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  • Artikel  (115)
  • Population  (63)
  • Zooplankton  (50)
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  • Tehran, Iran  (114)
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  • 1
    Publikationsdatum: 2021-05-19
    Beschreibung: 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.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Stock assessment ; Sturgeon ; Acipenser persicus ; Diet ; Gills ; Sex ; Microsatellite ; Population ; Genetic ; Survey ; Species ; Sampling ; Trawling ; CPUA ; A. persicus ; Biomass ; Polychaeta ; Maturation
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 154pp.
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  • 2
    Publikationsdatum: 2021-05-19
    Beschreibung: More than 20 viruses have been reported as pathogenic to shrimp.WSV has been found to be highly pathogenic not only to penaeid shrimps, but also to a wide range of hosts which include marine crabs , copepods, freshwater crabs and prawns. Main objective of this study was detection and identification of white spot virus from wild shrimp and crabs population on the coastal waters of Hormozgan Province.The samples were collected from three area seasonally include: coastal waters of Qeshm Island, Hengam Island and Jask. In this survey have been examined 1080 shrimp from each species of P.indicus, P.semisulcatus, P.merguiensis, Metapenaeus affinis and 1080 crabs (gill organs) by PCR and histopathological methods. Diagnostic kit for this survey have been prepared from Genesis Biotechnology CO.in Malaysia, so called "Single-Tube Nested PCR for WSSV". The analysis results revealed that all samples which examined from these area were free from WSV. Following PCR tests that were negative for all samples so no observed any damages of histology due to WSV on gills.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Biotechnology ; White Spot Disease ; Virus ; Penaeus ; PCR ; Histopathology ; Wild shrimps ; Crabs ; Pathogenic ; Marine ; Copepods ; Population ; P.indicus ; P.semisulcatus ; P.merguiensis ; Metapenaeus ; Genesis
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 43pp.
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  • 3
    Publikationsdatum: 2021-05-19
    Beschreibung: 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.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Physical ; Chemical ; Survey ; Ecological Characteristics‌ ; Samples ; Phytoplankton ; Zooplankton ; Planktons ; Benthose ; Fish ; CPUE
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 204pp.
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  • 4
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    Unbekannt
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25298 | 18721 | 2018-09-07 08:30:09 | 25298 | Iranian Fisheries Science Research Institute
    Publikationsdatum: 2021-07-16
    Beschreibung: 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 nm^2 , in the summer and winter 2007 survey was 1854 , 2912 specimens nm^2 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 nm^2 at depths at depths above 10 m. CPUA for sturgeons in the spring 2009 survey was 300 specimens nm^2 at depths less than 10 m and 307 specimens nm^2 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.
    Schlagwort(e): Fisheries ; Iran ; Caspian Sea ; Mazandaran Province ; Golestan Province ; Guilan Province ; Sefidrood River ; Gorganrood River ; Stock assessment ; Sturgeon ; Acipenser persicus ; Diet ; Gills ; Sex ; Microsatellite ; Population ; Genetic ; Survey ; Species ; Sampling ; Trawling ; CPUA ; A. persicus ; Biomass ; Polychaeta ; Maturation
    Repository-Name: AquaDocs
    Materialart: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 154
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  • 5
    Publikationsdatum: 2021-05-19
    Beschreibung: This study was carried out in continuation of previous studies on artificial reefs monitoring in Khozestan coastal waters. The main purpose was the zoo species composition on and around the artificial reefs. Sampling was done from May 2012 to April 2013, from 4 stations in artificial reefs area. Reef structures were sampled by scuba diving. Physical and chemical parameters were measured and water quality status was determined by using WQS index. Zooplankton and macrozooplankton communities were sampled by 100 and 300 micrometer mesh size nets respectively. Benthic animal's samples from sediments around of the reefs body were collected by Ekman grab. Sediment characters, TOM and grain size were analyzed by using ignition loss and size series sieves methods respectively. Secondary production of macrobenthic animals based on dominant species length classes was estimated. Ichthyological information recorded by diver (census and video recording) and Gargoor traps were used for fishing effort calculation .Except for nitrite parameter (p〈0.05) in different stations and silica parameters (p〈0.05) in different months, other parameters were not shown significant differences in studied stations and months. The mean of zooplankton density was (914±52) N/m3 and the Copepoda species were the most abundant group (235 ±10) N/m3.Anosim analysis showed no significant differences in reefs specie composition. Different Crustacean groups were included more than 82 percent of macrozooplanktons communities. Among macrozooplankons, the mean density of decapoda, branchiopoda and copepoda were 302, 296 and 191.5 N/m3 respectively. The mean density of macrobenthic animals was 418±90.26 N/m2 and mollusk, crustacean and polychaets were the most abundant benthic animals respectively. During the study period, total macrobenthos biomass 11.37 g-wet/m2 and its mean value 2.84 g -wet /m2, were estimated. Annual production for polychaets and crustacean groups 154g-wet/m2 and 182 g-wet/m2 were estimated respectively. Annual production of total macrobenthic animals was about 675 g-wet/m2/y. According to sediment analysis, the range of silt-clay (8.7-95.6)% and seasonal mean TOM (4.47-13.25)% were calculated in studied stations. According to attached organisms biomass (wet weight), Cnidarian Anthozoa class with (88)% was the most abundant and then sponge (10)%, Cnidarian Hydrozoan class and arthropoda each one with 1% were included total attached organisms. Due to high biomass of Anthozoa species the most abundant mean was observed in spring season. The Malacostraca group especially Crustacean (72)% was the main mobile animals on reef bodies and then Echinodermata (Ophiurida and marine Orchids) (18)%, Mollusca (Bivalves and Gastropods) (4)% and Polychaets (3)% were the main mobile organisms. The range of Shannon diversity index was (3.22-3.46) and (2.44-3.38) in studied stations and months respectively.Totaly in studied area, the number 15 fishes species were observed and Sparidae family with 3 species were the diverse fish family.The fish Hamour (Epinephelus coiodes,Seranidae) (87)% was presented in all studied months and stations. After Hamour the Neopomacentrue sindensis and Diplodus sargus Kotschyi were the most abundant fishes. The maximum and the minimum of hamour catch per unit effort were in reef B in spring and reef C in autumn respectively .Data comparing showed that except for nitrite the other physical and chemical parameters were observed in the same range by 2005-2007 study. According to obtained results, Zoo communities in different part of ecosystem showed greater diversity than to past years and in comparing to mudflat coastal waters in Khozestan waters, new ecosystem has been created in the region. High diversity of different animal groups that were disperses in water column in early phases of its life and need to settlement to substrate to continuing the life were observed in area. Attached animals plays an important role in biological and ecological characters in the coastal area.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Physical ; Chemical ; Ecological ; Biological ; Species ; Artificial reefs ; Sampling ; Zooplankton ; Fishing ; Macrozooplanktons ; Decapoda ; Branchiopoda ; Copepoda ; Polychaeta ; Sponge ; Anthozoa ; Mollusca ; Bivalves ; Gastropods
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 134pp.
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  • 6
    Publikationsdatum: 2021-05-19
    Beschreibung: The project “Stock Assessment of Zobaidy, Pampus argenteus, in the North of Persian Gulf” started in April 2003 and completed by the end of April 2006 as a cooperative research project to assess the valuable stock of zobaidy shared between Kuwait and Iran in the North of Persian Gulf. The main objectives were to investigate and determine the basic biological parameters, the standing biomass, seasonal abundance, and the impact of regional fishery activities. These studies are necessary to recommend practical management policies and measures for long-term sustainability of the zobaidy stock. The sampling of fisheries data (catch, effort, fish length distributions, and biological data) was started in May 2003 and ended December 2006. Monthly length frequencies data were collected from both the drift gill net and shrimp trawl fisheries. Age determination was based on otolith sectioning, polishing, etching, and staining method. The age groups ranged from 0 to 10 yrs but the dominant age groups were 1-3 years and the estimated parameters for both sexes were L∞ = 32.0-36.0 cm FL and K = 0.26-0.30 yr-1, females grow faster than males. Sea survey on board of two dhow boats was carried out using swept area method. Higher abundance was always obtained in Kuwait Bay rather than the other areas surveyed in Kuwait and Khuzestan waters. The total estimated stock biomass in the surveyed areas varied from 42 t in January 2004 to 2,633 t in November 2004, while the Iranian biomass varied from as low as 19 t in October 2005 to 295 t in November 2003. The data indicated that Ras Al-Gaid, Bubiyan Island is the main nursery area in Kuwait waters, while Lifah, Busaif, and Bahrakan are important nursery areas in the Khuzestan waters. Kuwait Bay and Khor Musa are considered important spawning grounds and should be protected. Yield per recruit analysis showed that higher yield could be gained with increasing fish effort, which is not recommended under the present status of high exploitation rate. In contrast, virtual population analysis indicated that future catches will reduce if the fishery continues with present level fishing effort. A reduction of 50% would be required to maintain the present level of catches as well as to enhance the stock biomass. Formulation of a joint advisory management committee would be advisable approach to manage and monitor the zobaidy stock in the region. This will need commitment from the three countries in the region for data collection on regular basis on length frequency, statistics, and biological data. Copepods with high occurence of 64% - 88% is considered as the main item in the Pomfret fish, while jelly fish and other decapods crustaceans are considered as minor items. Observation of pre- flexion stage larvae of pampus genus among the specimens collected from Khuzestan coast water could be considered as an evidence for the spawning of this fish in this region. The occurrence of pampus larvae in Khuzestan coast during the months of June to October has been reported for several times. Examination of 101 specimens (38 from Kuwait, 63 from Iran) for molecular survey does not show any significant differences between Kuwait and Iran water stocks for this fish, so it is possible to hypothesize a unit population for zobidy stock in Persian Gulf and Oman Sea as whole.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Biological ; Pampus argenteus ; Zobaidy ; Stock assessment ; Growth ; Food ; Molecular study ; Biomass ; Fishery ; Sampling ; Survey ; Population
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 146pp.
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  • 7
    Publikationsdatum: 2021-05-19
    Beschreibung: In order to study plankton population composition and species diversity in different regions of Aras rivers and the evident reservoir sampling was performed monthly from determined sampling sites from April 2007 to March 2008. Sampling was conducted in reservoir lake by a PVC pipe with 2.25 m length and 5 cm diameter by columnar method. Besides, in more dipper (〉5 m) sites, sampling conducted from bottom to surface with 1-m intervals (layer sampling) by a 2-liter Ruttner type sampler. In river due to water flow sampling was conducted by a scaled measure. Phytoplankton sampling was performed by 1-liter bottles. Zooplankton was sampled by filtering of 30 L through 55- micron plankton net. These samples were then transferred into bottles and sampling date and the name of station were attached on the bottles. Then, the samples were fixed immediately and transported to laboratory. It should be mentioned some physical parameters were determined in situ. Also, a 1liter and another 2-liter water were collected to determine chlorophyll a and chemical factors respectively. Samples were preserved in dark and cold place for a week. The upper layers (without phytoplankton) were removed and the lower layer (with phytoplankton) was sampled into 5-ml chambers. The enumeration and identification was performed by a Nikon TS100 inverted microscope with ×400 (Phytoplankton) and ×200 (Zooplankton) magnification according to Utermohl (1958) method. About 50 fields were enumerated for each sample. The comparison of physicochemical and biological factors with standard criterion indicated that the presence of a fertile plain, agricultural growth, drought and higher water demand in recent years, as well as, higher population density, the Nakhjavan city location and sewage water flows into the Aras reservoir, the lake is going to be an eutroph lake. Sampling of crayfish was performed from 5 sampling sites seasonally. Aras reservoir freshwater crayfish biomass was sampled in 1391, by putting 100 funnel-shaped nets. At each site one row nets composed of 20 nets were put by rocks, connecting robe and boat. Twenty four hours later, total freshwater cray fish was sampled (at least 300 crayfish was randomly sampled from each site). The samples were transported to laboratory and their sex, sex percentage, biometric characteristics including length, weight were recorded. Length and weight groups were estimated totally and for males and females in each season. The average total length and weight were 106.43 ± 7.94 mm and 35.81 ± 10.86 gr respectively which both are lower than West-Azarbaijan fisheries criterion. In this study only 18.99 percent contained a length higher than exporting level (120 mm). Yet, only 16.46 percent of harvesting had higher than 50 g (exporting level). With regard to data, freshwater shrimp (Astacus leptodactylus) in Aras dam reservoir stock has reduced. In general, male-female ratio was high. The comparison of growth equations confirms that males had higher weights than equal females. In recent years, the freshwater crayfish harvesting has been declined due to increased harvesting and over loading of nutrients into the lake.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Astacus leptodactylus ; Environmental conditions ; Plankton ; Population ; Species ; Diversity ; Sampling
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 111pp.
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  • 8
    Publikationsdatum: 2021-05-19
    Beschreibung: In order to limnological study of Bukan Dam reservoir, sampling was performed monthly from determined sampling sites from April 2013 to March 2014. Sampling was conducted in reservoir lake by a PVC pipe with 2.25 m length and 5 cm diameter by columnar method. Besides, in more dipper (〉5 m) sites, sampling conducted from bottom to surface with 1-m intervals (layer sampling) by a 2-liter Ruttner type sampler. In rivers due to water flow sampling was conducted by a scaled measure. Phytoplankton sampling was performed by 1-liter bottles. Zooplankton was sampled by filtering of 30 L through 55- micron plankton net. These samples were then transferred into bottles and sampling date and the name of station were attached on the bottles. Then, the samples were fixed immediately and transported to laboratory. It should be mentioned some physical parameters were determined in situ. Also, a 2-liter and another 1-liter water were collected to determine chlorophyll a and chemical factors respectively. Samples were preserved in dark and cold place for a week. The upper layers (without phytoplankton) were removed and the lower layer (with phytoplankton) was sampled into 5-ml chambers. The enumeration and identification was performed by a Nikon TS100 inverted microscope with ×400 (Phytoplankton) and ×200 (Zooplankton) magnification according to Utermohl (1958) method. About 50 fields were enumerated for each sample. The comparison of physicochemical and biological factors with standard criterion indicated that the presence of a fertile plain, agricultural growth, drought and higher water demand in recent years, as well as, higher population density, the Saghez city which is the main source of pollution in Bukan dam reservoir has caused that Bukan dam is in the transit state from mesotrophy to eutrophy. The results of the present study suggested that higher trophy in Bukan dam reservoir together with algal high density has negatively affected the Fish life and has reduced the stock in the lake. However, complementary studies should be performed prior to releasing. In this way the problems of other ecosystems should be prevented.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Limnological ; Plankton ; Eutrophication ; Phytoplankton ; Zooplankton
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 82pp.
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  • 9
    Publikationsdatum: 2021-05-19
    Beschreibung: Goals: Determine of barcode of DNA in green tiger prawn, Penaeus semisulcatus, in the Gen bank of the species. Material and methods: In these study 30 specimens of Penaeus semisulcatus from each region in the Persian Gulf and Sea of Oman were sampled and preserved in ethanol 96%. The total DNA was extracted, COI gene was first amplified and then sequenced for each species. Finally the collected data were analyzed with the specific phylogenetic software. Result and discussion: Molecular analysis revealed some degree of interpopulation differences within two areas. Also for population study molecular data of species Penaeus semisulcatus were analysed base on COI RFLP and 16SrRNA sequences respectively. The results indicated that COI gen is a good marker for shrimp species differentiation that would be helpful to protect shrimp species.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Genetic ; Molecular ; Population ; Cytochrome oxidized COI ; Penaeus semisulcatus
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 24pp.
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  • 10
    Publikationsdatum: 2021-05-19
    Beschreibung: Population dynamics parameters and exploitation ratio of Jinga Shrimp, Metapenaeus affinis were studied from Sep 2011 to Dec 2011 and data collected from two landing places (Hendijan and Lifee-Bosif). During the project, more than 2200 specimens of jinga shrimp were measured. The mean value of length for the male and female were calculated as 9.8±0.86, 10.24±1.18 and mean value of weight for the male and female was as 6.730±1.64, 8.14±2.90 respectively. The length-weight relation were calculated as TW=0.024TL2.24 (n=1084,R2=0.71) for males, TW=0.011TL2.80 (n=1081,R2= 0.81) for females also we found significant different level length-weight relation in P〈0.05. The growth parameters of von Bertalanffy equation were as, L∞: 14.73 and K: 1.1 and t0: -0.02. The estimated valve of total mortality, natural mortality, fishing mortality and exploitation ratio is Z: 4.35, M: 1.68, F: 2.67, E: 0.61 respectively. By using method analyses knife-edge selection, relative yield per recruitment (Y'/R) :0.014, relative biomass per recruitment, (B'/R) :0.085., Exploitation ratio maximum sustainable yield, Emax : 0.38; biological reference points for Jinga Shrimp stock was calculated. MSY and fmsy value was 600T and 46100day respectively. Result in this study showed exploitation ratio Jinga Shrimp stock is over fishing and decreases exploitation ratio proposed.
    Beschreibung: Iranian Fisheries Science Research Institute
    Beschreibung: Published
    Schlagwort(e): Biological ; Jinga Shrimp ; Population ; Dynamics ; Exploitation ; Tiger tooth Croaker ; Otolithes ruber ; Metapenaeus affinis ; Population ; Male ; Female ; Mortality ; Coastal waters
    Repository-Name: AquaDocs
    Materialart: Report , Refereed
    Format: 202pp.
    Standort Signatur Erwartet Verfügbarkeit
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