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  • 1
    Publication Date: 2021-05-19
    Description: Neogobius caspius is an endemic fish species in the Caspian Sea belonging to the family Gobiidae that ecologically play important role as a predator fish in the food chain .The main objective of this research was determination of some reproductive properties of N. caspius in the southwest coasts of the Caspian Sea. Sampling was carried out with a bottom trawler in three stations (Astara, Anzali and Chabuksar) from October 2004 until September 2005. The species was identified based on meristic parameters. The maximum gonadosomatic index (GSI) was recorded at 7.52% for male and 100.12% for female fish in June. A sharp decrease in GSI value from June to the end of September in both sexes was observed and we found that the spawning of the species takes place several times each year. Hence, the species is considered a late spawner. Female to male sex ratio was 1.47:1. Absolute fecundity was in the range 212-1234 eggs and the relative fecundity fluctuated between 18.73 and 29.89 eggs per each gram of the body weight. The correlation between absolute and relative fecundity with age was positive and with total length and full weight was negative. Egg diameter was in the range 0.06 to 0.23mm. The correlation between egg diameter, age and total length was positive.
    Description: Published
    Keywords: Food chains ; Endemic species ; Brackishwater fish ; Neogobius ; Gobiidae ; Neogobius caspius ; Brackish ; Biological surveys ; Sex ratio ; Males ; Gonadosomatic index ; Fecundity ; Fish physiology ; Reproductive cycle ; Body size ; Reproduction ; Females
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.87-98
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  • 2
    Publication Date: 2021-05-19
    Description: ABSTRACT (UNDETERMINED) Pike (Esox lucius) of Chamkhaleh River in Langrood (Iran) was studied from winter 2003 to autumn 2004. We collected 123 specimens of the fish and sent them live to the lab for examinations. Biometrical measurements, age and sex determination were conducted on the samples. The eye, skin, gill, digestive system, muscle and other organs of the specimens were examined for parasite infestation. Seven parasites: Raphidascaris acus, Camallanus lacustris, Diplostomum spathaceum, Tetraonchus monenteron, Triaenophorus crassus, Corynosoma strumosoum, Lernaea sp. were found in the pikes of the Chamkhaleh River. The most prevalent parasite was R. acus (37.39%) and the least were C. strumosum and Lernaea sp. (0.81% each). The highest mean intensity of the parasites was related to T. crassus (8.45 specimens) and the lowest was detected for Lernaea sp. (0.01). The highest range in parasite infection was seen for R. acus (1-45) and the lowest for Lernaea sp. with only one individual parasite. We observed seasonal, age and sex differences in infection rate with the parasites. This is the first time report of the pike as a host for C. strumosum.
    Description: Published
    Keywords: Tetraonchus monenteron ; Raphidascaris acus ; Diplostomum spathaceum ; Esox lucius ; Camallanus lacustris ; Corynosoma strumosoum ; Triaenophorus crassus ; Age ; Skin ; Freshwater fish ; Digestive system ; Gills ; Freshwater ; Sex determination ; Eyes ; Muscles
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.37-50
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  • 3
    Publication Date: 2021-05-19
    Description: Samplings were carried out weekly in coastal waters of the Guilan province (Caspian Sea) by a hand net with 0.5mm mesh size during 1996-1997. The results of one year sampling showed that the mean total length(T.L.) of this shrimp (pooled data of females and males) was 28.58±5.58mm (x±SD), and were 26.46±4.30 and 30.01±6.30mm in males and females, respectively. For ovigorus females, mean T.L was 36.16±3.13mm, also the minimum and maximum T.L of the males were 12.6 and 41.1mm, respectively. In females these figures were found 10.7 and 43.4mm, respectively. The length-weight relationship for the males and females were determined as W=0.0002 TL2.97 (R2=92.13) and W=0.00002 TL2.98 (R2=92.84), respectively. Spawning season was determined from May to September. The average absolute fecundity was 796±320, with a range of 360 and 1660. There is a direct retationship between fecundity and T.L. Females provided 59.42% and males 40.56% of the population, the sex ratio deviated from 1:1 (P〈0.05). The growth coefficient of Loa for females, males and pooled data based on powell-wetheral methods were 42.6, 34.4 and 42.5, respectively. The growth coefficient of K based on Shepherd method were 2.1, 2.3 and 2.5 for females, males and pooled data, respectively. Natural mortality rate (M) calculated as 2.29, 2.29 and 2.28 per year for females, males and pooled da1a, respectively. Total mortality rate was calculated as 2.38, 2.50 and 2.61 per year for females, males and pooled data, respectively.
    Description: Published
    Keywords: Population dynamics ; Growth ; Mortality ; Spawning ; Palaemon elegans ; Sampling ; Length ; Shrimp ; Females ; Males ; Fecundity ; Growth
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.109-126
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  • 4
    Publication Date: 2021-05-19
    Description: Morphological features of Golden mullet (Liza aurata) population in the southern coasts of the Caspian Sea were studied. A total of 228 fish specimens were collected from Bandar Anzali, Kiashahr, Babolsar and Bandar Turkman in Iranian waters. A combination of Truss network, traditional system and few meristic counts were simultaneously applied to the sample set. Statistically high significant morphometric differences were observed between the four L. aurata stocks. Univariate analysis of variance (ANOVA) revealed significant differences between the means of samples for 10 out of 25 standardized morphometric measurements of truss system, 3 out of 7 measurements of traditional morphometric system and also the number of second dorsal fin spines, soft rays of second dorsal fin, total number of pectoral fin rays, soft rays of anal fin, number of squmosum scales and pyloric caeca among meristic counts. Discriminant analysis correctly classified 76% and 70.3% of individuals into their original samples for morphometric features and meristic counts, respectively. Plotting discriminant functions revealed differentiation of the four stocks based on morphometric measurements. The Bandar Anzali stock was isolated from the others, and the Baholsar stock was found to be located between Kiashahr and Bandar Turkman stocks. The pattern of morphological discreetness suggests a direct relationship between the extent of morphological divergence and geographical separation.
    Description: Published
    Keywords: Pyloric caeca ; Meristic counts ; Fin ray counts ; Liza aurata ; Brackish ; Animal morphology ; Population genetics ; Geographical distribution ; Morphometry ; Mullet fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.35-48
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  • 5
    Publication Date: 2021-05-19
    Description: The toxic effects of the oil products Phenol and 1-Naftol on fingerlings of the Persian sturgeon were studied in 2003. We carried out five treatments with three replicates and one control for each of the chemicals using the static O.E.C.D. method in 20 liter aquariums each containing 10 fingerlings. During the experiments, the average pH was recorded as 7.2, total hardness was measured to be 194 mg/l, average water temperature was 25.1 degrees centigrade and dissolved oxygen was 7.2 mg/l. Using the Probit Analysis procedure, we found that the LC50 96h of the Phenol and 1-Naftol for fingerlings of the Persian sturgeon was 36.65 and 1.32 mg/l respectively. We determined the maximum allowable concentration of the Phenol and 1-Naftol for the fingerlings of the Persian sturgeon to be 3.66 and 0.13 mg/l respectively.
    Description: Published
    Keywords: Chemical ; Lethal ; Phenol ; 1-Naftol ; Acipenser persicus ; Fingerlings ; Persian sturgeon ; pH ; Temperature ; Dissolved oxygen
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.147-160
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  • 6
    Publication Date: 2021-05-19
    Description: Considering the reduction of valuable commercial fish in Anzali lagoon during last decades and presence of the silver crucian carp with high frequency; the research project or 'Biological aspects and population dynamics or Carassius auratus" was designed. The study area was stratified to four regions (Abknar, Siah-keshim, Markazi and Sheyjan). Sampling were carried out bi-weekly by using electro-shocker. The mean fork length and mean weight for both sexes were measured 19.5±5.8 cm, and 196.8±137.4 g respectively. Also, the mean age was estimated 2.6±1.3 years (n=750) and minimum and maximum fork length were measured 2.5 and 31.5 cm respectively. The mean length, weight and the age of silver crucian carp in Siah-keshim region were higher than the other regions. The spawning season of this species was found from May to June. The results showed a sex ratio of F:M=99.3:0.7. Some calculated population parameters were as follows: exploitation rate = 0.47, L∞ = 36.0 cm and K = 0.23 per year.
    Description: Published
    Keywords: Biological ; Commercial ; Population ; Carassius auratus gibelio ; Fish ; Silver crucian carp ; Carassius auratus ; Sampling ; Length ; Age ; Weight ; Spawning ; Species ; Sex ratio
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.57-70
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  • 7
    Publication Date: 2021-05-19
    Description: This research project was carried out in Gulian Fisheries Research Center in 1998. For this purpose, two ponds were selected: Pond No. 1 with 450m2 area and pond No.2 with 250m2 area and then 3500 pieces/hectar of hybrids with 5-7g weight were added to the ponds. In order to determine their main food, they were fed by pelletes and grass according to their mean weight. Meanwhile, by adding mineral and organic fertilizers to the water, a suitable media including phytoplanktons, zooplanktons and benthoses were prepared for feeding of fishes. The stomach contents observations of 160 specimen of hybrids showed that this hybrid is a herbivorous fish and macrophytes were their main diet; and phytoplanktons could be considered as the secondary random food.
    Description: Published
    Keywords: Rutilus frisii kutum ; Grass Carp ; Hybrid ; Diet ; Fisheries ; Weight ; Fertilizer ; Phytoplanktons ; Zooplanktons ; Benthoses ; Specimens
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.31-42
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  • 8
    Publication Date: 2021-05-19
    Description: In this study we used Daphnia magna as an index organism for ecotoxicological studies. In order to determine the filtration and ingestion rates in Daphnia magna, we used algea Chlorella volgaris (10 mg/1). Prior to the tests, the acute toxicity of the herbicides Machete and Saturn and the pesticides Diazinon and Malathion, in order to calculate their EC50, were determined. The concentrations which caused the same mortality rate in 24 hours as the EC50 concentrations of these chemical did, were 18.49 mg/1 for Machete, 4.46mg/1 for Saturn, 0.31 gr/1 for Diazinon and 1.5 grit for Malathion. In order to study the toxic effect of Machete, Saturn, Diazinon and Malathion on the filtration and ingestion rates, Daphnia magna was exposed to Ec50, 3/4 Ec50 ,1/2 Ec50 and 1/4 Ec50 concentrations. The rates were reduced after the organism had been exposed to these toxic chemicals for 5 hours. The effective concentrations at which feeding rate were reduced by 50%, compared to the controls, were for herbicides activity and pesticides action. These values in regard to filtration and ingestion rates were 2.8 and 3.3 mg/1 for Machete, 1.45 and 1.6 mg/1 for Saturn, 0.16 and 0.075 mg/1 for Diazinon and 0.6 and 0.7 mg/1 for Malathion respectively.
    Description: Published
    Keywords: Daphnia magna ; EC50 ; Diazinon ; Ecotoxicological ; Filtration ; Concentration ; Feeding ; Chemical
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.23-34
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  • 9
    Publication Date: 2021-05-19
    Description: The toxicity of the pesticides, Malathion and Diazinon, and the herbicides, Machete and Saturn, on mortality of fingerling of Rutilus frisii kutum were examined. Lc10 values for Diazinon, Malathion, Machete and Saturn were 0.14 - 0.24, 0.10 - 0.35, 0.14 - 0.55, and 1.45 - 2.50 mg/L respectively. The result showed that Diazinon, Malathion and Machete have a highly toxic effect on fingerling of R. frisii kutum and the herbicide, Saturn, in comparison with other poisons was less toxic.
    Description: Published
    Keywords: Diazinon ; Malathion ; Machete ; Saturn ; Mortality ; Fingerling ; Rutilus frisii kutum ; Toxicity ; Pesticide ; Herbicide ; Fish
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.9-18
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  • 10
    Publication Date: 2021-05-19
    Description: The recirculation of inorganic nutrients orthophosphate and nitrate in relation with productivity in sturgeon rearing ponds was studied through two rearing periods at the Shahid Beheshti Hatchery. The first rearing period commenced on May 24, 1998 and ended on July 26, 1998 whereas the second rearing period commenced on May 16, 1999 and ended on June 26, 1999. Four earthen ponds with a surface area of 2 hectares each were used in this studied of which three ponds (number 25, 26 and 27) were considered experimental ponds and one pond (number 24) was used as the control. Results obtained in the first rearing period indicate that the fertilization program employed in this study was suitable to maintain the productivity of experimental ponds. Growth rates in fingerlings also indicate a rapid increase in growth during the first few weeks of rearing. However unfavorable conditions encountered at the end of the rearing period (increase in water temperature, decrease in dissolved oxygen concentrations, deterioration of water quality etc.,) lead to decrease in food consumption by fingerlings that ultimately resulted in decrease in growth and survival rate of fingerlings (survival rate 60 % in first year). On the basis of the results obtained in the first year, measures were taken to and increase the biomass of benthic organisms in the rearing ponds. The biomass of benthic organisms in experimental ponds increased from a maximum of 2.1 g m-2 in the first year to a maximum of 189 g mo in the second year. However despite the management policies employed to maintain productivity and meet the food requirements of A. persicus fingerlings, water scarcity that prevailed in the entire region lead to an increase in water temperature, decrease in dissolved oxygen concentrations, over growth of aquatic vegetation and thus survival rate of fingerlings dropped to less than 40 % in the second year. Results obtained from scientific studies reveal that increase in pond productivity does not depend on basic knowledge alone. Techniques involved in pond management that provide suitable conditions required for fish culture such as stock assessment* basic control of fish growth, proper utilization of food resources in ponds and fertilization etc., play a significant role in this regard.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Sturgeon culture ; Productivity ; Fertilization ; Live food ; Survival ; Nutrients
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 58pp.
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