Iranian Journal of Fisheries Sciences
Volume:16 Issue: 4, Oct 2017

Heavy metals and some organic substances which are drained into the aquatic environments and cannot be decomposed or eliminated will sink into sediments or find their way into different levels of food chain. Bioaccumulation is the process of continuous deposition and aggregation of these substances into the body tissue of living organisms. Mollusks are remarkably appropriate to be used as bio-indicators because of their motionless or almost sessile nature, relatively high abundance, selective absorption of certain ions, and worldwide distribution in marine and inland aquatic habitats. Chiton lamyi is a sedentary species from the phylum, Polyplacophora, which is usually abundant on the rocky shores and intertidal zone of marine environments.
Sediment and Chiton samples were taken from four stations of Chabahar Bay in autumn 2013. After acid digestion of samples, the concentration of heavy metals (mercury, cadmium, arsenic, nickel, lead and copper) were measured by the graphite furnace atomic absorption apparatus, and the bioaccumulation factor in relation to sediment was calculated. The highest concentration value was calculated as 3.28 for cadmium in the Hafte Tir station. The results of this study indicated that chitons can be used as an appropriate bio-indicator for heavy metals particularly cadmium pollution in the marine environment.

Enteric red mouth disease (also known as Yersiniosis) is one of the most significant bacterial infections in coldwater fish farms that cause significant mortalities and economical losses in the salmonids fish farms, especially in rainbow trout (Oncorhynchus mykiss). ERM is caused by the gram negative pathogen bacteria Yersinia ruckeri that has five O-serotypes (O1, O2, O5, O6 and O7), five outer membrane protein types (OMP types 1–5) and two biotypes 1 and 2. The disease has a wide geographical distribution in various fresh or sea water fish. More than twenty species mainly of Salmonide origin have been affected and this number is likely to rise in the future following the introduction of new species and the increase of aquaculture trade. The disease can affect fish of all age classes but is most acute in small fish up to fingerling size. Affected fish may reveal different clinical symptoms depending on species, age and temperature. The most characteristic and common clinical signs of the disease include lethargic behavior and inactivity, swimming near the surface, anorexia, and darkening of the skin. The reddening of the throat and mouth, caused by subcutaneous haemorrhaging and exophthalmos are commonly present. Different diagnostic methods have been used for Y. ruckeri, including culturing, serological, biochemical tests, histopathological studies and molecular techniques. This review summarizes the past, present and future state of yersiniosis with emphasis on status of this disese in Iran. Also, some criteria in diagnosis, control and prevention of ERM were discussed.

In present study the effect of dietary inclusion of equal amounts of four traditional medicines; Matricaria chamomilla L, Zataria multiflora L, Mentha piperita L and Terminalia chebulo L on growth performance and digestive enzymes activity in Litopenaeus vannamei was investigated. Two diets, including a control basal diet and an experimental diet with 30 g kg-1 herbal mixture supplementation were prepared. Juveniles (with average weight of 2.63±0.11 g) were fed control and supplemented diet for 60 days. At the end of the experiment, shrimp fed the experimental diet showed significant increase in SGR, WGR, compared with those of the control group. Shrimp fed with herbal mixture supplementation revealed significantly higher lipase, protease and amylase activities as compared with the control group in 60 days. The results indicated that using equal mixtures of four medicinal plants in L. vannamei diets can improve the growth parameters and digestive enzyme activities.

Population structure and growth of Mossul bleak, Alburnus mossulensis, a native species of cyprinids in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. For this purpose, 543 speciments (353 females, 159 males and 31 immature) were caught using seine net (5 mm mesh size) and a cast net. Age groups of males and females were 0 to 5. The most frequent age group was 2 in both sexes. The sex ratio was 1M:2.2F (p0.05). The largest female was 16.80 cm in total length and 49.12 g in weight, while the largest male was 14.10 cm in total length and 28.19 g in body weight. The length-weight relationship was calculated as W = 0.0169L3.0355 (r2=0.95) for males, W=0.0061L 3.1751 (r2=0.98) for females and W=0.0066L3.139 (r2=0.99) for all fish (males, females and immature). Regression coefficient (b) based on Pauly test, was significantly different from 3 in females, but not in males (p

Protein banding pattern of eight snakeheads – Channa species viz., Channa striatus, Channa marulius, Channa punctatus, Channa diplogramme, Channa bleheri, Channa gachua, Channa stewartii and Channa aurantimaculata collected from different regions of India were used to study the phylogenetic relationship among them. The banding pattern from muscle protein indicated a unique profile for each species and the electrophoregrams showed similarities among the species studied. In the SDS-PAGE, a maximum of 12 protein bands were obtained for C. gachua followed by 11 for C. diplogramme and 10 for C. marulius whereas less number of bands were recorded for the remaining species. Molecular weight of the protein bands varied from 16 kDa - 232 kDa. UPGMA (Unweighted Pair Group Method with Arithmetic Mean) dendrogram revealed that the phylogenetic relationship was very close among C. aurantimaculata and C. bleheri and also between C. gachua and C. stewarti.

Anchovy fillets that had undergone osmotic dehydration and response surface methodology (RSM) were used to determine the influence and optimal values of the process variables. Also the optimal processing conditions were determined in order to reduce the solid gain and water loss ratio (SG/WL) and firmnessfor the anchovy fillets. A three-levelcentral composite rotatabledesign (CCRD) involving the variables such as temperature (20-45oC), processing time (19-221 min)and salt concentration (12-28%,w/w) were developed for this purpose. Data obtained from RSM analysis on the SG/WL and texture property of anchovy fillets were subjected to the analysis of variance (ANOVA) and they were analyzed using a second-order polynomial equation which resulted in the optimum process levels.

Advantages of pelleted feeds in terms of storage, transportation and lower costs compared to natural fresh feed justified the replacement of artificial feeds instead of natural ones partially on maturation performances. This study comprised nine treatments (with three replications) including control treatment: polychaete worm (Perinereis nuntia), Squid and calf liver (natural feed); T1: pellet feed with 50% crude protein and 8% crude lipid Perinereis nuntia, Squid and calf liver; T2: pellet feed with 50% crude protein and 10% crude lipid Perinereis nuntia, Squid and calf liver; T3: pellet feed with 40% crude protein and 10% crude lipid Perinereis nuntia, Squid and calf liver; T4: pellet feed with 40% crude protein and 8% crude lipid Perinereis nuntia, Squid and calf liver Perinereis nuntia; T5: pellet feed with 50% crude protein and 10% crude lipid; T6: pellet feed with 50% crude protein and 8% crude lipid; T7: pellet feed with 40% crude protein and 10% crude lipid; T8: pellet feed with 40% crude protein and 8% crude lipid. In treatments 1, 2, 3 and 4, 50% of the natural diets were removed and pellet foods used instead. The amount of pellet feeds that given daily, was 3.5% of shrimp broodstock biomass. In treatments 5, 6, 7 and 8, the amount of pellet feeds that given daily was 7.5% daily. Feeding was done 4 times a day. GSI in the control (3.23%), treatment 3 (3.20%) and treatment 6 (3.02%) were significantly higher than that in the other treatments (p0.05). Survival rate in the treatment 8 (26.66%) was significantly lower than other treatments (p

The present study was conducted to evaluate the effect of 20 d starvation on growth, survival, histomorphology and ultrastructure changes in the digestive system of juvenile red swamp crayfish (Procambarus clarkii). Juveniles were divided into two groups: a food-deprived group and a control group at 9 day after hatch (DAH). Individuals were sampled at 14, 20, 29 DAH. During the 20 d fasting period, the mean body weight and total body length of crayfish fluctuated around 10.17 mg and 8.12mm respectively, and the mortality was zero. Histomorphological changes of digestive system were observed in the food-deprived group after 20 days of starvation: the esophagus and stomach walls were thinning, the epithelium atrophied to cuboidal, nuclei were darker and smaller, and nucleolus was difficult to observe; the midgut and hindgut showed wider volume, thinning wall, atrophied epithelial and muscularis and shorter ridges; and hepatopancreas tubule lumens were wider, the lipid droplets in R-cells were smaller and less, and the quantity of typical B-cells decreased. Changes in the ultrastructure of starved crayfish were also observed: the mitochondria of midgut epithelium and R-cells were swollen and vacuolated, and the ridges of which were fractured and reduced. In addition, the electron density of cytoplasmic matrix of R-cells decreased, and the quantity of glycogen granules and lipids also decreased. Changes in the ultrastructure of B-cells were similar to those of R-cells. Though degeneration in histological structure and function of digestive organs were obvious during starvation, juvenile P. clarkii was able to endure a relative long-term starvation.

In this study, Aloe vera extract was used to evaluate its effects on hematological and immune parameters of Siberian sturgeon (Acipenser baerii). A total of 360 Siberian sturgeon weighing on average 10.95±0.04 g were randomly distributed in four treatments including a control group and three experimental groups (each with three replications). A. vera extract powder at the rate of 0.5%, 1% and 1.5% were added to the food. The fish were fed for 60 days in fiberglass tanks. At the end of the first and second months of breeding, the necessary samplings for hematological studies were done. The physicochemical parameters of water were recorded every day. The results showed significant differences (p

In this research, the nutritional effects of Sargassum ilicifolium Chabahar Bay, Oman Sea, on cholesterol levels of white-leg shrimp (Litopenaeus vannamei) were studied. The seaweed was collected from coastal areas, rinsed, dried, powdered and the nutritional values were measured in the laboratory. A part of protein resources of shrimp feed replaced with seaweed powder in four treatments (D: as control without any replacement) C: with 5%, B: 10 % and A: 15% seaweed replacement, each with three replicates in order to obtain isonitrogenus 33% CP., and Isocaloric (13% fat and 15% carbohydrate) feed. Dried diets were used according to the daily need of shrimp, calculated after each 10 day biometry. Water stability and absorption capacity of the pellets in sea water were measured and compared statistically. Juvenile shrimps (Initial body weight=3 g) were acclimated for one week under hatchery conditions and were fed 3-5% of their body weight. Abiotic parameters, weight and length biometry were measured on day two and day 10, respectively. After 45 days final biometry, body analysis were measured, and muscle colorimeter were conducted using HPLC. There were no significant differences (p>0.05) between body lipid among treatments, but cholesterol content (mg/100gWW) showed significant differences (p

The aim of the present study was to detect polymorphism in Insulin like growth factor-I (IGF-I) gene of beluga (Huso huso) fish using PCR-SSCP technique and also investigation of its association with growth traits (condition factor, body length and weight). A total of 150 specimens of beluga were randomly selected and DNA was isolated from caudal fin using modified salting out method. Then two fragments of 171 and 362 bp from 5'-UTR and 3'-UTR regions of IGF-I gene were amplified, respectively. Genotyping of individuals by SSCP technique showed five banding patterns of A, B, C, D and E for 5'-UTR region with the frequencies of 29.2, 0.76, 16.92, 51.53 and 10% respectively in one year-old and three banding patterns of A, C and D with the frequency of 45, 10 and 45% for two year-old fish. Also three banding patterns (A, B and C) were seen for 3'-UTR region with the frequency of 62.3, 27.69 and 10.76% in one-year-old and 20, 60 and 20% in two year-old fish. The A banding pattern in 3'-UTR and D banding pattern in 5'-UTR sites were the most frequent pattern in the studied beluga population. The association analysis using SAS statistical software indicated no significant association between observed banding patterns and growth traits (body length, weight, and condition factor) in beluga. Considering the important role of IGF-I as a probable candidate gene affecting growth related traits, these marker sites should be studied more in larger sample sizes and also in other regions of the gene.

Aquatic organisms present, not only simple sources of accumulated metal, but can interact with metals, altering their toxicity. Due to exposition of biosphere with metals, organisms have developed various defense mechanisms to protect themselves against adverse effects of these ions and their compounds. Metallothionein (MT) is one of that which represents a critical mechanism for detoxification of metals.The sterlet (Acipenser ruthenus) is a bottom feeding sturgeon specie and because the fish are dependent on invertebrate species for food throughout their life cycle, the sterlet could be a good indicator of the quality of the state of water ecosystem. Addition of copper to water leads to the induction of MT. The present study analyzed MTgene that was excreted from the liver of sterlet exposed to sub-lethal copper concentrations (0.075 mgL-1). To begin to elucidate the molecular mechanism(s) of sensitivity of sturgeons to metals, a RNA encoding MT was purified from livers of sterlet, then a cDNA was synthesized and the MTgene was amplified. The primary structure of sterlet metallothionein (S-MT) contained 20 cysteine residues, which is the same as MTs of teleost fishes. However, the primary structure of S-MT contained 63 amino acids, which is longer than any MT identified in teleost fishes but similar to Lake sturgeon and White sturgeon. The complete nucleotide sequence of the S-MTgene has been detected. We have determined the structure of the fish copper-binding protein by DNA sequence analysis of the gene.

The present study was carried out to examine 6 plants including aquatic and terrestrial plants on food preference and growth of grass carp. 7 experimental treatments with three replicates were considered. The experimental treatments were ponds containing T1: M. spicatum, T2: C. demersum, T3: A. filiculoides, T4: L. minor, T5: C. dactylon, T6: M. sativa and T7: M. Spicatum C. demersum A. filiculoides L. minor C. dactylon M. sativa. 12 grass carps (20 g) were added to each experimental pond. After 5 months, the fish body composition was assessed. According to results, the higher values of fish weight gain rate were obtained in treatments T4 (3.13 g), T6 (2.93 g) and T1 (2.95 g) compared to other experimental groups (p

The brine shrimp, Artemia spp., is widely used in ecotoxicological research as a biological index. In the present study, aquatic stability and acute toxic effects of TiO2, CuO and ZnO nanoparticles (NPs) on Artemia franciscana were investigated. Acute exposure was conducted in sea water with different concentrations of selected nanoparticles at 24h, 48h, 72h and 96h. The mortality rate of A. francisca increased significantly with increasing concentrations and duration of exposure of all NPs. The toxicity pattern of metal oxides to A. francisscana was as follows: CuO>TiO2>ZnO. Our results point to the fact that both TiO2 and ZnO NPs exhibited moderate toxicity to Artemia larvae in 24h as compared with CuO, regardless of their size and concentrations.

This trawl survey was carried out during 2013 for the stock assessment of families Haemulids, Nemipterids and Ariids in the Oman Sea. Sampling was carried out at five different stratum and depths. The highest value of CPUA of Haemulidae was estimated for Pomadasys stridens in “B” stratum (885.78 kg nm-2), for Pomadasys kaakan at depths of 10-20 m (330.35 kg nm-2), and for Nemipteridae it was estimated for Nemipterus japonicus in “D” stratum (1042.31 kg nm-2) at 30-50 m depths (1734.97 kg nm-2), and for Ariidae, it was estimated for Netuma thalassina in the stratum B (752.64 kg nm-2) at 20-30 m depths (428.33 kg nm-2). The highest biomass for Haemulidae was estimated in stratum B (320.53 ton) at 50-100 m depths (282.98 tons), and for Nemipteridae in “D” stratum (559.72 tons) and at depths of 30-50 m (604.04 tons), and for Ariidae it was estimated in “B” stratum (272.35 tons) and at 50-100 m depths (255.12 ton). Based on the results obtained, the highest species diversity for Haemulids was in “A” stratum at depths less than 50 m, while for Nemipterids it was similar in the total study area and different depth layers. Highest species diversity for Ariids were found in “A” and “D” strata at depth layers of 10-20 m and 30-50 m, respectively. In light of the fact that fishing efforts decreased during these years, our results illustrate that CPUA and biomass have ascending trends which indicate the relative stability of the stocks of these families.

The present work was conducted to investigate the chemical composition (amino acid, mineral content, and lipid profile) of bones from three different Iranian pelagic fish species. The biochemical composition of Sardinella gibbosa, Clupeonella engrauliformis and Stolephorus indicus bones captured from the Iranian Ocean (the Oman Sea and Caspian Sea) were determined. The analysis of amino acids and fatty acid profiles was done by HPLC and GC and also analysis of minerals was done by means of flame atomic emission spectrophotometry. The least amount of mono unsaturated fatty acids was observed in C. engrauliformis (p

Reproductive status of Alburnus chalcoides adults from Anzali Wetland was investigated by histological examination of gonads, assessment of sex steroids (i.e. Progesterone (P), Estradiol-17ß (E2), Testosterone (T)) and reproductive indices (i.e. absolute fecundity, oocyte diameter, hepatosomatic index (%HSI) and gonadosomatic index (%GSI)). Totally, 42 females and 16 males were captured during March to May 2014 by gill net and divided into two age groups including 2 year olds and 3 year olds. In each age group, fish were classified into two groups depending on maturation stage i.e. matured and maturing fish. According to the results obtained, in each age group, there were no significant differences between matured and maturing males and females in terms of absolute fecundity (p>0.05). In each age group, oocyte diameter was higher in matured fish than in maturing individuals (p