ALBERT

Description: Study of survey health management and diseases in hatcheries and fish farms can help us to knowledge and application control methods such as: prevention, treatment and increase high levels of production in hatchery and farms, finally. This survey carried out from 2005 to 2008 for 4 years in sturgeon hatcheries and farms of Golestan province. Sturgeon fishes include Huso Huso, Ship sturgeon, Acipenser persicus collected and for virology, bacteriology, fungius and hematology examined. Also, physicochemical parameters measured and recorded in different stages of culture. Results of this study showed that all of samples in virology was negative and did not observe any doubetful causes. In bacteriology CFU was variation from 3/9 ×105 to 6/9×10. The most parasites that detected in this survey was Cocolanus espherolanus , Sceria binopsulus semiarmatus and Amphilina fuliacea that separates from Acipenser Percicus, especially. The results about hematology parameters some important hematological indices of ship sturgeon include: The total RBC for female and mail specimens measured as 5.3±1.5 ×105, 4.8±0.5 ×105 per mm 3 respectively. The amount of haematocrit and hemoglobin for female and mail determined: 34.3±2.8, 35±1.4 percent and 10.3±0.9, 8.9±0.8 gr/dl .The MCV: 216.3± 96.2, 736.5± 102.5, MCH: 720.2±309.5, 186±0.7 and MCHC: 30±0.8, 25.5±3.4 percent respectively.The total WBC were (female, male): 21320±1054, 20580±777 per mm 3 and neutrophil: 16.4±2.5, 17±1.4 percent and lymphocyte: 74.4±2.4, 73.5± 0.7 percent and eosinophil: 6±1.4, 6.4±0.5 percent, monocyte: 2.8±0.8, 3.5±0.7 percent. There was not any significant differences (p〉0.05) between mentioned parameters in male and female (students t-test). Also evaluation of hematological parameters in bluga ( Huso huso) include: total RBC were (male , female) 5±0.3 ×105 , 4.9±0.6 ×105 per mm 3 ,respectively and hematocrit: 33.2±6.7 , 35.4±3.4 percent and hemoglobin: 11.2±1.5 , 12.2±1gr/dl and MCV: 669.9±172.2, 723.9±982.4 and MCH: 226.2±42.5, 249.5±35.4 and MCHC: 34.1±2.4, 34.6±3.6 percent respectively. The totals WBC were (male, female): 24800±707.1, 23042±1375.4 per mm 3 and neutrophil: 18.5±0.7, 21.4±1.1 percent and lymphocyte: 73.5±1.4, 68.4±1.1 percent and eosinophil: 5±2.8, 7±1.2 percent and monocyte: 3.5±3.5, 3.2±0.8 percent. According to statistically study the count of lymphocyte had significant difference between male and female fish and this count in male was higher than female. (p≥0.05).

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Inland water aquaculture activity have been known as an important approach for protein production while reservoir lakes recognized to have a significant potential for this purpose. Zanjan province in Iran with several dam reservoirs is suitable for aquaculture development. This study was conducted on biotic and abiotic factors of two lakes Shovir and Mirzakhanlo in order to determine aquaculture potentially of reservoirs. This two lakes located on different climatic region; Shovir located in region of semi arid area with very cold weather in winter, while Mirzakhanlo is in semi humid area and warm weather characteristic. In this study the plankton, benthos and fishes were assessed and the 15 hydrochemical factors were measured in order to determine the fisheries potential for fish introduction or release. The results showed that the phytoplankton abundance of Mirzakhanlo varied between 1.6 to 45.2 million cell/l. with 32 identified genus. The zooplankton abundance varied between 48 to 632 n/l. and 22 identified genus. The abundance plankton in shovir varied between 1.350 to 34.2 million cell/l. and 240 to 4500 n/l. for phyto and zooplankton respectively. Macrobenthos biomass were 21.4 and 0.34 g/m2 in Shovir and Mirzakhanlo lakes respectively while Chironomidae and Tubificidae families were dominant groups. The lake sediment organic matter were 4.3 and 3.2 % respectively. In ichtiology survey identified 5 and 7 species in Mirzakhanlo and Shovir lakes respectively. The hydro-chemical results indicated no restriction for aquaculture activity and according to trophic model both lakes are recognized as meso-eutrophic and eutrophic. Despite of climatic restrictions, the potential for fish production was estimated about 321 and 151 kg/ha for Shovir and Mirzakhanlo lakes respectively that can be improved by using agricultural and the other native facilities.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study aimed to investigate the effects of 5- parameter dissolved oxygen, PH, nitrite, nitrate and temperature of the water on Streptococcosis incidence in two groups of fry and grower fish. Research was performed at west Mazandaran province -Tonkabon region in 12 rainbow trout selected farms. Research conducted in 3 farms with well source water , 8 farms with water source of the river of Dohezar and one farm with water source of the river of Azarood, during 12 consecutive months.From 1390/04/01 to 1391/04/01, once time each month , and in each time 10 fish randomly sampled, inlet water were sampled simultaneously. Of 1350 sampled fish 607 fish with an average weight 22.04 gr , average length 12.59 cm were in fry category and 743 fish with an average weight 156.25 gr, average length 23.32 cm in were grower category. Streptococcosis observed only in grower category. Of 72 fish with clinical signs of the disease, 14 numbers were positive Streptococcosis (19.44%) and 58 numbers were negative Streptococcosis(80.55%). Three fish from grower category has not any clinical signs of disease and seemed to be healthy but were positive Streptococcosis in examinations (0.22% of total fish sampled. Fish with clinical signs of the disease but negative Streptococcosis were of at least 55.1 gr and at most weight 417 gr respectively. The results showed that 47.07% cases of Streptococcosis happened at 15.6 °C water temperature, 35.29% at 16.98 °C and 17.64% cases happened at 18.04 °C so that 100% of Streptococcosis cases was observed at the average temperature of 16.99 °C. In addition, the survey results show that despite relatively high levels of nitrite in source water of farms from wells, nitrite does not effect on the disease incidence. It seems that an optimal level of dissolved oxygen in water is effective in reducing the effectiveness of nitrite in this disease. According to equation coefficients logit model is as follows: According to Logit model, it seems that for every degree change in temperature and pH of water, morbidity change will diminish 0.37 % and 1.74 % respectively. 80.56% of fish sampled that had the clinical symptoms, was ranging from an average weight of 5.1 gr (fry) and 417 gr (grower fish), that despite having clinical signs of the disease were negative Streptococcosis. Isolation of Staphylococcus bacteria as well as Gram-negative bacilli from fish with clinical symptoms similar to the symptoms of Streptococcosis, may indicate the involvement of other pathogens in fish clinical signs.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The national research plan with title of "Study on health status of Iran Coldwater hatchery and rearing farms" was done in order to identification and tracking of main causative agents of recent mortality in Iran Coldwater hatchery and rearing farms and recognize of infected zones and design of landscape distribution of Epizootic Coldwater fish diseases in the country. This plan was conducted parallel and in same time in some polar provinces of Coldwater fish production such as Mazandaran, Gilan, Ardebil, West Azerbaijan, East Azerbaijan and Kurdistan in three years from 2006-2008. In this regard, about 23,21 and 20 farms in Mazandaran province, 30 farms in West and East Azerbaijan and Kurdistan provinces and 19 farms in Gilan and Ardebil were selected as randomly and tracking were done yearly from 2006-2008. This research was conducted according to regular planning consists of farms visit that was done according to statistical plan and completion of Questionnaires and sampling. The findings in Mazandaran province revealed that fish infections background and infectious diseases were increased in period of 2006-2008. In fact, 56% of all fish farms in 2006, 71% in 2007 and 85% in 2008 were recorded as infected farms. In other side, average weight of fish final products was more 500gr in consume market. So, regarding to long period of fish culture in mentioned fish occurrence of more morbidity could be expected. The streptococcus infections were most important fish bacterial diseases that have more incidence and pathogenicity in collected questionnaires. Also it revealed more occurrences in summer season in above 15oC temperature in affected fish farms. Also, Enteric Redmouth Disease (ERM) and Saprolegniasis were reported as second and third degree in examined farms. Meanwhile, findings of control, prevention and treatment of our survey revealed that using of antibiotics and detergent materials were increased in mentioned province. Indeed, 34.7% of all fish farms in 2006, 71.4% in 2007 and 75% in 2008 have applied treatment operation and using of detergent materials in affected farms. In other side, frequent using of Erythromycin antibiotic was reported several times in 2008 so fish farmer faced to Bacterial resistance and should be using from Florfenicol as alternative antibacterial. Also, in feed sampling from all fish farms about 3 fish farms in 2006 and 5 fish farms in 2008 were faced with food poisoning that originated from high TVN and peroxidase in fish food consumed. These farms revealed mass mortality that stopped after change feeding regime. In conclusion absence of fish health management could be considered as main agent of mentioned mortality in Mazandaran province. The findings of our survey in West and East Azerbaijan and Kurdistan revealed that absence of sufficient experiences in fish farmers and their neglect from water quality concepts, farm cleanness, using of suitable detergent materials for fish ponds and instruments and disability in continuous monitoring of physic-chemical factors of consumed water could be considered as most important problems. So, fish morbidity and mortality, growth decrement and low production rate were expected. Unfortunately, despite the occurrence of infectious and non- infectious diseases in examined fish farms, there were no documents and information about diseases history, clinical signs in dead fish, feeding regime, fish mortality (rate of daily mortality, age and weight of moribund fish), treatment operation, drugs usage, growth rate, physico-chemical factors and fish density. So planning for control and prevention of mentioned diseases were unsuccessful in affected fish farms. Also, occurrence of some epizootic fish viral diseases such as VHS, IPN and IHN were observed frequently with mass mortality about 40100% in some examined fish farms that produced some tragic economic lost in the mentioned provinces. Similarly, some bacterial, fungal and parasitic diseases were observed repeatedly in some inspected farms such as Flavobacterium, streptococcus infections. Also, some unknown causative agents in parasitic diseases were observed several times such as Dactylogyrus, Gyrodactylus, Ichthyophthirius multifiliis, Trichodina, Chilodonella, Diplostomum and fungal diseases such as Saprolegniasis. In conclusion it seems that absence of fish health management, inadequate rate of hygienic technical services, absence of quarantine programs for transfer of new eyed-eggs, juvenile and live broodstocks packages without health certificates from authorized organizations, uncontrolled entry of foreign eyed-eggs (France, Denmark, Australia and Armenia) and neglect in using of suitable detergent materials for fish ponds, instruments, consumed water and infected eggs, not screening of broodstocks in hatcheries could be considered as most important causative agents in occurrence of infectious diseases and main problems in affected farms in mentioned provinces. Similarly, our findings in Gilan and Ardebil provinces revealed that their problems were similar to other provinces. In fact, neglect in establish of necessary Infrastructures in fish farms and dereliction in health management concepts could be considered as main reasons of occurrence of fish infectious and non-infectious diseases in studied fish farms in mentioned provinces. In fact, often fish farms visited hadn't suitable structures without control and prevention approach. There were not observed detergent using, quarantine programs and prevention methods. Entrance of unknown persons, birds and wild animals were ordinary in mentioned farms. Unfortunately level of farmer’s knowledge was low and no training courses and extension programs were planned by authorized organizations. Meanwhile, food storages were unsuitable and food packages were stored in inappropriate situation so poisoning conditions were increased in examined farms. In conclusion it could be finalized that Coldwater fish farms in Gilan and Ardebil provinces situated in insufficient position and correction of current situation are needed urgently. In final elicitation, it would be mentioned that lack of basic infrastructures could be introduced as most important reasonfor spread of diseases, mortality and related economic losses in studied provinces. Therefore, attention to environmental affairs and access to Sustainable Development are recommended. Also consideration of biosecurity regulations and health management concepts would be important requirements for modification and reformation of Coldwater fish farms in examined provinces towards A Better Tomorrow.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The marine survey for sturgeon stock assessment was conducted in summer, winter and spring in the years 2006 and 2009 to estimate the relative and absolute abundance and percentage composition of each species in the Guilan, Mazandaran and Golestan Provinces. This survey was carried out in the Iranian waters of the Caspian Sea on board the Sisara2 and Guilan vessels using trawl nets at 2-100 m depths. Trawling was carried out in 85 stations that were selected using a stratified random design. The number of stations in each scope was based on the area of the scope in terms of the total area. Trawling and sampling in shallow water up to 10 m were carried out using 9 m trawl nets whereas 24.7 m trawl nets were used for depths more than 10 m. Trawl surveys were carried out in the daytime. Trawling velocity was kept at 2.5-3 kts and trawls lasted half an hour in order to calculate abundance, and biomass of sturgeons using the swept area method. Catch per unit area (CPUA) in the winter 2006 survey was 3853 specimens nm2 , in the summer and winter 2007 survey was 1854 , 2912 specimens nm2 at depths less than 10 m respectively . CPUA for sturgeons in spring 2008 survey was 2103 specimens nm2 at depths less than 10 m and 393 specimens nm2 at depths greater than 10 m (10-100 m depth). These values in the winter 2008 survey dropped to 44 specimens nm2 at depths at depths above 10 m. CPUA for sturgeons in the spring 2009 survey was 300 specimens nm2 at depths less than 10 m and 307 specimens nm2 at depths greater than 10 m. In all the surveys conducted CPUA for A. persicus was higher than that for the other sturgeon species. Based on the calculations carried out in the marine survey in winter 2006 the estimated absolute abundance for sturgeons was about 2977.363 thousand. The total biomass of sturgeon was estimated as 131.713 tons. In the summer 2007 survey total abundance was estimated 1432.398 thousand, and total biomass of sturgeons was estimated at about 312.161 tons. In the winter 2007 survey total abundance for sturgeons was estimated at about 2250.105 thousand, and total biomass was estimated 578.08 tons. In the spring 2008 survey total abundance was estimated at about 3002.832 thousand. The total biomass was estimated at about 2533.318 tons .In the winter 2008 survey total abundance was estimated at about 152.722 thousand, and total biomass in winter 2008 was estimated 170.540 tons. Total abundance in spring 2009 survey was 1310.232 thousand and total biomass was estimated at 2019.tons. Investigation of stomach content of sturgeon Acipenser persicus caught under 10m depth in 2006 to 2007 surveys showed that there is significant difference in the consumed food. Polychaeta is the major food consumed and crustacean an the minor one(P〉0.05).Also no new types of food( such as bony fishes or benthic) have been observed in food chain of Acipenser persicus only the food consumption rate has been related to the season of year and increases or decreases in warm or cold seasons, respectively For physiological study and determination of sexual maturation stages in sturgeon,119 gonad sampling prepared. The results showed that 63 % of fishes were females and 37 % of them were males. Gill microscopic study shows complications such as hyperplasia, curvature, adhesion, embowed, shorting and lengthen of secondary filaments and fraught bloody. Microscopic study on liver indicates signs of cloudy inflammation, fatty degeneration, dispersion of billed secretions and cell atrophy. The population genetic structure of Persian sturgeon (Acipenser persicus) in Sefidrood and Gorganrood rivers watershed analyzed based on microsatellite markers during sturgeons assessment in 2006-2008. Results showed that Acipenser persicus in two region of south part of Caspian Sea are two independent populations.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Rregarding the potential and capabilities of different socio-economic, ecological and recreational, Hurolazim wetland is allocated as a special place in the collection of ecosystems and environment and the study of existing ecological conditions is necessary to protect and restoring management. In this study, monthly Samples of four stations (stations north of the road , Imam Reza (1) and south of the road, Imam Reza (2) ,in the Rofayeh area and stations Tabor (3) and the Shatt Ali (4), in the Shatt Ali area) were taken during the year from April to March 2012. Samples included physical and chemical parameters , phyto and zoo planktons, benthos, fish, and fishing status. Phytoplankton samples using sampling bottles from 0.5 meters below the surface were taken and counted based on alive unit. Zooplankton samples were collected by 100 micron mesh size plankton net from a depth of 1.5-2 meters . Benthic animals and sediment were sampled by Van Vin grab(0.125 square meters). One sample for benthos and one sample for grain size analysis and percentage of organic matter were sampled from each stations. In order to estimate the monthly depleted catches, data collected from the census in place and sampling was done at the time. Three fishing area has inspected randomly once every 15 days and active fishermen and caches were recorded in the prepared forms during the day. In this way, the number of observed boats, the average boat per day, the catches of the boats and CPUE were registered and total fishing effort was calculated monthly. In this study, 194 species of phytoplankton were identified. Diatoms with 85 species, Cyanophyta with 59 species, Chlorophyta with 31 species, Euglenophyta and Dinophyta with 18 and one species were observed respectively. The highest abundance frequency of phytoplanktons with 38.96 percent were observed in Tabar station (3), Diatoms with 46% has shown the highest frequency and then Cyanophyta (34.17%), Chlorophyta (16.39%), Euglenophyta (1.6 %) and Dinophta (1.58%) were included of the total abundance respectively. In the summer colonies of Cyanophyta were in high density. A total of 35 species of zooplankton have been identified. from Rizopoda, the species of Arcellidae and Centripyxidae families, from Rotifera, the species of Brachionidae, Lecanidae, Asplanchnidae and Philodinidae families, from Cladocera ,the species of Daphnidae, Sisidae and Chydoridae families and from copepods, Cyclopoda families have been observed that included about 98 percent of identified zooplankton. Respectively, Copepoda (39.9 %), Rotifera (34.71 %), Cladocera (22.38 %) and Rizopoda (0.843 %) were dominant groups. The species Brachionus urceolaris with average density of 7.29 individual per liter, is the most abundant species that included 17 % of total abundance frequency in the wetland. The higher frequency of crustacean zooplankton such as Copepoda and Cladocera could be indicated an environment more favorable conditions and expected to be good status of food in the Horolazim wetland. Among the known benthic groups, families, Tephritidae (85%) and Chironomidae (7 %) of the order Diptera and Ostracoda (2 %) from crustacean, were the dominant macrobentic groups Among the studied stations, Station South Road Imam Reza (2), and the station Shatt Ali (4), were the highest and the lowest abundance respectively. The mean abundance of macrobenthos in different seasons showed the lowest and the highest abundance frequency in summer and winter respectively. According to diversity indices, The stations Tabar (3) was the highest and the Station South Road Imam Reza (2), was the lowest value of diversity index. The results showed the higher than 71.84 % of Silt-Clay percentage in all stations, The highest value of sediments TOM in the Station South of the Road Imam Reza(2) in the winter and the lowest in station Shat Ali(4) in summer were recorded. Based on HFBI index the stations north of the road Imam Reza (1) and the station Shatt Ali (4) in moderate status and the stations south of the road Imam Reza (2) and Tabar (3) in good status were classified. In this study, 15 species of fishes belonging to 8 genera and 3 families were identified. It was noticed that 87.4 percent of all identified species in the wetland belonged to the Cyprinidae family. The results of previous studies in 2006 and 2008 in the Iraqi part of Hawizeh wetland showed that the most common fish species belonged to Biah, Karas, Hemry and Shelej that included 89.3 percent of total fishing in the current study .Finally, It is evaluated that changes in water regime of freshwater wetlands, controlled the environmental characteristics and conditions. That means water plays a decisive role in the vital characteristics of wetlands. changes of quantity and quality of water may be associated with changing the quantity and quality of biotic fauna in wetland system. In the management and protection of a wetland system, it is necessary to adopt measures based on scientific principles and reasonable methods in order to protect water quality.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The Goal of project implementation was survey of biological roles of Northern pike, Esox lucius, in decreasing of Coarse fish and other un economics organisms in carps ponds and also increasing of final crops in hectare and determination of Suitable ration of pike in ponds. This project implemented by 5 treatment with 3 replicates for every ones in 2 years . The pike density was 200, 350, 500 and 650 fish individuals per hectare for 1 , 2 , 3 and 4 treatment , Respectively, and fifth treatment was without pike. The treatments of 1 and 3 conducted in first year and other in second year of test period. At first, about 26 brooders Caught from Anzali Lagoon, and reproduced by artificial and semi - natural methoods in Sefidroud Pisheries Research Station in 12–14 °c temperature. Produced larvae reared in earthen ponds and fries reached to weight of 10 -12 g after 45 days. Mean weight, length and survival rates of fish was 12.27 and 32.5 g , 11.44 and 15.83 cm , and 40 and 21% after 45 and 60 days , respectively . The carp density in ponds was 3500 fish individualsper hectar and stocking rates were 55 % silver carp, 20 % common carp , 10 % bighead carp and 15 % grass carp . In throughout of the experiment period, physico – chemical factors measured and plankton ( phyto and zoo) , benthos , un wanted fish and other organisms investigated . The biomass of unwanted fishes reduced to 76/81 and 60/6 % in first and second year of experiments respectively. The results showed that Esox lucius had effect in increasing of objective fish produce about 17.9 % and 3.9 % in first and second period of project implementation respectively . The average of fish produce in pond unit ( 2400 m2 )was 842 kg ( 3508 kg/ha ), 825 kg ( 3439 kg/ha ) and 776 kg ( 3232 kg/ha ) in first , second and control treatments first year of test period , and also in second year was 865 kg ( 3603 kg/ha ), 877 kg ( 3652 kg/ha) and 848 kg ( 3531 kg/ha) in second , fourth and control treatments , respectively . A significant different found in final weight mean of common carp between treatments and Control ponds (P 〈0/05), as the weight of common carp in treatments ponds was 220 % in first year and 191 % in second year more than control pond. In end of the trial, the mean weight of Esox lucius was 265 ± 74, 276 ± 104, 159 ± 33 and 265 ± 89 g in 1, 2, 3 and 4 treatment, respectively. Survival rate of Northern pike in 1 to 4 treatment was 43.8, 55.2, 40 and 35.6 %, respectively.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Blackmouth croackers (Atrobucca nibe) resources are the most important commercial stocks in the north-west of Oman Sea, exploited as lantern fisheries by catch with trawlers vessel. At least 50 specimens were sampled monthly from September 2012 to July 2014. Results showed blackmouth croacker have several small peak in gonado-somatic index, but the most frequency of adults occurred in May. The female: male ratio was calculated 1:0.8 and the LM50 was estimated at 35 cm. The mean of absolute and relative fecundity were estimated 92988 and 223 respectively. LM50 and LC50 were calculated and the results showed this species mainly caught before length of maturity, and the mass populations have not sufficient opportunity to reproduction. The mean of egg diameter for black mouth croaker were calculated at 533±103. Linear model of Fecundity= 9597.6TL-233880 was calculated for length-fecundity relationship . Results of feeding showed lantern fishes (65%), shrimps (11%), Japanese threadfin bream (13%) and the other fishes (11%) were the main feeding regime of black mouth croaker. This species was carnivore, the food prefect mainly consisted of lantern fishes (57.7%) and shrimps (28.2%). The vacuity index (87.7 %) indicated this spices was low appetite fish. Total length range was 18 to 47.5 cm with mean length of 28.7 cm, and the class of 23-24 cm was the most frequent length in fishing ground. The length-weight relationships in A. nibe were calculated for female and male W= 0.0121L2.9385 and W= 0.0075L3.0737 respectively, both have isometric growth. Growth parameters of L∞ and K were estimated 50 cm and 0.2 y-1 respectively. Parameters of t0, Tmax and Ǿ were calculated -0.7 year, 14 year and 2.69 respectively. This species have two recruitment period, and the peak of recruitment was occurred in May with 23.14 percent. Total mortality , natural mortality and fishing mortality rates were calculated 0.53 y-1, 0.46 y-1 and 0.07 y-1 respectively. Due to the calculated exploitation rate (0.13), it is appreciated the improvement of black-mouth croaker in the Oman Sea. Base on seasonal and monthly CPUE it was resulted the peak of fishing density were occurred in the winter. Results showed the main distribution of black-mouth croaker concentrated on the continental slope in 200 m depth, but these stocks move to deeper waters ( more than 200m) in warm season and extend to shallow waters (less than 200m) in winter.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The project of survey on health status of ornamental fishes in Mazenderan , Golestan and Khorasan Razavi carried out with association of 5 , 2 and 6 centers in orderly. The main aims of this survey were identification and distribution local infectious of epizootic diseases , identification positive and negative points, offers management applicable guidelines to prevents of diseases.The results of survey showed that important virologically agent identified was Lymphocystis virus in Angel fish. Also, main bacteriologically agents were Aeromonas spp, Pseudomonas spp and vibrio. As well as, from the fungal agents that were identified can mentioned to Aspergilus flavus , Mucor , Penicilium and Alternaria. The important parasitic agents also were Trichodina , Ichthyophytrius , tetrahymena , Dactylogyrus, Gyrodactylus and capillaria. In the health management part of this survey positive points include non application of antibiotic and cooperative of hatchery directors with executive organizations to sampling examination periodically. The negative points were non familiarity and training about fish disease, werenot technical director, prepairing feeds without familiarity with principals of diets, non quarantine units before fishes entrance to production cycles, non existens good food storage rooms, non existens foot bath in entrance gate to the hatchery systems and ets.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Sampling for this study was carried out at the freshwater crayfish fishing season (May to December ) from the selected packs made from one of the harvesting centers at the first day ( harvesting and packing ) until the seventh day ( the export time ) using registered number to determine the handling effect ( live ) and changes in chemical and microbial indices in tail fillet stored at -18 ° C at days 1 and every 15 days considering 1 treatment and 3 replicates. The comparison of results mean (±SE) of the effects of handling on tested indices showed a significant reduction of protein percentage (dry weight) of tail filet at day 7 (13/85 ± 0/07) comparing with fishing day (16/1 ± 0/05) ( (p 〈 0.05). So that by increasing the handling and storage period, the amount of protein (dry weight) was reduced. Comparison of carbohydrate percent (dry weight) during handling showed a significant difference between the first day (2/8 ± 0/009) with the seventh day (0/9 ± 0/005 (p 〈0.05). Percent of moisture showed a significant increase during handling between day 1 (79/2 ± 0/24) and 7 (84 ± 0.41) (p 〈 0.05). Mean chemical composition of haemolymph showed a significant reduction in triglycerides (milligrams per deciliter) at fishing day (14/3 ± 0/16) and day 7 (11/7 ± 0/13) (p 〈 0.05). Comparison the means of saturated and unsaturated fatty acid profiles and the ratio of DHA / EPA did not show significant differences (p〉0.05). Comparison of the mean (±SE) of total bacterial count (log CFU / g) and psychrophilic bacteria at different periods of tail fillet storage at - 18 °C showed significant differences at day1 ( 3.48 ± 0.00 and 1.0± 0.00) compared to day 180 ( 6.86± 0.85 and 6.75± 0.25) , respectively(p〉0.05) .Comparison of Mean (±SE) of chemical indices for first day with day 180 were thiobarbituric acid ( mg malondialdehyde /kg ) (0.19/0 ± 0/07) and (1/45 ± 0/25), peroxide ( meq oxygen/ kg fat ) (0/81 ± 0/21) and (2/2 ± 0/3), total volatile basic nitrogen ( mg per 100 g fillet ) (13/21 ± 1/01) and (26/6 ± 1 / 40) and acidity (6/26 ± 0/08) and (6/55 ± 0/05), respectively which showed significant differences with each other (p 〈 0.05). Therefore, cited to the results of microbiological and chemical parameters, maximum shelf life longetivity of freshwater crayfish tail fillets packaged in the air is recommended as 5 months after freezing at – 18 °C.

Description: Iranian Fisheries Science Research Institute

Description: Published