Study on optimum exploitation of silver carp (Hypophthalmichthys molitrix)

The increasing demands of the growing populations can be met by developing aquaculture. However in order to provide suitable grounds for consumption which is acceptable to different conditions and tastes, apart from producing a variety of products we also need to improve the methods of marketing and consumption. The silver carp (Hypophthalmichthys molitrix) comprises about 50 to 85% of the composition of fish species in the polyculture of warm water species in Iran. However the difficulty in pretreatment of this species and the presence of pin bones are among the main reasons to restrict the demand of this species in the domestic markets, particularly in non-coastal provinces. In this project different aspects of silver carp processing studied as follow: 1. Use of fish fillet residuals in preparation of snack, cheese and ice cream 2. Use of fish meat in sausage and fish ball produce 3. Use of machinery to produce of without or low bones fillet and trimmed fillets. Fish sausages were studied in four experimental groups; Based on the results obtained it was evident that sausages in the experimental Group 1 (65% minced fish & 12 % soy bean oil) showed better taste and flavor as compared to those in the other groups. Fish ball were prepared using starch from four different sources (wheat, corn, potato and tapioca). Thirty different trials were tested by adding each starch source either individually or by mixing equal proportions of two sources of starch at a rate of 5, 10 and 15% to 80% ground meat of silver carp. Among trials containing two sources of starch, mixed trials with potato and wheat (5% potato + 5% wheat) were rated higher in organoleptic tests as compared to the other trials. Fifteen formulas were worked for preparing of fish cheese. The quality assessment of product showed that fish cheese in zero and 30 days after storage in 4֯ C were good and medium, respectively. Quantity enrichment of corn snack with FPC until 33% in fish snack preparation, have a best results among with other experiments. Fish ice cream made from fish protein concentrate type a that produced from silver carp in three steps by the extraction with isopropyl alcohol solvent and heat. The result showed that FPC replaced with 30%milk in ice cream formula has a best quality score. On the basis of recent findings, the deep part and a upper part on the back of the fish, like a relatively narrow band, are considered as boneless parts in silver carp. The aims of trimming project introduce best type of fillet trimming and machine for Silver Carp fillet. The results show percentage of waste in trimming by machinery line processing was less than handing, and fillet trimming speed by hand was most than machinery .Also final results of this study show machinery method or complex of handing and machinery for Silver carp fillet trimming are the best .speed rate in pine bone removing from silver carp fillet in handy method with using of transparent table and machinery method were 30-40 min per fish and 15 second per fish, respectively. Removing efficiency of bones from fillets in handy and machinery method were 50-60 and 90 %, respectively

The study of some limnological study of the Kan river in the catchment area of the Persian Gulf Martyrs Lake (Chitgar), Tehran trophic index in Anzali lagoon

This study focused on identification phytoplankton, zooplankton, benthos, fishes and relationship between biotic and abiotic parameters at three stations in the Kan river during 2014. This study identified 19 phytoplankton taxa. The findings showed, the diatoms abundance were dominated in the river. The chlorophytes abundance were recorded the lowest abundance in this study. The nutrients and water temperature were the significant abiotic parameters to increase cyanophytes and chlorophytes abundance in the Kan river. This study identified 26 zooplankton taxa. The Rotatoria and Protozoa abundance were dominated in the Kan river. Based on CCA, there was no correlation between abundance zooplankton and abiotic parameters. The biodiversity index of plankton was between 1.8 and 2 and the lake situation is located in the mesotrophic category. The study of the Kan river fishes showed, only one endemic fish species Capoeta bohsei. The length (between 38 and 270 mm, average 144±86 mm) and weight (between 1.1 and 356 g, average 108.8±146.7 g) of the C. bohsei were varied during the study period. The 19 benthos taxa were identified. The Ephemeroptera was most abundant in the benthos groups. The classification of river based on biology indicator and environmental parameters confimed that water quality is located in the moderate category

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)

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

The feasibility study for culture of Salmo trutta caspius by brackish water

Caspian trout is valuable, Commercial, anadromous and endemic fish species in the Caspian Sea so that, researchers attention have been focused on this species. At the moment, only pay attention to stocks rehabilitation that fisheries organization releases more than 300,000 fingerlings to the rivers ends to the Caspian Sea. Importance of this study consist (1) introducing a new species to the aquaculture system and (2) provide breeders in this research. we used from 2 treatments that consist with density of 10 kg/m^3 and 20 kg/m3 with 3 replication. Results showed, culture of Caspian trout is suitable with density 10 kg/m^3, so that weight gain, SGR and Daily growth mean are better than treatment 2(15-20 kg/m^3