Iranian Journal of Fisheries Sciences
Volume:13 Issue: 4, Oct 2014

Sea cucumber is presented as potential marine source of antimicrobial compounds. The purpose of this study is to evaluate antifungal effects of sea cucumber, Holothuria leucospilota, extracts on Aspergillus niger and Candida albicans. Methanol and chloroform extracts of the body wall, gonad and intestine of sea cucumber, H. leucospilota, collected from Persian Gulf, were evaluated for their antifungal activity against A.niger and C.albicans. The activity was determined using serial dilution method. Antifungal activity, minimum inhibitory concentration and minimum fungicidal concentration were evaluated by the different concentrations. Results showed that each of the extracts had antifungal effect at specified concentrations on the A.niger. All examined concentrations of Gonad methanol and intestine chloroform extracts had no inhibitory effect on C.albicans. Chloroform extracts of gonad and intestine had more fungicidal effect against A.Niger compared with C.albicans. Gonad chloroform extracts showed more fungicidal effect on the C.albicans at concentrations of 2.5, 5 and 10 mg/ml. Sea cucumber extract can be considered as an antifungal agent in various industries such as medicine and pharmaceutical industry.

The aim of the present study was to evaluate the impacts of diets supplemented with different lipid sources on growth performance, body composition, fatty acid profile, and hepatic antioxidant enzyme activity of juvenile black sea bream, Acanthopagrus schlegeli (initial mean weight, 1.1±0.02g). Four isonitrogenous and isolipidic diets were formulated with either fish oil (FO), soybean oil (SO), linseed oil (LO) or a mixture of SO and LO (SO+LO). The results showed that survival, weight gain, feed efficiency and protein efficiency ratios of black sea bream were not affected by dietary lipid sources (p>0.05). Liver and muscle of fish fed the SO diet had high concentration of linoleic acid, while those of fish fed the LO diet were high in linolenic acid. Liver and muscle of fish fed the FO diet had significantly (p<0.05) higher levels of eicosapentaenoic acid and docosahexaenoic acid, compared to fishes fed the SO and LO diets. Superoxide dismutase and glutathione peroxidase enzymes activities in liver of black sea bream were not influenced by dietary lipid sources. Our findings suggest that SO and/or LO can be used as a substitute for FO in black sea bream diets without adverse effects on growth performance and antioxidant enzyme activity, when the essential fatty acid requirements are present in diets for black sea bream.

Age, growth and reproduction were investigated for Chondrostoma regium, collected monthly (November 2007- August 2008) from the Dimeh Spring region, Zayandeh Roud River, Iran. The maximum age of collected female and male fish were estimated based on scale increments as five and four years respectively. Von Bertalanffy growth equations were calculated as L_t=246[1-e^(-0.206(t-0.034))], W_t=163.29〖[1-e^(-0.206(t-0.034))]〗^2.77 for females and L_t=253.1[1-e^(-0.206(t-0.175))], W_t=188.25〖[1-e^(-0.206(t-0.175))]〗^2.99 for males. Size ranges of the male and female specimens were almost similar. The fork length range for females was 10.5-18.0 cm and 10.7-19.7 cm for males; and the weight range was 15.7-85.4 g in females, and 14.5-88.5 g in males. The female-male ratio was 1.8:1 (p<0.05), and for both sexes gonadal development and sexual maturity occurred in the second year of their life. Length-weight relationships revealed isometric growth pattern for males and a negative allometric growth for females. Monthly data of Gonadosomatic Index, and ovary condition suggested that spawning occurred during May and June. The mean absolute and relative fecundity was calculated as 2429±1512 (eggs/female) and 78.118.7 (egg/g), respectively, and fecundity was significantly correlated with both body weight (r2=0.90) and fork length and (r2=0.84).

Sponges, which constitute the phylum Porifera, are the most primitive of the multicellular animals, among all marine organisms screened. Marine sponges produce the largest number of structurally diversified natural products. In this study we investigated in vitro antimicrobial activity of Ircinia mutans collected from the Kish Island in the Persian Gulf against strains of bacteria Escherichia coli (ATCC 15224), Pseudomonas aeruginosa (ATCC 25619), Staphylococcus aureus (ATCC 1764), and Bacillus subtilis spizizenii (ATCC 6633). Diethyl etter, methanol and aqueous extracts of sponge were evaluated by using the Bacterial Broth Dilution Method. The results showed that the aqueous extracts didn’t have any antibacterial activity. Minimum Inhibitory Concentrations (MIC) of the winter diethyl etter extract was 2 mg/ml for E.coli and 20 mg/ml for P. aeruginosa, whereas the summer diethyl etter extract and both of methanol extracts did not show any activity. The MIC and MBC (Minimum Bacterial Concentration) of summer diethyl etter extracts were 2 mg/ml and 3mg/ml against S.aureus; and 5mg/ml and 10mg/ml when tested on B. subtilis. The MIC and MBC of winter diethyl etter extracts were measured as 1.5 mg/ml and 2mg/ml against S. aurous; and 5mg/ml and 10mg/ml when examined on B.subtilis. Summer and winter methanol and aqueous extracts of I.mutans did not show any activity against these bacteria. Therefore secondary metabolite solutions in diethyl etter contain components with antibacterial properties and can be used as antibiotics products.

To determine the composition and abundance of zooplankton assemblages in Eğirdir Lake-Turkey, monthly surveys were conducted from January to December 2010 at four stations. A total of 65 major zooplankton species were identified. Rotifera was the most abundant taxon dominated mainly by the species Polyarthra dolichoptera and Keratella cochlearis. Rotifers were recorded at the maximum abundance of 5.609 individuals/L in October at the fourth station, and their highest mean abundance was 783±1358 individuals/L at the third station. There was a highly significant difference (p<0.001) that October was differentiated from other sampling months with the highest rotifera and zooplanktonic abundance. Although the mean total zooplankton abundance at four stations was changed between 357±429 and 841±1375 individuals/L, no significant difference was recorded amongst sampling statitons in view point of abundance variation (p>0.05). The zooplankton abundance comprised: Rotifera = 89.62 %; Cladocera = 7.78 % and; Copepoda = 2.60 %. Newly reported species from the lake were: the rotifers Conochilus dossuarius, Euchlanis dilatata, Trichotria tetractis, Trichocerca bicristata, Trichocerca capucina, Trichocerca cylindrica, Lecane stenroosi and Lepadella patella, and the cladocerans Biapertura affinis, Coronatella rectangula, Alona qaudrangularis, Alona guttata, Alonella excisa, Alonella nana, Disparalona rostrata, IIyocryptus sordidus, Acroperus harpae, Monospilus dispar and Camptocercus uncinatus. The annual mean concentration of chlorophyll-a was 3.0±0.2 mg/m3. According to the Carlson’s trophic state index, Eğirdir Lake is mesotrophic–eutrophic. A Brachionus: Trichocerca quotient value of 1.25 was calculated, clearly indicating that the lake is mesotrophic. Zooplankton composition data were analyzed using Shannon’s diversity index and ranged from 0.90–1.77.

Infectious Pancreatic Necrosis Virus (IPNV) is a member of the family Birnaviridae that has been linked to high mortalities in salmonids. Bacterial based systems as live vectors for the delivery of heterologous antigens offer a number of advantages as vaccination strategies. VP2 is a structural viral protein of IPNV with immunogenicity effects. In this study IPNV was isolated from diseased fry of rainbow trout Oncorhynchus mykiss (Walbaum) using CHSE-214. Then an expression vector was constructed for expression of viral protein VP2. The designed vector was constructed based upon pET-26b (+) with T7 promoter. A fragment containing the full length of the VP2 gene of Iranian Sp strain was amplified by PCR using genomic RNA of IPNV as template and cloned inpET-26b(+) plasmid. Recombinant structural viral protein VP2 was expressed as a soluble, N-terminal PelB fusion protein and secreted into the periplasmic space of Escherichia coli BL21(DE3) and Rosetta (DE3). The glucose, Isopropyl-β-D- thiogalactopyranoside (IPTG) was used as a chemical inducer for rVP2 production in 37º C. The rVP2 was extracted from the periplasm by osmotic shock treatment. The presence of gene in bacterial system of E. coli was confirmed by gel electrophoresis technique. The constructed vector could efficiently express the rVP2 into the periplasmic space of E. coli. The successful cloning and expression of the structural viral protein gene into E. coli can be used for developing a useful and safe vaccine to control IPNV infection in Iranian fish industry.

The present study was carried out to investigate the status of health and disease, and their impact on shrimp broodstock (Litopenaeus vannamei) in Khouzestan Province (Choeibde Area) in the south of Iran. From March 2012 until April 2013, about 140 broodstock and 5000 postlarvae (PLs) were collected from hatcheries and grow out farms. Clinical signs of samples were documented in take history forms and then the samples were transported to Iranian South Aquaculture Institute (Ahvaz). Bacterial and fungal studies were carried out on hemolymph, hepatopancreas and gill tissue and then the shrimps were preserved in Davidson Fixative for histopathology. A part of uropods was also preserved in ethyl alcohol for PCR study and detecting three viruses, WSSV, TSV and IMNV. A part of PLs was also preserved in ethyl alcohol for PCR and the remaining was preserved in Davidson Fixative for histopathology. The results showed that 5 bacteria consisting of Vibrio alginolyticus, V. proteolyticus, V. mimicus, A. hydrophila and Plesiomonas shigelloides and one fungi Aspergillus fumigatus were identified. The results of PCR exhibited that the broodstock was free of the three viruses and the PL was infected with WSSV. In histopathology some tissues showed the effects of Vibrio infection in different organs such as gill and midgut, and the infection of PL tissues showed the Cowdry type A inclusion bodies in WSSV. Two specific signs of abnormality were also exhibited in histopathology that we call them Pseudo inclusion and Reolike particles and we need to conduct a new study to clarify detailed information about these finding. This finding can be used for assessing the health of shrimp culture and prevention of disease in broodstock in Iran.

During a survey of Gahar Lake and Gahar River from 2008 to 2009 some specimen obtained by seasonal sampling in 6 stations, 3 stations in the lake and 3 stations in the river. Three different methods were used for sampling, gill net and hook in the lake and electrofishing in the river. Due to the results 3 species from 2 families in Gahar Lake and 12 species form 3 families in Gahar River were identified. Most of the fish species belonged to Cyprinidae and Salmonidae families. Distribution and abundance of species were recognized. Oncorhynchus mykiss in Gahar Lake and Capoeta damascina in Gahar River had the most abundance.

Ayu (Plecoglossus altivelis), one kinds of valuable cultured fish species, show almost no morphological difference between male and female until sexual maturity. Here, we report the identification of sex-linked markers for the ayu, based on Amplified Fragment Length Polymorphism (AFLP) generated from cultured fish (15 males and 15 females) by using 63 different primer combinations. Genomic fragments (n = 3733) were produced with a mean frequency of 59 bands per primer pair. A male-specific of 139 base pair band was amplified and converted to a sequence-characterized amplified region (SCAR marker) designated as Ayu102. Six distinct genomic fragments were produced in 12 wild samples (6 males and 6 females). The fragments designated a, b, c, d, and e were detected only in males, and one fragment (f) was detected in both genders. Nucleotide sequence analysis showed that fragments e and f were 96.67% identical. Ayu102 marker was detected in 45-d-old larvae, in both cultured and wild fish populations, and in offsprings generated by gynogenesis. Fragment e was detected in all males, and in only 6.7% of females in cultured fish. Data suggest that Ayu102 marker is a male-specific marker linked to the sex-determining locus of the male ayu and can be used for gender identification.

Taking into account the high potential of cyanobacteria to tolerate salinity stress, researches have evaluated the morphological and physiological behavior of these microorganisms in recent years. This study is conducted to investigate the impact of different concentrations of NaCl on the morphological and physiological traits of Nostoc sp. ISC 101. Biometrical and morphological observations are carried out by light and scanning electron microscopy. Results indicated that vegetative cells and heterocysts were wider in control treatment in comparison with samples under different amounts of salinity. Akinete formation began in 3% NaCl and reached to highest level in 5%. The relative degeneration of structure of the cells in 5% salt was demonstrated. According to physiological impresses of salt it was found that growth rate decreased with increasing salinity. Total chlorophyll content stimulated in 1% salinity, but in the higher concentration it decreased vice versa. The rate of APC, PE, PC increased in 1% salinity, although in high level concentration they would be diminished. Photosynthesis rate was also decreased with increasing salinity but it was stimulated slightly in 1% NaCl. All in consequence, despite of acclimation of this strain to marine environment, not much tolerance was seen in the mentioned treatments, and increasing salinity to upper than 1% NaCl had destructive effects, and cyanobacterium maintained its growth rate at slightly saline environments.

To identify Kraft liquor effects on spermatogenesis and sperm motility of Caspian kutums by using in vitro culture, the fish testis was incubated with 5, 10 and 15 % (V/V) of liquor for 3 and 6 days. The percentage of motile spermatozoa and its total duration were also measured. Adverse effects on testicular cells were more apparent with the increase of liquor concentrations. The mean size of spermatogonia and spermatocytes decreased significantly (p<0.001) in dose-dependent manner compared to controls. With the increase of concentration, the number of spermatocytes and spermatids decreased (p<0.001) but the number of spermatogonia, increased (p< 0.05). The increase of liquor concentration showed a significantly decrease of percentage of motile spermatozoa and total duration of spermatozoa (p<0.05); but there was no significant difference in most treatments (p>0.05). This study showed the detrimental effects of low levels of kraft liquor on testicular development and sperm quality in the kutums.

This study was conducted to evaluate the effects of dietary levels of vitamins E (25, 30 and 35 mg kg-1), Folic Acid (1.5, 2 and 2.5 mg kg-1) and their combination on the growth performance, hematological and immunological parameters of rainbow trout, Oncorhynchus mykiss. Each diet was fed to rainbow trout in triplicate to apparent satiation four times daily for 8 weeks. At the end of the feeding trial, the final body weight (FBW), total length (TL), feed conversion ratio (FCR), specific growth rate (SGR) and survival rate were significantly affected by treatments and the fish fed with the diet containing 35 mg kg-1 vitamin E plus 2.5 mg kg-1 of folic acid had higher values than those fish fed with the other diets. The results also indicated that hematocrit (Ht), mean corpuscular volume (MCV) mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were significantly influenced by the treatments. Lysozyme and immunoglobulin (IgM) concentrations were significantly influenced by the dietary treatments, fish fed with the diet supplemented with 30 mg kg-1 of vitamin E plus 2 mg kg-1 of folic acid and unsupplemented diet had higher concentrations than those fish fed with the other diets. The findings of this study suggested that trout requires 35 mg kg-1 vitamin E and 2.5 mg kg-1 folic acid for it’s normal growth and physiology.

The aim of this research was to study the occurrence of Vibrio spp., Aeromonas hydrophila, Escherichia coli and Campylobacter spp. in crayfish from Azerbaijan Province using culture method and PCR assay. A total of 55 isolates were collected from 97 studied samples. Vibrio spp., A. hydrophila, E. coli and Campylobacter spp. were detected in 26 samples (26.8%), 12 samples (12.3%), 15 samples (15.46%) and 2 samples (2.06%), respectively. Among Vibrio isolates, Vibrio vulnificus (11.3%) was the species most frequently detected followed by V. harveyi (7.2%), V. alginolyticus (2.06%) and V. mimicus (1.03%). The results of this study indicated that crayfish from the studied area contain pathogens relevant to public health.

Monthly sampling of speckled shrimp was conducted by bottom trawl in the Iskenderun Bay between November 2009 and October 2010. There was a linear relationship between carapace length and total length in males and females (TL = -0.112 + 0.2294*CL; R2 = 0.8298, n = 327) for males, (TL = -0.3918 + 0.2731 * CL; R2 = 0.8919, n = 457) for females, and (TL = -0.378 + 0.2684 * CL; R2=0.8492, n=784) for total individuals. Total length-weight relationships were W=0.0135*TL2.7817 for males, W= 0.0115*TL2.8535 for females, and W=0.0109*TL2.8108 for total individuals. The von Bertalanffy growth constants in length was TL= 162.75mm, K = 1.39 year–1, t0 = -0.0604 year for males; TL= 178.40mm, K = 1.51 year-1, t0 = -0.780 year for females; and TL= 174.14mm, K = 1.47 year-1, t0 = -0.0721 year for total individuals. In this study, the total (Z), natural (M) and fishing (F) mortality coefficient and exploitation rates (E) were determined as 5.39 year-1, 2.39 year-1, 3.00 year-1 and E=0.56 year-1, respectively for all of the obtained individuals.

The aim of this study was to determine the selectivity of monofilament gillnets with different mesh size for silver crucian carp in Eğirdir Lake. In this study, it was investigated that the selectivity of monofilament gillnets with nominal mesh size (stretched) with 32, 40, 50, 60, 70, 80, 90 mm and trammel nets with 100, 110, 120, 130, 140, 150 mm for catching of silver crucian carp. Fieldwork was carried out in two different station of Eğirdir Lake, between January-2010 and December-2010 with a three-month period and a total of 4 catching operations. (Share Each Length class Catch Total) (SELECT) method was used to determine the selectivity parameters. In the experiments 1562 silver crucian carp species in ranges of the length between 7.9 cm- 37.0 cm were caught. As a result of calculations made according to the bi-modal model which gave the lowest deviation, for gill nets optimum length (cm) was found as 8.77, 10.96, 13.70, 16.44, 19.18, 21.92, 24.66 for 32, 40, 50, 60, 70, 80, 90 mm mesh size; for trammel nets optimum length (cm) was found to be 24.90, 27.39, 29.88, 32.37, 34.86 for 100, 110, 120, 130 and 140 mm mesh size monofilament trammel nets, respectively.

Induction of heat shock proteins (hsps) is considered as an important protective, ecophysiologically adaptive, and genetically conserved response to environmental stress in all organisms. The effects of exposure to sublethal doses of CdCl2 (0.05, 0.1 and 0.2 LC50) during 14 days on mRNA-hsp70 expression in liver and gillwere investigated in juveniles of Persian sturgeon (Acipenser persicus). First, a fragment of 726 nucleotides coding for hsp70 was cloned from the liver. The result showed that in both study tissues, gill and liver, the relative mRNA-hsp70 expression level significantly increased (p≤0.05) on all study days compared to control group. Relative mRNA-hsp70 showed a clear time- dependent response in both tissues following the exposure to CdCl2. A significant increase (p≤0.05) was observed on the second day and then decreased up to day 7 of the exposure and increase level of mRNA-hsp70 expression was observed on day 14. The same trends were observed on all the study doses (0.05, 0.1 and 0.2 LC50), in both examined tissues. Although in this study up expression of hsp70 was common to both the gill and the liver, it was significantly (p≤0.05) expressed more in the liver than the gill. At higher dose, the increase level of mRNA expression was found to be more than that of other experimental doses in all study days. The result revealed that these proteins can be used as a promising biomarker for Cd contamination in this species.

Plant proteins are plausible fishmeal substitutes but are deficient in some essential amino acids (EAA) like lysine and methionine. Combination of different plant proteins with complimentary EAA could be useful alternative. Bambaranut (Voandzeia subterranea) contains high amount of lysine while methionine is in sesame seed (Sesamum indicum). This experiment tested effects of combining sesame seed meal (SSM) and bambaranut meal (BNM), on juvenile African catfish Clarias gariepinus. Inclusion levels (%) of SSM: BNM in four novel diets were, feed 1 (F1) 0:35, feed 2 (F2) 11.7:23.3, feed 3 (F3) 23.3:11.7, feed 4 (F4) 35:0. Catfish (initial weight ± SD 11.7 ± 0.56 g) were stocked in four replicate 15L glass aquaria at 20 fish tank-1. Final weight and specific growth rate (SGR) were significantly higher for catfish fed F2, F3 and F4 (SGR treatment means varying between 8.34 - 8.67 % day-1) than for F1 (7.60 ± 0.27 % day-1 and feed conversion ratio (FCR) significantly lower for F2, F3 and F4 (0.71-0.73) than for F1 (0.8 ± 0.04). Catfish fed F1 had higher body water and lower lipid and protein content than fish in the other treatments. Protein efficiency ratio was similarly higher for catfish fed F2, F3, F4 than F2 and F1. The cost kg-1 of diet production increased with inclusion of SSM justifying reduction of SSM in the mixture. Results indicate that SSM and BNM alone or in combination are good plant proteins. Diets of SSM-BNM-FM were similar to SSM-FM. Inclusions of SSM increased body lipid than BNM.

Induction of triploidy is one of the biotechnological methods in aquaculture used for genetic manipulation. It refers to a state where organisms have three complete sets of chromosomes instead of two and can result in sterility. Caffeine treatment that is safe and inexpensive, serve to induce triploidy in catfish. To suppress the second meiotic division, fertilized eggs were exposed to three different concentrations (5, 10 and 15 mM) of caffeine solution for 20 min beginning at 3 min after fertilization. After that, the eggs were incubated at ambient temperature until hatching. The induction of triploidy in fry was determined for three concentrations of caffeine by means of flow-cytometric analysis. The lowest rate of triploidy (20.40 ± 1.13%) was obtained in the group treated with 5 mM caffeine and the highest (69.10 ± 2.18%) in the group treated with 15 mM caffeine. Our results suggest that caffeine can be used to induce triploidy in catfish.

White spot syndrome virus (WSSV), the causative virus of disease, is found in most shrimp farming areas in Iran, and it cause large economic losses to the shrimp farming industry. Shrimp aquaculture is an important industry in Iran and plays an important role in aquaculture production. The shrimp production in 2012 was more than 12000 metric tonnes and it is estimated it will reach 20000 tonnes in 2013.White spot syndrome virus is highly virulent in shrimp farms and can spread quickly and - cause up to 100% mortality within 3-7 days. The virus is a very large, enveloped, double stranded DNA (ds DNA) and assigned by ICTV to a new genus Whispovirus and belong to Nimaviridae family. In Iran WSSV first appeared in Khuzestan Province in the south of Iran and later on it appeared in other provinces such as Bushehr, and Sistan and Baluchestan. The aim of this review is to give current information of WSSV in Iran, host ranges, carriers, biology, clinical signs, histopathology, PCR, with emphasis on the effects of WSSV in shrimp aquaculture.

This study investigated the effects of mate switching on the reproductive performance of the severum cichlid, Herosseverus, by advancing the egg and larval production in hatcheries. Two reproductive tactic treatments of “monogamous pair” and “mate switching” were used for evaluating 4 reproductive traits of egg production, hatching rate, spawning intervals, and starvation tolerance of the larvae in 6 spawning activities. The number of eggs was not significantly different between the two reproductive tactic treatments in the 6 spawning activities, but the spawning intervals, hatching rate, and survival activity index were all significantly different. Daily average egg and larval production in the mate switching treatment were estimated to be 87.3 eggs and 43.1 larvae per pair of fish, respectively, which was 2.89 times and 1.99 times of those in the monogamous pair treatment, who produced about 30.2 eggs and 21.6 larvae per pair. Our results clearly showed that the reproductive tactic of mate switching is a suitable method for increasing the egg and larval production rate of the severum cichlid.

Along the plant ingredients, rendered animal protein sources such as blood meal, meat and bone meal and poultry by-product meal have potential to be replaced by fishmeal in rainbow trout feed. Therefore, the main objective of the present study is to determine the effect of full replacement of fishmeal by poultry by-products meal (PBM) on fish performance, nutrient digestibility and also liver characteristics in rainbow trout. Four experimental diets were formulated to contain graded levels of PBM at 0 (control diet), 33 (PBM33), 66 (PBM66) or 100% (PBM100), respectively. The four treatments were randomly assigned to each of 12 tanks, having three replicates for each treatment. Rainbow trout juveniles with an average initial weight of 50±0.42g were reared for two months. The fish gained lower weight and specific growth rate at PBM 66% and 100%. FCR was recorded larger for rainbow trout feeding on PBM 66% and 100% in comparison to PBM 33% and control diets (p<0.05). The whole exchange of fishmeal by PBM (PBM100%) reduced dry matter, fat and protein digestibility (p<0.05). An increase in PBM content of diet also resulted in larger fat content of the fish liver (p<0.05). Body fat content reduced and moisture content increased by increasing PBM level (p<0.05). In conclusion, PBM can be included in rainbow trout feed as an alternative for fishmeal up to 33%. A larger fat content of liver at PBM 100% may indicate a negative impact of PBM on rainbow trout health at full replacement level.