %) were most important than the other fishes. FI and CV for this species were calculated 26.4 and 21.8 respectively. Stomach content analysis of 85 specimens of E.affinis demonstrated that bony fishes were only food for this species (100%). Sardines (49.3%) and anchovy (11.9%) were foremost food items for E.affinis. Moreover FI and CV were calculated 64.7 and 15.3 correspondingly. The stomach of 120 yellowfin tuna (T.albacares) were analyze. Results showed that bony fishes,cephalopods and crustaceans were formed food items of this species .Yellowfin tuna were preferable fed on bony fishes (87.7%) specially sardines(41.2%),flying fish(13.9%)and M.cordyla(10.4%) and followed by cephalopoda (43.8%) specifically Loligo sp.(84.5%) and crustaceans(11.2%) . FI and CV were calculated 38.3 and 25.8.Study on 320 stomachs were determined that zooplankton and phytoplankton formed food of S.sindensis. Zooplankton (crustacean and molluscs) were main food (90%) and phytoplankton (Bacillariophyceae and Dynophyceae) were least food items (10%). Copepoda (crustaceans) with 58% were preferable food and bivalves and after that bivalves (molluscs) with 14%, Bacillariophyceae (8%) and Cyanophyceae (2%) CV and FI were 30.3 and 29.4 respectively.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published