Iranian Scientific Fisheries Journal
Year:2009 | Volume:18 | Issue:1|Papers Count:21

The propagation of marine and cultured broodstocks of Fenneropenaeus indicus were compared in 2003 in the center for training and stock enhancement in Kolahi port south of Iran. We used a factorial design to assess relative fecundity, percent of fertilization and hatching, number of nauplii, time of hatch, growth and survival rate in zoae, mysis, and PL. We also measured total weight and length of PL12. In this investigation 30 marine and 30 cultured broodstocks in their second stage of maturation were used in three replications, each including 10 marine and 10 cultured broodstocks. Induction of maturation was performed by ablation of eye stalk. After one week, 3 marine and 3 cultured broodstocks which were in their fourth stage of maturation were selected from each replication and were transferred to the spawning tanks. The offspring of each broodstock was reared separately till PL12 and the mentioned parameters were measured for each broodstock. Dunkan's mean test showed that the marine broodstocks produced napplii more than the cultured broodstocks and the weight of the post, larvae produced. By marine broodstocks was more than that of the cultured broodstocks (P<0.05). However, cultured broodstocks had higher relative fecundity and growth rate in mysis and PL than marine broodstocks (P<0.05). The marine broodstocks were better than cultured broodstocks for some of the quantitative parameters, but there was no significant difference between the stocks in terms of the qualitative parameters.

In this investigation, nonpolar and semipolar compounds in sea cucumber (Holothuria sp.) collected from coasts of Lengeh Port were extracted by Bligh & Dyer method. The extraction of nonpolar and semipolar natural compounds was conducted by Hexane and Ether, respectively. After condensation, the prepared samples were injected into gas chromatography machine equipped with mass spectroscopy; and mass spectra obtained, using Eight Peak reference, and Kuats index (KI) and its conformity with standard Kuats index was also assessed.The compounds in Hexane-Ether phases were identified. Based on the results, in the Hexane phase of sea cucumber issue, there were nine compounds including: 2-0ctanol (5.23 %), 5 Methyl 2-Hexanol (8.05 %), 2-Nonanol (2.5%), Cyclohexasiloxane, Dodecamethyl (2.09%), 3-Hydroxystearic (1.66%), Methyl Arachidonate (20.65%), 1, 4, 8, Dodecatriene (21.71%), Oleicacid (30.27%), and, I-Dodecanol (2.52%). There were also seven compounds in the Ether phase including: Tetradecane (0.63%), Palmitoleic acid (1.23%), Palmitic acid (1.63%), Oleic acid (40.31%), Stearic acid (3.40%), Methyl Arachidonate (28.62%), and 1, 2- Benzendicarboxlic acid (2-ethyl hexyl) (2.71%). We found that in both phases the main ingredient is Oleic acid. The investigation of antioxidant activity was conducted by the OSI and Rancimat apparatus. We detected no antioxidant activity in the sea cucumber compounds.

Shrimp farming industry has rapidly expanded in the south of Iran and in particular in Hormozgan Province along the coastal line during the past decade. A survey was conducted for evaluation of environmental impacts of effluents From the shrimp farms during culture season (July-December 2003) of Tiab area in Hormozgan Province. The physico-chemical parameters such as air and water temperature, salinity, pH, dissolved oxygen, BODs, nitrite, nitrate, total ammonia, inorganic phosphorus and total phosphorus were recorded monthly From 9 stations. The stations consisted of two inlets (stations 1, 3), two outlets of effluents (stations 2, 4) and the remaining 5 stations were located along the coastal lines. The parameters were measured at 21- 40°C, 22-39°C, 37-54ppt, 7.85-8.38,4-8.1mg/L, 0.2-8.5mg/L, 0.11-0.186mg/L, 0.001-0.029mg/L,0-0.016mg/L, 0-0.043mg/L and 0.014-1.4mg/L) respectively. The results showed that the range of most of the measured parameters such as water temperature, salinity, BODs, ammonia, nitrate, phosphate and TP in the outflow waters (2, 4) were higher than inflow (1,3) and coastal waters (5, 6, 7, 8 ,9). Statistical analysis of variance (ANOVA) demonstrated a significant difference between outlet effluent and other stations (P<0.05). We also concluded that the nutrients in the culture effluents are somewhat used by fauna of the Tiab creek, hence decreasing the pollutant load of the effluent.

Embryonic and larval development stages of yellow fin seabream (Acanthopagrus latus) were studied in two average temperatures (21 and 24°C) in Marine Fish Research Center in Emam Khomeini Port. Egg diameter in initiation of fertilization was 739.35±0.0081m and during final hatching it was 792.36±0.0095m. The average egg diameter from fertilization until final hatching was 763.49±0.0016m. The average egg diameter was 751.81±0.0064m inmurola stage, 767.55±0.0074m in nurula stage, 779.97±0.0084m in appearance of heart stage and 780.84±0.0086 in the increasing of pigmentation stage. Duration of egg incubation and embryo development of yellow fin seabream (Acanthopagrus latus) was 31 hours and 15 minutes at 20±1oC and 26 hours and 15 minutes at 23±1oC. In this study, 20 stages of embryo development of yellow fin seabream were identified through incubation period from fertilization to final hatching.It seems that water temperature can be an effective environmental factor in the fish embryo development, so that hatching at 20±1oC occurred in 5 hours later than when at 20±1oC. Temperature change had no effect on the number of larvae and characteristics of embryo development. The information gathered through this study is useful when planning for artificial reproduction of this commercial species and can improve the propagation process.

The nutritional quality of commercially available Artemia strains is relatively poor in Eicosapentaenoic acid (EPA), Arachidonic acid (ARA) and especially Docosahexaenoic acid (DHA). Hence, it is essential and common practice to enrich this live prey with emulsions of special oils. One commercial ICES30/4 (Belgium), Linseed oil as a vegetable oil, Cod liver oil and Sturgeon ovary oil as two animal oils with EPA amounts in these oils were 6.29, 0.03, 11.39, 7.55 and the DHA amounts were 20.90, 0.00, 7.64, 2.76 respectively with three concentrations (100, 200 and 300ppm) during two enrichment periods (12 and 24h) were tested in order to improve the HUFA content, the DHAIEPA ratio and ARA content of Artemia urmiana nauplii.The results showed that Artemia enriched with different levels of vegetable oil and enrichment periods was poor in relation to either HUFA content and DHAIEPA ratio but the fish oils and emulsion resulted in HUFA incorporation. Sturgeon ovary oil caused the poorest DHAIEPA ratio enrichment (0.40 in 300ppm-24h) but the commercial emulsion (ICES30/4) was found as the best for DHA/EPA ratio enrichment (1.20 in 300ppm-24h). Cod liver oil (0.53 in 100ppm-24h) can be a good internal source substitute for improving the DHAIEPA ratio enrichment compared to ICES30/4 due to price and availability. As a result, HUFA content was increased with enrichment level 200ppm during 24h. Also, all oil sources improved lipid and protein percentages in A. urmiana nauplii.

In order to determine the reproduction period, the peak time of spawning, length of maturity and mesh standard size for False Trevally (Lactarius lactarius), we conducted a study from November 2007 to October 2008 in coastal waters of the Oman Sea. A total of 702 False Trevally specimens were collected randomly from the catch composition of gillnets and Ferdows-3 stem trawler.Mean total length and total weight were estimated at 22.7±2.13cm and 142.2±41.64g for females and 20.4±1.89 and 103±29.7 for males respectively. Male to female sex ratio was 0.37:1 and females were more abundant than males in all months except June and August. Males had smaller sizes than females and the females outnumbered the mails up to the total length 25.5cm. The maximum of GSI was estimated at 3.69 for females in June and 0.89 for males in July. The trend of GSI and the frequency of maturity stages showed that reproduction period was from February to September with a spawning peak in August. Absolute fecundity was calculated at 102032 ova and relative fecundity was estimated at 4491.9 ova and 780.7 ova to total length and total weight respectively. Lm50% (length of maturity) and standard mesh size was calculated at 24.4cm and 3.9cm, respectively.

Water quality was studied in Mahshahr creeks from 2005-2006. Due to special characteristics of Mahshahr creeks, high fisheries potential and sever exploitation and human pressure, WQS index was selected for determination of ecological health status of the area. Eight creeks Ghannam, Zasngy, Doragh,Ahmady, Darvish, Patil, Ghazaleh and Bihad were selected and monthly sampling of physical and chemical parameters was done by bottle sampler. Six primary water quality parameters were used to develop an integrated measure of overall water quality. The parameters included Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD5), Total nitrogen (TN), Total phosphorus (TP), pH and Ammonia (NH3). The results of two ways ANOVA showed that differences were significant only for nitrite between seasons and for pH, ammonium, nitrite and total phosphorus between creeks. Based on index description, parameters pH, NH3 and DO were placed in grade five indicating good quality for water. Total nitrogen was in grade three indicating poor quality and BOD5 and total phosphor were in grade one showing bad quality for water. According to the index, high similarity was found in studied creeks and the total value was found to be 3.33 for the whole studied area, indicating poor water quality.

Biochemical aspects of ovarian fluid were investigated in 10 specimens of the Ship (Acipenser nudiventris) by assessment of ionic organic composition and their relationships with osmolality. Also spermatozoa motility of the ship sturgeon was investigated in different. Percentage (5, 10, 25, 50 and 100%) of ovarian fluid (pooled 6 samples). Ovarian fluid contained 104.78±32.12mmol/l Na+, 3.43±1.08mmol/l K+, 3.26±0.87mg/d Cla2+, 7.32±1.06mEq/l Mg2+, 0.606±0.207mg/dl protein, 24.88±13.02mg/dl cholesterol and 60.35±14.49mg/dl glucose.The pH of ovarian fluid ranged from 7.29 to 8.10 and osmolality ranged from 185 to 212mOsmol/Kg. There was also significant positive correlation between Na+ concentration and osmolality (r=0.835, P<0.01). When ship sturgeon semen diluted with 50 and 100% ovarian fluid, the spermatozoa remained immotile. The total duration of motility and percentage of motile spermatozoa was greatly reduced when semen was diluted in ovarian fluid higher than 5%. We found that the spermatozoa of ship sturgeon are immotile in the ovarian fluid because of ovarian fluid composition such as high concentration of K and osmotic pressure.

Rainbow trout with initial body weight 4.16±0.25g were fed diets that contained crude protein 42%; gross energy 4400Kcal/kg DM; crude fat 10% including graded levels of canola meal (CP 35% DM). A growth trial was conducted over 16 weeks at a water temperature of 12±1°C. At the end of the growth trial, in addition to body composition analyses, plasma triiodothyronine (T3) and thyroxin (T4), cholesterol and liver fatty acid composition were measured. Replacement of fish meal with canola meal (10 to 57% replacement) did not significantly affect the growth performance (P>0.05). At 16th week, plasma cholesterol levels were reduced in fish fed with all diets in comparison to 8th week. Plasma T4 levels were significantly higher in the canola meal-fed fish sampled after 16 weeks, but no significant differences in T3 levels were obtained (P>0.05). Proximate composition was affected by dietary treatments. The liver fatty acid composition reflected that of the fish fed with canola meal diet has a higher level of polyunsaturated (n-6) fatty acids compared to the control group in which a higher content of n-3:n-6 ratio was seen as opposed to the treatment. With increasing canola meal in diets, the cost of final food was reduced. This study showed that canola meal has potential to replace substantial levels of fish meal in diets for carnivorous fish without compromising performance.

We studied concentration of heavy metals Cd, Pb, Cu, Ni in the muscle, liver and gill tissues of Epinephelus coinoiedes caught in autumn 2006 from Hendijan Coastal waters in the Persian Gulf. After biometrical measurements, the muscle, liver and gill tissues of 30 randomly selected fish were separated; metals were extracted from the tissues using chemical digestion method with pure nitric acid and their concentrations were determined by AAS. Mean concentrations (ppm/dry weight) were compared with the international standards such as WHO, UKMAFF and NHMRC. The mean concentration for Cd and Pb in all tissues with the exception of muscle tissue, were found higher than permissible limit. We found a positive linear relationship between accumulation of Ni, Pb and Cu in muscle tissue with total weight and total length factors (P<0.05). There was no significant relationship between mean concentration of Cd in muscle tissue with total weight and total length factors (P>0.05).

One of the compounds of crude oil is Polycyclic Aromatic Hydrocarbons (PAHs). This study was conducted in the toxicology laboratory of Persian Gulf and Oman Sea Research Center, Bandar Abbas in spring 2005. Four commercial fishes were exposed to 0ppm and 12ppm dosages of crude oil in long-term bioassay examination. After 8 days, exposed fish were freezed and packed separately and then sent them to IBB (Institute of Biochemistry and Biophysics) of Tehran University for determination of PAHs accumulated in their muscle. PAHs measurement was done with GC-FID. In this research, the amount of each compound of PAHs and total PAHs in each dosage was calculated separately for each species. The result of data analysis shows that the mean accumulation amounts of PAHs (SD±x͞) in tissues of control Pseudorhombus elevatus, Euryglossa orientalis, Siganusjavus and S. sutor exposed to 0ppm dosage of crude oil were 929.66±2.51ppb, 1009±11ppb, 1131±35.0ppb and 487.6±4.0ppb and mean accumulation amounts of PAHs (SD±x͞) in those exposed to 12ppm dosage of crudeoil were 3843±13.52ppb, 4272±18.77ppb, 2911±35ppb and 2309.6±11ppb respectively. According to t-test, we concluded that in all four species the accumulation of crude oil in their muscle tissues between two mentioned dosages were significantly difference (P<0.05). On the other hand, the high amount of PAHs in the control fishes probably is due to pollution of Persian Gulf.

Macro benthic invertebrate distribution and abundance in northern creeks of Boushehr province were analyzed by seasonal sampling from autumn 2000 till summer 2001. Sampling was carried out of sediments from bottom of nine stations which located in creeks and one control station in the sea by using of Van Veen Grab sampler.In additional, eight groups of macro benthos were identified which the most abundant populations among them were Gastropoda (51%), Bivalvia and Polychaeta (17.4%) and Amphipoda (5.3%) respectively. The maximum density of macro benthos was 2378ind/m2 in spring and the minimum was 1174ind/m2 in autumn and also maximum and minimum biomass was 79.06g/m2 in summer and l7.72g/m2 in winter. The average wet weight of macro fauna biomass was 49.95 (±33.6)g/m2.

A study was conducted on the effects of egg size OR length, weight, growth and survival of prelarval and early feeding stages of 19 female breeders of Persian sturgeon. The results showed that egg size can affect the total length and weight of prelarvae and there were positive and significant correlation between egg size and total length of prelarvae at the hatching stage and at 2,4,6,8 and 10 days post hatching (P<0.05). There were positive and significant correlation between egg size and weight of prelarvae at hatching stage (P<0.05), but at 10days post hatching differences were not significant (P>0.05).There were also positive and significant correlation between egg size and volume of yolk sac at hatching (P<0.05)but during yolk sac absorption, differences decreased gradually and volume of yolk sac at. 10 days post hatching were equal. Survival rate at yolk sac absorption stage increased with increasing of egg size but differences were not significant (P>0.05). However, during the first feeding stage the correlation between egg size and survival was very weak.

Chemical composition and fatty acid profile of common carp's gonad (ovary) were assessed. Protein, lipid, fatty acid profile and moisture content were determined during 4 seasons' summer, autumn, winter in 2007 and spring in 2008. For each season 10 samples were examined. Average of gonadosomatic index ill wild common carp was 7.53±5.02. Proximate composition of ovary during the study period showed the lipid at 8.06±2.20 protein at 23.26±4.85 and moisture at 67.12±3.85. The results showed lipid content of wild fish ovary increased from summer to spring (summer 6.875±0.53 autumn 7.07±2.12 winter 7.96±1.22 spring 9.44±3.62) protein content also increased from summer to spring (summer 12.920.09; autumn 23±1.32 winter 25.16±0.63 spring 27.11±0.63), moisture content decreased in this period (summer 75.235±1.75 autumn 68.25±2.28 winter 65.685±0.40; spring 63.43±0.11). Significant differences (P<0.05) in protein and moisture content were found during different seasons, but for lipid content the differences were not significant (P>0.05). Saturated and polyunsaturated fatty acids increased from summer to spring (spawning season). The major fatty acids identifiedin common carp ovary were Oleic (C18:1), palmitic (C16:0), Docosahexanoic acid (C22:6 DHA), Palmitoleic (C16:1), Arachidonic, AA (C20:4), Stearic (C18:0), Eicosapentaenoicacid (C20:5 EPA) and Linoleic (C18:2) in all seasons. Lipid, protein and w3 PUPA increased during gonad maturation. It seems that these resources of energy are necessary for embryogenesis.

Bacterial and fungal microflora of Litopenaeus vannamei cultured in Choibdeh, Abadan was studied. For this purpose, PLs before and after stocking and those shrimps persisting on food tray from June to August, 2006 were taken randomly. Live samples transferred to microbiology laboratory of South Aquaculture Research Center, Ahwaz. Special culture media (e.g. Tryptic Soy Agar + 1.5-2% Nacl & Sabouraud Dextrose Agar + 1.5-2% Nacl) were used for bacterial and fungal culture. We isolated 10 bacterial species of which Vibrio alginolyticus (36.92%) had high abundance among bacterial species. We also isolated and identified three fungal species including Aspergillus niger (66.66%) A. fumigatus (16.66%) and Fusarium sp. (16.66%). A. niger was predominant among fungal species. All bacterial and fungal species that were identified were opportunistic.

This survey was carried out during 2004-2005 in Bahmanshir River located in southern part of Khouzestan province. The main water supply of the Bahmanshir River is obtained from Karoon River which is discharged into the Persian Gulf. In this project five stations were selected from Hafar Branch to the estuary of the River and physicochemical factors of water such as pH, Fe, DO, BOD5, Nitrate, Nitrite, and TSS were measured. The sampling was conducted montly.The water temperature and pH changed from 13.2 to 27.5°C and from 7.2 to 8.7°C respectively. The minimum and maximum dissolved oxygen were 5.4 and 11.9mg/l, respectively. The results indicated that the amount of nutrients such as nitrate, nitrite, and ammonia were relatively low in Bahmanshir River.