Iranian Journal of Fisheries Sciences
Volume:12 Issue: 1, Jan 2013

The Caspian Sea and its basin (e.g. Anzali wetland) is one of the natural habitats of wild common carp Cyprinus carpio. In this study the genetic structure of this species. In the south-west of Caspian Sea (the Anzali wetland) was investigated using PCR-RFLP analysis of D-loop region. Two hundred of mature fish were collected from 5 stations (40 individuals from each station) including Siahkeshim protected area (SK), Selke wild refuge (S), Sorkhankol wild refuge (SO), Abkenar (A) and the Anzali wetland estuary (E) during spawning season. A 420bp fragment of D-loop was amplified and the PCR products were digested with forty endonuclease enzymes. Four out of them: TasI, SmaI, SspI and ApoI showed polymorphism. Seven different composite haplotypes were detected among 5 stations and AAAA was the most frequent. FST ranged from 0.003-0.99. Over all stations, average haplotype and nucleotide diversity were 0.13 and 0.01, respectively. The highest haplotype (0.42) and nucleotide (0.06) diversities were found in (SO) station. AMOVA test showed that the Anzali wetland probably consists of two different populations of wild common carp which are distributed in SK, A-SO-S-E stations. The results of this study will be useful as a guideline for conservation, restocking as well as cultivation purposes of wild common carp in the Caspian Sea.

Diazinon is commonly used for pest control in the agricultural fields in north of Iran. This study was conducted to determine the chronic toxicity of organophosphorous pesticide (Diazinon) in vaccinated fish and its effects on some hematological parameters and biochemical blood plasma profiles of Grass Carp (Ctenopharyngodon idella).This experiment was carried out in three groups. The first group was vaccinated and exposed to diazinon (group A) while the second group was vaccinated and bathed with PBS bath (group B). The remaining fish were used as unvaccinated fish and were kept in clean water separately (group C). Diazinon was applied at concentrations of 2 mg/L for 12 hours since the experiments were initiated. The experimental groups(A and B) showed significantly lower values (p < 0.05) of erythrocyte count, haemoglobin content, haematocrit, leucocytes, Lymphocyte, myelocyte and monocyte, as well as in alkaline phosphatases, alanine aminotransferase, aspartate aminotransferase and, lactate dehydrogenase compared to the control group(C). Values of MCV, MCH and MCHC of experimental species (A and B) were compared to the control group(C). The results of examinations of the biochemical blood plasma profile indicate a marked neurotoxic effect of diazinon in fishes. Changes in values of both erythrocyte and leukocyte profile after exposure to diazinon-based preparation may be referred to disruption of haematopoiesis as well as to a decrease on non-specific immunity of the fish.

The species Gracilariopsis persica was first described by Bellorin et al. (2008). G. persica grows from late September to July and shows high growth rate from January to May in the Persian Gulf. Tissue growth and branch induction of red seaweed, Gracilariopsis persica from the Persian Gulf investigated under various culture levels of temperature, light intensity, photoperiod, salinity, initial length, propagule density and chemical preservatives. Optimal size of propagules used as seed was 2 cm and faster growth of tissue and branch induction obtained at lower density. The apical part of the G. persica showed as the starting point of growth. The G. persica showed optimal growth in PES medium at 24°C, 60μmol m-2 s-1 light intensity, 12L: 12D and salinity of 39‰. But maximum branch production occurred under condition of 24°C, 20 μmol m-2 s-1 light intensity, photoperiod of 16L: 8D and salinity 39‰. Addition of chemical preservatives of p-hydroxybenzoic acid and potassium sorbate in culture medium showed marginal suppression on tissue growth and branch induction, that suitable for preparation of semi-axenic culture condition.

In this study, lethal concentration (LC50) values of cinnamon hydrosol (Cinnamomum zeylanicum) on carp (Cyprinus carpio) were investigated. In practice, experimental setup was constituted 30 fish (a total of 180 fish with 30 control fish) to be placed in three replicates. Hydrosol was added into aquariums at the doses of 0.5, 1, 2.5, 5 and 10% and determined mortality times of carp exposed to these concentrations. Percentage death of fish calculated in these concentrations. Mortality was observed at all treatments exception of dose of 0.5 %. The results indicate that the hydrosol had swimming changes, lethargy, lack of breath and leaning to the depth of the aquariums at all of the concentrations. The results of regression analysis indicated that the mortality rate (Y) is positively correlated the concentration (X) having a regression coefficient (R) close to one in each case. While the 1 h LC50 value (with 95% confidence limits) of the safe dose of C. zeylanicum hydrosol was estimated at LC50=4.39%, 2 h LC50 value=2.629%, and 12 h LC50 value= 1.027%.

In this study, some metals (aluminium, chromium, copper, iron, manganese, lead, zinc and vanadium) and metalloid (silicon) were determined in water, sediment and some tissues of fish Cyprinus carpio from Mogan Lake. Fish samples were caught in March 2007. As a result of the examination of metals in the water aluminium has the lowest and silicon has the highest concentration. In sediment samples taken from Mogan Lake it was determined that silicon had the highest and lead had the lowest concentrations. Respectively accumulation of metals in gills, muscles and livers was observed to follow the order of Zn > Fe > Si > Al > Mn > Pb > Cr > V, Si > Fe > Zn > Al > Pb > V > Cr > Mn and Fe > Zn > Al > Si > Pb > Mn > V > Cr > Cu.

The objective of this project is to compare growth and survival rate in Chinese carps reared under traditional culture conditions versus those reared in ponds treated with slurry (anaerobic fermented of cow manure). This experiment was conducted using two treatments; one treatment using slurry and the other using cow manure plus chemical fertilizer as the control with three replicates for each. Chinese carp were stocked at the density of 2375 individuals/ha (Silver carp 60%, Bighead 15%, common carp 17% and grass carp 8%). In this investigation common carp and grass carp were fed with formulated diets and fresh grass, respectively. The survival rate in the slurry treatment was higher than that in traditional treatment. Survival rates were 98, 100, 84 and 52 percent for silver carp, bighead, common carp and grass carp, respectively in the slurry treated ponds and 96.0, 98.3, 82.8 and 20.0% percent in the control ponds. The results showed that survival rate and yields were higher in the slurry treated ponds than that in the control. The increasing percent of yield were 13.5, 2.6, 18.4 and 85.3 in silver carp, bighead, common carp and grass carp, respectively. The survival rate for grass carp was two times higher in the slurry treatment than control. Zooplankton abundance in slurry ponds was higher than that in control, but blue-green algae density in slurry treated ponds was less than (over 50%). In general the results indicate that slurry with higher nutritional content is more effective on the survival and growth rate of fishes and also is more efficient in the proliferation of plankton in particular zooplankton. Slurry also reduces the use of chemical fertilizers.

Recognizing the significance of the life stage of fish for nano-eco-toxicological studies, the acute toxicity of colloidal silver nanoparticles (AgNPs) was tested in three different life stages of rainbow trout. Fishes were exposed to colloidal AgNPs at nominal concentrations of 100, 32, 10, 3.2, 1, 0.32, 0.1, and 0.032 mg/L. The estimated 96 hr LC50 values were 0.25, 0.71, and 2.16 mg/L for the eleutheroembryos, larvae and juveniles, respectively, revealing a higher sensitivity for the early life stages. In addition, a dose-dependent blood plasma reduction of chloride and potassium, also increase of cortisol and cholinesterase were observed in the juveniles to exposed AgNPs when compared to the controls. Thus, colloidal AgNPs should be classified as “very toxic” and “toxic” to the eleutheroembryo-larva and juvenile stages, respectively, meaning that the release of nanosilver into the aquatic envi‌ronment or its direct application as an antimicrobial agent in aquaculture should no longer be allowed.

The distribution pattern of Bullacta exarata was studied in different seasons of 2004 at south shore of Hangzhou Bay, China. We found that the distribution pattern of B. exarata was aggregated in each season by Taylor's power regression and Iwao's plot regresses methods (P < 0.001). Based on two-way ANOVA analysis, the results indicated that the densities were significantly affected by the factors of season (P < 0.001), distance to the dyked dam (P < 0.001) and the interaction between them (P < 0.001). The densities distribution followed with the distance gradient was significantly different in each season with one-way ANOVA analysis. The results of Pearson correlation coefficients analysis on data of density indicated that in the warmer seasons (spring and summer) the highest densities occurred at 150 m to the dyked dam, while in the cooler seasons peak in densities were at 250 m to the dyked dam (autumn and winter). In the study area, seasonal variation of B. exarata densities should be the response of the species to the environmental change, especially the food resource.

Remote sensing has changed modern oceanography by proving synoptic periodic data which can be processed. Since the satellite data are usually too much and nonlinear, in most cases, it is difficult to distinguish the patterns from these images. In fact, SOM (Self-Organizing Maps) model is a type of ANN (Artificial Neural Network) that has the ability to distinguish the efficient patterns from the vast complex of satellite data. In this study, the sea surface temperature data and chlorophyll a related to a part of south Caspian Sea were investigated weekly by NOAA satellite for three years (2003–2005) and the annual and seasonal patterns were extracted (elicited) with their relative frequency using the SOM model. In all patterns the Caspian Sea coast has the highest chl-a and when you go away from the shore the rate decreases and when you approach to the middle parts the chl-a is of the least proportion on the sea surface.

The effects of Z. multiflora essential oil (EO) and nisin (N) on fresh rainbow trout (Onchorynchus mykiss) fillets were studied during 18 days storage at 4 ºC. Bacteriological and organoleptical evaluation were performed on fresh rainbow trout as the functions of treatment and storage time. Treatments included the following: A (control), E1 (treated samples with 0.2 % EO), E2 (treated samples with 0.4 % EO), N (treated samples with 150000 IU nisin/ kg), E1N (treated samples with Nisin and 0.2 % EO) and E2N (treated samples with nisin and 0.4 % EO). Total viable count (TVC) reached the value of 7 log cfu/g on days 9-12 for control sample and on days 15-18 for E1N and E2N samples. Meanwhile, in the sensory evaluation test, shelf life of rainbow trout fillets was 9 days for control samples and 12 days for other treated samples.

The Çaygören Reservoir was sampled monthly from February 2007 to January 2009 at three stations to determine the relationships between the chlorophyll-a (Chl-a) dynamics and soluble reactive phosphorus (SRP), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), water discharge, water transparency, water temperature (T), specific conductance (SC) and pH. Thermal stratification occurred in the reservoir from May to September. The maximum chlorophyll-a concentrations were measured (using a YSI multi probe) in the fall and the minimum concentrations were recorded in the winter. Differences in the concentrations of chl-a, SRP and NO3-N were significant among seasons (p<0.01), but not among sampling stations (p>0.01). The differences in the Secchi disk transparency were significant both among sampling stations and seasons (p<0.05). The results of this study suggest that high chl-a concentrations resulted from the increase in available light in the spring and deep mixing in the fall which provided nutrients needed for phytoplankton growth.

The effects of whey protein (12%) and sodium alginate (0.5%) on chemical, microbial and sensory changes and shelf life in kilka during frozen storage are investigated for up to 6 months. Total bacteria count and Staphylococcus bacteria counts(2 / 51 and 1 / 44 log CFU/g) in coated samples showed decrease in comparison with control samples(3.21- 2.28 log CFU/g). Moisture of coated samples had significant increase than control treatment (p<0.05). protein, lipid, ash and calorie were higher in test samples as compared with the control samples. Free fatty acids, TBRS, peroxide value, TVN and pH in coated samples showed significant decrease in comparison with control (p<0.05). Sensory evaluation of coated samples showed significant difference in comparison with control (p<0.05). It is suggested that whey protein edible coating incorporated with sodium alginate can enhance quality and increase shelf life of kilka fish in storage of freezing up to 6 months.

Poultry by-products and rainbow trout (Onchorhynchus mykiss) viscera are abundant and underutilized resources that can be used as a unique protein source to make protein hydrolysates. In this study protein hydrolysate were made from these two different sources with Alcalase 2.4L. The functional properties of Fish viscera protein hydrolysate (FPH) compared to poultry by-products protein hydrolysate (PPH) were studied: Solubility, water holding capacity (WHC), oil absorption capacity (OAC), colour, emulsifying and foaming properties. Furthermore, the products were characterized by analyzing their amino acid composition. WHC, emulsifying activity, emulsifying stability and foaming properties and color of the FPH was significantly (P < 0.05) higher than PPH, while OAC was not significantly (P > 0.05) different. Methionine and histidine in both protein hydrolysates were the limiting amino acids and FPH had more hydrophobic residue. The differences in the amino acid composition between PPH and FPH may also be responsible for their different behaviours at various pH.

Although there is growing evidence that metals can be toxic to various aquatic species, there is still insufficient knowledge to integrate this information in environmental risk assessment procedures. In this study, we have investigated bioaccumulation and effects of nickel and vanadium on mortality and growth of Artemia urmiana and Artemia franciscana. The in 24 h of A. urmiana and A. franciscana exposed to nickel and vanadium were 0.0072, 0.0114 mg/l and 0.0107 and 0.011 mg/l respectively. In growth experiments, the length of animals was considered as growth index. Results indicates that the mean length of animals in (0.001, 0.002 and 0.003 mg/l) Ni and V on first, 5th, 7th and 11th days of life significantly decreases in comparison with control groups (p<0.05).Bioaccumulation of Ni and V in the same concentration, after 24 h in nauplius and also in adults of A. urmiana and A. fransicana were statistically significantly higher than of the control groups (P < 0.05). Both species accumulate nickel and vanadium in their bodies. However A. urmiana is more resistant to the heavy metals. Results show, nickel is less toxic than vanadium on Artemia.

Studies were conducted to determine a disease outbreak in 14 day old post-larvae of abalone (Haliotis diversicolor supertexta) which caused mass mortality in July 2010 in Shanwei, China. Twenty-nine bacterial strains were isolated from a sample pool of 10 diseased post-larval abalones on 2216E marine agar plates during a natural outbreak of the disease. Among them, a dominant isolate (referred to as strain 21) was found to be highly virulent to post-larvae in experimental challenge tests, with an LD50 value of 1.0 ×104 colony forming units (CFU) mL-1 on day 3. API 20NE kits and 16S rDNA sequence analysis, identified strain 21 as Oceanomonas doudoroffii. It was susceptible to 10 and moderately susceptible to 1 of the 16 antibiotics examined when antibiotic sensitivities of the bacterium were assayed. Results of this study implicated Oceanomonas doudoroffii strain 21 as a cause of mortalities in post-larval abalone from Shanwei, China.

The aim of this study is to provide necessary information on the biology of mosquitofish in Seyhan Dam Lake in Adana, which is located in southern part of Turkey. The population structure of eastern mosquitofish Gambusia holbrooki Girard, 1859 was studied in Seyhan Dam Lake. A total of 1582 specimens (772 males and 810 females) were collected monthly from January to December, 2007. The age composition of the sample range between 0+ and 2+in both sexes. The sex ratio was M:F= 1:1.04. The length-weight relationship calculated for all individuals, with W=0.0129 x L2.927. von Bertalanffy growth parameters were for males, L∞=3.31cm, K=0.6597 year-1, to =0.9483 year; for females L∞=6.62cm, K=0.2369 year-1, to =0.9259 year; for all samples, L∞=5.84cm, K=0.2369 year-1, to =-1.0740 year. A total of 102 stomachs were examined and total of organisms identified from alimentary canal. The diet mainly consist of Diptera (Chironomidae (pupa) 29.40%; Diptera (adult) 24.50%), Egg (mosquito 14.70%; different organisms 1.96%), Crustacea (Copepoda 9.80%, Cladocera 3.92%), Coleoptera 4.90%, Hemiptera 1.96%, Fishes (G. holbrooki 3.92%), Other Hymenoptera 1.96%, Tricoptera 0.98%, Plecoptera 0.98%, Formicidae 0.98%. These data were conducted to compare with the results of other studies to carry out for other geographic areas.