Iranian Scientific Fisheries Journal
Year:2004 | Volume:13 | Issue:3|Papers Count:15

In this research Quil-A and levamisole as immunostimulants were used both by immersion route (Quil-A, 40 mg/L and levamisole, 50 mg/L) and oral route (Quil-A 5, 10 mg and levamisole 20, 40mg) in common carp (Cyprinlls carpio)(mean weight ~80g) daily for 20 days. after twenty days of treatment with immunostimulants, stained heat killed Candida albicans and Bacillus cereus were injected intravenously via caudal vein. Two hours after injection, bIood and kidney tissue samples were collected. Phagocytosis rate of blood and kidney smears were died using Gimsa staining. Results showed that phagocytosis of Candida albicans cells by od leukocytes in immersion groups into 40mg/L and 50 mg/L levamisole and orally used 5 and 10 mg Quil-A groups were significantly increased in comparison with the control group. While fish given 20 mg levamisole orally did not show a significant difference with control group and phagocytosis in 40mg levamisole by oral administration was suppressed as showed significant difference with control and other groups. Phagocytosis of Bacillus cereus cells showed similar results to the Candida albicans cells. Phagocytosis rate in kidney tissue was also stimulated in all groups except for 20 and 40mg levamisole groups presumably due to immnunosuppressive effect of high levamisole rate.

This survey is part of identification and determination of cIupeidae (Genus Alosa), in southern Caspian Sea, Mazandaran and Golestan Province coastal waters during 1997-99. In this study, total of 336 fish samples were studied.The results showed that 4 species of cIupeidae, belong to: Alosa brashnikowii (Borodin, 1904), A. caspia (Eichwald, 1983), A. saposchnikowii (Grimm, 1887) and A. kessieri (Grimm, 1887). For species identification two morphometric and morphomerestic factors were used.One of the important factors of morphometric is gill rakers and, A. braschnikowii had 20-40 with average of 30.93±6.11,A. caspia had 110-125 with average of 118.3±5.23,A . kessleri had 60-73 with average of 66.82±3.31and A. saposchnikowii had 20-48 with of average of 32.83±4.93percent gill rakers.Another important morphometric factors are percent ratio of eye diameter to total length. A. braschnikowii had 2.9-5.82 and average of 4.72±0.53percent, A. caspia had 5.73-7.46 and average of 6.21±0.52,A. saposchnikowii had 6-9.33 and average of 7.3±1.8 percent and finally, A. kessleri had 4.27 -6.48 and average of5.46±0.71percent.

In order to culture the G. corticata for further agar extraction, during one year study (2001), 3 treatments with 3 different densities of 500, 1000 and 2000 g/m2 and 3 replicates were cultured in fiberglass tanks. During the culture period the parameters of temperature, pH and salinity were measured and 30-40 percent of water was exchanged once every two days. The aeration activity was constantly done and also 0.5g urea added into the water after exchanging the water.The biometric measurement of algae was carried out every week and ultimately end of the period culture, the daily growth and net production (wet weight) was calculated in proportion to g/m2. Also, amount of extracted agar (dry weight) estimated seasonally.In winter, the daily growth (%), net production and agar extracted (%) were estimated 1.46±0.11, 11.5±3.57 and 17.5%, in which these figures for three other seasons of spring, summer and autumn were: 3.74±0.31, 38.3±5.4, 19.3 and 1.5±0.28, 12.43±3.3,14% and 3.11±.04 2,6.9±0.61 and 15%, respectively. Some epiphytes and grazers were recognized in algae cultivation tanks such as Navicula, Nitzchia, Oscillatoria, Peridinium, Chaetoceros, Entromorpha, Dlva, and Isopoda, Nemertin and Nereis.Two seasons of spring and autumn showed the best daily growth and net production, and also the 500 g/m2 treatment was recognized the best culture treatment.

Regarding to the role of shrimp culture on economy of southern region of Iran, investigation of disease agents seems to be very important.In this study the effects of stocking density of P. indicus (4 treatments) on health indices of pond in semi-intensive system was investigated.The investigated health indices were: bacterial, fungal and parasits agents. The obtained data from this study indicated that the vibrio spp., Aspergillus sp. and Epystilis sp. had the highest contamination rate of the pond. ANOV A showed significant difference between the increase of bacterial and parasitical contaminations respect to stocking density (p<0.05).These differences are not significant among the ponds because the health indices were same for all of them (p>0.05).The liner regression showed relationship between the increase of bacterial and parasitical contaminations respect to stocking density.Also results showed that increasing of the shrimp density caused increase in all pathogen agents.

Rays have high stocks in the Persian Gulf and Oman Sea, and are caught as by-catch in different fishing gears. Yield and Quality of gelatin extracted from the skin of dominant ray species of Persian Gulf, included: Butterfly ray (Gymnura  poecilura), Sting ray (Himantrura gerrardi), Honeycomb Sting ray (Himantura uarnak) and Eagle ray (Aetomylaeus maculatus), were studied. Biometric results and the mean of skinning yield for each species were reported. Skinning yield for Eagle ray was 3.2% that was significantly lower than other species (with > 60%). Gelatin, extraction was done in constant conditions by Chloridric acid pretreatment. The results of qualitative identification of samples were positive and according to standards, concluded that the extracted products were gelatin. Also, total nitrogen, humidity and pH of samples were in standard limits, but ash content was upper than maximum standard level. Minimum concentration of extracted gelatins for gel formation was 2% and no significant differences were observed between extracted gelatin samples. Melting temperature of rays gelatins ranged 20-25°C.Maximumand minimum yield of gelatin extraction yield were 20.4% and 19.0%, respectively. No significant difference were observed between gelatin extraction yield of four ray species (P>0.05). Results suggested that for industrial uses, the skin of different ray species can be mixed and use together.    

Jajroud river with 140km length, inhabits various species of aquatics of which one of the main identified one is freshwater crab belongs to POT MIIDAE family with scientific name of Potaman persicum.In this study, 388 specimens from 5 sampling stations (Latian dam, Taraghion, Khojir, Giahan daroie and Mamloo dam) were connected since November 1998.All samples were transfered to the laboratory for reproduction studies and determination of spawning season, with studying the maturity stages of gonads and external eggs.The results showed that the spawning season of this species occurring in middle of spring, it was also found that P. persicum is a total spawner. The external maturity (of eggs) was classified to 7 stages.On the other hand the maturity stages of gonad was recognized in accordance with the color, size and egg diameter and classified to 5 stages.

A comprehensive hydrobiological and hydrological investigation conducted in Anzali lagoon from 1997 to 2000. During this study, a total of 5 phylum and 62 genera of phytoplanktons and 10 phylum and 50 genera of zooplankton were identified.The results showed that for phytoplanktons the abundance of Cyanophyta, Chrysophyta, Chlorophyta, Euglenophyta and Pyrrophyta were calculated 61.8%, 29.1%, 8.2% 0.7% and 0.2%, respectively.,The most abundance of zooplankton belongs to Rotatoria (60.8%), after that other group of zooplankton had more abundanc consist of Copepoda and its naupli (17.2%), Ciliophora (9.6%) and Rhizopoda (6.6%). Other zooplanktons had very few abundance.According to obtained results5 western region of Anzali lagoon (Abkenar) is a rich region of planktons in which the most dominant phylum of phytoplanktons was from Cyanophyta with genera of Oscillatoria, Anabaenopsis, Microcystis.The most abundance of zooplanktons were genera of Polyarthera, Brachionus and Keratella and from Arthropodaphylum, the most abundance genus was found Cyclops and its naupli.The Planktonic study indicated that Anzali lagoon is one of the richest lagoon in Iran with high production and potential water for feeding of fishes and their larva.

Mako reservoir which is situated on Zangmar River, located in western Azarbaijan province. It has an average area of 800 hectares. There isn't any fishing in Mako reservoir, and the purposes of construction were producing water supply for agriculture use and drinking water. The seasonal sampling were carried out in 5 stations by gillnet methods during 1998-1999. For catching the Capoeta capoeta, gillnet mesh size of 27mm was used. Capoeta capoeta was dominant species (90%) and Carassius aurata gibelio and rainbow trout had the lowest populations.Analysis on based Leslie and Delury methods showed that this reservoir has a range of 9.4-10.7 tons of Capoeta capoeta. By using Gulland method, the MSY estimated 4.5-4.8 tons.One year data collection and analyzing the data showed the average forklength were 23.9±4.3cm, mean weight of 162±68g and the mean age 2.6±0.68years. Age composition showed that maximum and minimum frequency was in 3+ and 5+, respectively. Infinite length (L ∞) and the growth coefficient (k) by using Walford formula computed 35.6 cm and 0.39 per year. Total mortality (Z) of this species determined 0.74. Natural and fishing mortality calculated 0.37 and 0.37, respectively.

In this study in order to investigate the effects of LHRH-A and its combination with dopamine antagonist, Metaclopramid (MET), Dopeidon (Dam), 21 females of Hypophthalmichthys molitrix were studied in Shaid Ansari fish rearing and propagation center during June 2001. The results showed that LHRH-A+MET treatment group with 2g+ 15µmg/kg dose, indicate high response (100%) in brood fishes, and other factors have significant differences (p< 0.05) compared to other treatment groups. Also, investigation on the degree-hour of sexual maturity in different treatment groups show that the groups with introduced Dam (in suspension from) as dopamin antagonist combined with LHRH-A, indicated higher degree-hour (288,366 degree-hour) and has significant difference compared to other treatment groups. In addition this study indicates that MET as suitable dopamine antagonist can strengthen LHRH-A for final sexual maturity, also can decrease LHRH-A dose for injection, but Dom has not the mentioned effects in artificial propagation of Hypophthalmichthys molitrix and this can be due to applying suspension form of antidopamin in hormone solution of this research.

The effects of feeding frequency on growth rate, food conversion ratio (FCR) and survival in juvenile beluga sturgeon were studied through two phases of rearing. 360 beluga fingerlings with an average weight of 20.51±0.33g were reared through a period of 60 days in the first phase and about 180 fingerlings with an average weight of 77.55±1.18g were reared through a period of 95 days in the second phase in fiberglass tanks (500 L) with a water flow rate of 0.2 L/sec under similar conditions of rearing (dissolved oxygen, light, water velocity, etc.). Three different feeding frequencies were used for each phase (3, 5 and 8 times feeding per day) with three replicates.It was evident from the results obtained from the first experimental phase that with an increase in feeding frequency there was an increase in growth rate, weight increase percentage and specific growth rate as well as a decrease in FCR value. However no significant differences were observed in the three group~ studied (P>0.05). Whereas in the second phase of study significant differences (P<0.05) were observed in the parameters studied (length, weight and FCR) in the third study group (with 8 times feeding per day) at the end of study period: We may therefore conclude that growth rate, nutritional uptake and social behavior of each fish species are dependent on its feeding frequency.

The aim of this study was recognition of pollution, which is polluted by heavy metals (Lead and mercury). This study was carried out with cooperation of France Food Agency and AFSSA according to the latest international and Europe Union standards, for two years during 2000-2001. The sampling stages were done according to the European Union enclosed No. 4 in guide direction 96/23 by method to once time sampling, which was collected per 100 tons shrimp production. So, 42 sample in a year and were connected 84 samples totally during two years that the sample provided for each one was 500g. All samples were frozen and then were sent to France and AFSSA for analyzing. To study of heavy metals mercury and lead, in samples methods of chromatography with high efficiency HPLC and LC-MS and GC-MASS have been used.Quantitative determination rate in Pb was 20 and for Hg was 10µg/kg. The rest amount of this metals which cause we start our effort for controlling Pb and Mg pollution was found 500µg/kg.In this study, the quantitative determination rate of all samples as measured less than 500J.1g.

In this study shrimp shell waste and their derivatives Chitin and Chitosan were studied for 60Co ,137Cs 90Sr and 54Mn adsorption from low-level radioactive liquid waste(LLW) in batch and continuous method. Shrimp shell waste, demineralized shrimp shell waste, Chitin and Chitosan were selected as natural organic adsorbent. The batch and column ion exchange experimental results show that the sorption was depended on pH, particle size, adsorbent type, deactylation factor and treating time. Temperature changes have an effect on treating time but no effect on total sorption. Chitin derivatives. Particularly chitosan 1 & 2, are efficient for radioisotopes removal. Chitosan 1 with 50-70% deactyilation factor has the best aptitude for removal of radioisotopes and the shrimp shell has the worse.

In a research project during 1999-2000, transferring polymorphism in blood serum as well as several morphometric and meristic characteristics were determined in 7 groups of carps of different fish farms.Transferring polymorphism in carp is expressed by the occurrence of one or two band phenotypes determined by a series of codominant alleles. In this study, there was significant difference especially between sea and cultured carp (P<0.01).Sampling of sea carp in general have been from race of carp with BB dominant genotype, but fish sample from shahid rajaii fish farm have shown variety genotype including AA, AB, BB, AC, BC and CC.In morphological investigation, the C.V. of meristic characteristics, which is under genetic bases such as number of fin rays and number of scales on lateral line was higher significantly in those fishes caught from the sea than cultured fishes (P<0.00).Relative comparative of mophometric characteristics such as head length to standard length and width of body showed also significant difference between those two groups (P<0.05).