فهرست مطالب

Iranian Journal of Fisheries Sciences
Volume:14 Issue: 1, Jan 2015

  • تاریخ انتشار: 1394/03/10
  • تعداد عناوین: 23
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  • M. Aminur Rahman *, R. Ara, S.M.N. Amin, A. Arshad Pages 1-14
    An experiment was undertaken to develop a suitable seed production technique for Sperata aor in captivity. Naturally produced fry of aor was reared at different densities in nine nursery ponds 0.012 ha in size with an average depth of 0.8 m each. Three stocking densities tested, each of which was triplicated. Fry of aor stocked at 100,000/ha was designated as treatment-1 (T1), 150,000/ha as treatment-2 (T2) and 200,000/ha as treatment-3 (T3). All stocked fry were from the same age group with mean length and weight of 1.78 ± 0.28 cm and 0.24 ± 0.05 g, respectively. Fry in all the treatments were fed with SABINCO nursery feed (32.06% crude protein) for the first 14 days and starter-I (31.53% crude protein) for days 15 to 56. Physico-chemical parameters and plankton population of pond water were within the optimal level being better in T1 than those in T2 and T3. Growth in terms of final weight and length, weight and length gain, specific growth rate, daily growth rate, and survival of fingerlings were significantly higher in T1 followed by T2 and T3. Food conversion rate was significantly lower in T1 than in T2 and T3. Significantly higher number of fingerlings was produced in T3 than those in T2 and T1. Despite this, consistently higher net benefits were achieved from T1 than from T2 and T3. This is the first time report that stocking of 100,000 fry/ha appears to be the most suitable density for rearing of aor fingerlings in nursery ponds.
    Keywords: Sperata aor, Fry, Stocking density, Fingerling, Growth, Production
  • A. Arshad *, T. Sofea, Z. Zamri, S.M.N. Amin, R. Ara Pages 15-26
    This study estimated the length-weight relationship, sex ratio and population parameters of mantis shrimp, Harpiosquilla harpax from the coastal waters of Pantai Remis, Perak, Malaysia between February 2012 and October 2012. Total length and weight of 804 specimens of H. harpax were measured and the sex ratio was 1: 0.83 (M: F). Males of H. harpax were dominant over the females throughout the study period. The value of relative growth coefficient (b) for H. harpax was 2.698 for males and 2.884 for females. For the length-weight relationship, the species exhibited negative allometric growth for males, females and combined sexes. The L∞ and K of H. harpax was 18.38 cm and 1.10 yr-1 for males; and 21.53 cm and 0.75 yr-1 for females. The growth performance index (φ') was calculated as 2.57 for males and 2.54 for females. Total mortality (Z), natural mortality and fishing mortality was found to be 4.084 yr-1, 2.247 yr-1 and 1.837 yr-1 for males; whereas 3.259 yr-1, 1.674 yr-1, 1.585 yr-1 for females, respectively. The recruitment pattern of the species was continuous throughout the year for males and females. The exploitation level (E) of H. harpax was estimated at 0.449 for males and 0.486 for females. It is revealed that the stock of H. harpax was very close to optimum level of exploitation (E = 0.50) in the coastal waters of Pantai Remis, Perak, Malaysia.
    Keywords: Harpiosquilla harpax, Condition factor, Sex ratio, Recruitment, Exploitation
  • A. Syahidah, C.R. Saad *, H.M. Daud, Y.M. Abdelhadi Pages 27-44
    Disease are recognized as one of the major constraint to sustainable animal production which can cause significant economic loss especially in aquaculture. Various chemotherapeutic agents have been traditionally used in the treatment and prevention of diseases in farmed fish but they are not recommended since improper and continuous use of antibiotics may lead to potential development of antibiotic resistant bacteria, environmental pollution and accumulation of toxic residues in fish. Therefore, scientists have intensified efforts to exploit natural products such as herbs in developing alternative dietary supplements that enhance growth performance, and health and immune system of cultured fish, as these products are inexpensive, safer, effective, and can be easily prepared and are biodegradable. This review discusses the findings from different studies related to the in-vitro and in-vivo applications of herbs and plant extracts or their combinations, in relation to appetite stimulator, growth promoter, antimicrobial, antiparasitic, antioxidant and immunostimulation in fish.
    Keywords: Aquaculture, Herbal extracts, Potential, Chemotherapeutics, Alternatives
  • S. Irannejad, A. Akhavan Sepahy *, M. A. Amoozegar, A. Tukmechi, A.A. Motallebi Moghanjoghi Pages 45-59
    Halophiles are in all three domains of life: Archaea, Bacteria and Eucarya. Halophilic microorganisms in addition to form major part of life biodiversity can have many biotechnological applications. The objective of this research is isolation and identification of halophilic bacteria from Urmia Lake in Iran and the study of its bacterial biodiversity. After sampling of brines from Urmia Lake from 10 stations and depth of approximately 30-50 cm, in April 2011 and transfer to the laboratory in the sterile conditions, samples were enriched and cultured on defined media, and incubated. After appearance of colonies, selected strains were studied based on morphology, physiology and biochemical characteristics. For phylogenetic identification, their genomic DNA were extracted and amplified by PCR technique. Therefore their sequences were determined by genetic experiment based on 16S rRNA gene sequence and their similarity were analysed in GenBank of EzTaxon database. Finally the phylogenetic tree was constructed. Studied strains belonged to three genera: Halomonas 50% (including H. andesensis LC6(T) [12.5%], H. gomseomensis M12(T) [12.5%], H. hydrothermalis Slthf2(T) [12.5%], H. boliviensis LC1(T) [6.25%] and H. janggokensis M24(T) [6.25%]), Salinivibrio 25% (including S.costicolasubsp. alcaliphilus DSM 16359(T) [18.75%] and S. sharmensis BAG(T) [6.25%]) and Idiomarina 25% (including I. loihiensis L2TR(T) [25%]).
    Keywords: Halophilic bacteria, Species diversity, Isolation, Phylogenetic, DNA analysis, Urmia Lake
  • C. Faggio, F. Fazio *, S. Marafioti, F. Arfuso, G. Piccione Pages 60-72
    The aim of this research was to investigate the effects of the oral administration of Gum Arabic on haematological and some oxidative stress markers in Mugil cephalus. For this purpose 60 mullet caught in Faro Lake (Italy), were acclimatized and fed with commercial diet for 20 days prior to the start of experiment, which lasted 15 days. After acclimatization, fish were randomly divided into two equal groups: control group was fed with commercial pellets. Haematological profile on whole blood and sera was assessed, reactive oxygen metabolites (d-ROMs), antioxidant barrier (OXY-ads) and thiol-antioxidant barrier (SHp) were immediately assessed by means of a UV spectrophotometer. Two-way repeated data analysis (ANOVA) showed significant changes only on Thrombocyte Count (TC). In the experimental group an increase in OXY-ads and SHp levels and a significant decrease of d-ROMs were observed after administration of GA.
    Keywords: Gum Arabic, Diet supplement, Haematological profile, Immuno, stimulant capacity, Oxidative stress, Mullet
  • S.H. Kim *, K.H. Lee, S.W. Park, D.G. Lee Pages 73-86
    We aimed to develop alternative fishing gear for catching the common octopus, to decrease the use of bait and operating costs in comparison to commercial net pots. A tubular-type pot was designed, and behavioral responses of the common octopus were experimentally monitored in tank and replicated 10 times to compare fishing performances between 300 experimental and 300 commercial net pots in the coastal sea of Gangjin, Korea. The behavioral responses under experimental conditions included emergence from the mud den, detection of the bait on the pot surface, and entry into the pot (toward the bait). The field experiment results indicate that numbers and weights of the catch during offshore fishing were 703 (56.0 kg) and 795 (86.3 kg) via tubular-type and net pots, respectively. The catch per unit effort (CPUE) for the number and weight of the tubular-type pot from 10 trials were 0.23 individuals/pot and 18.87 g/pot, respectively; and weight for the net pot were 0.27 individuals/pot and 28.77 g/pot, respectively. No significant difference was noted between the CPUE in catch number for tubular-type and net pots (Kruskal–Wallis test, p=0.305 > 0.05); however, the CPUE by weight was significantly higher using net pot than tubular-type pot (Kruskal–Wallis test, p= 0.01<0.05). The amount of bait used during the experimental period for the tubular-type pots were 1/3.4 less than that of the commercial net pot. Therefore, fishing operating cost for common octopus was reduced using tubular-type pot.
    Keywords: Fishing performance, Common octopus, Octopus minor, Pot, Fishing gear design
  • S. Bahadir Koca *, O.Y. Uzunmehmetoglu, B. Yazicioglu Pages 87-98
    The experiment was conducted to investigate the effects of artemia enriched with lipid emulsions containing highly unsaturated fatty acids on growth and survival of juvenile freshwater crayfish Astacus leptodactylus. Juvenile crayfish were fed artemia enriched with commercial emulsions (red pepper and olio ω3) and un-enriched artemia (control). The highest eicosapentaenoic acid (EPA) level was found in artemia enriched with olio ω3 (3.17 %) and the highest docosahexaenoic acid (DHA) level was found in artemia enriched with red pepper (3.56 %). The weight gain, specific growth, and survival rates of juvenile crayfish increased with increasing amount of EPA and DHA in dietary artemia respectively (0.04%, 2.32%). Finally, the juveniles fed with artemia enriched with olio ω3 and red pepper had a better weight gain, specific growth rate, and survival than those fed with un-enriched artemia (p<0.05).
    Keywords: Enrichment artemia, Astacus leptodactylus, Growth, Survival
  • E. Baghizadeh *, H. Khara Pages 99-111
    The purpose of this study was to determine changes in hematological and plasma indices of Common Carp Cyprinus carpio with regard to age, sex and hormonal treatment. Sixty fish were used to assess the age factor. Also, 20 fish including female and male were assigned to determine blood indices with regard to sex and hormonal treatment. The pituitary gland extract was used as hormone for males and females. Red blood cell (RBC), white blood cell (WBC), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), calcium, glucose, cholesterol, triglyceride, protein and phosphorus showed significant differences among ages. However, hematocrit (HCT), lymphocyte and neutrophil did not show significant differences. Statistical analysis revealed that males had higher values of RBC, Ht, Hb, MCV, MCH, lymphocyte, neutrophil and cholesterol compared to females. Some hematology and plasma indices influenced both sexes before and after hormonal treatment. These results provide useful information for monitoring changes in the health status of fish.
    Keywords: Hematology, Blood indices, Serum biochemistry, Cyprinus carpio
  • K.F. Konan *, O.E. Edia, K.Y. Bony, K.M. KouamE, G. GourEne Pages 112-129
    Fish assemblage was investigated during the study of longitudinal profile of the Ehania River Basin in south-eastern Côte d’Ivoire. This area is subjected to intense human activities with many plantations (palm tree, banana, pineapple, coffee, rubber and cocoa). Samples were collected, with gillnets of different mesh sizes, through 6 sampling surveys during dry and rainy seasons from February 2010 to December 2010 at 6 sampling sites. A total of 70 fish species belonging to 48 genera, 28 families and 10 orders were recorded. The temporal variation of diversity index is less marked than spatial variation. The upstream, with 35 species, was less rich in species than the medium area and downstream areas (respectively 46 and 68). The upstream and downstream areas gathered 35 species. Thirty three species were common to the upper and middle areas and 46 species appeared both in the lower courses and the middle area. The 21 species restricted to the lower part of the river are mainly estuarine/marine origin. The beta diversity value revealed low similarity between the lower and upper course of Ehania River. The lowest values of Shannon’s diversity index and equitability index were observed in the middle part of the River which characterized by high population density and intense agricultural activity with many plantations.
    Keywords: Fish assemblages, Diversity, Spatial gradients, Artisanal dams, Anthropogenic impact, Coastal river, West Africa
  • S. Tan, M. Bulut, S. Bilen * Pages 130-135
    In this study, fertilization, hatching and deformation rate of the eggs, and larvae obtained from hormone injected (HI) and non-injected broodstock (NHI), were determined. In the experiment, no differences were observed in the groups’ fertilization rates (p>0.05). Hatching rate was found higher in the HI group (p<0.05). During the experiment, malformations such as spinal fluid accumulation, saddleback, air-bladder deformation and general body deformations were observed in both groups. For the NHI group, saddleback rate was found 5.13±0.55 %, air-bladder deformation rate was found 1.43±0.13%, spinal fluid accumulation was found 2.33±1.33% and general body deformation rate was found 3.76±0.23 % (p<0.05). As a result, it was determined that the deformation rate increased with hormone injection (p<0.05).
    Keywords: Sea bass, Egg, Embryonic development, Expansion rates, Deformation
  • K. Al Hashmi *, M. Claereboudt, S. Piontkovski, A. Al Azri, S.M.N. Amin Pages 136-149
    The contribution of three different cell size classes of picoplankton: 0.74-2 μm, nanoplankton:2–20 μm and microplankton, >20 μm of the phytoplankton population and their relationship to environmental conditions were studied over two annual cycles at one station in Bandar Khyran Bay, Sea of Oman, from May 2006 to August 2008. Nanoplankton was the most important class contributing 54.4% to total Chl a (range 6-82%). Its seasonal highest concentrations was during the cold periods when temperature ranged from 28-29 °C in fall and near 24 C in winter when the supply of nutrients was sufficient to sustain their growth. Picoplankton had the second level of the contribution, comprising (23.5%, range 4-74 %) of the total Chl a. and their concentration was generally constant (0.04-.06 μg l–1) throughout the study period. The drop of picoplankton population coincided with an increase in the microplankton and nanoplankton populations indicating a high grazing pressure exerted on the picoplankton population. Microplankton size-class occupied the third level of the contribution comprising (22.2%, range 3-65 %). Their general concentration was below 0.1 μg l–1 and only dominant when temperatures were lowest and nitrate, nitrite, silicate and phosphate concentrations were the highest. The temporal variability observed was associated with changes in the nanaoplankton indicating that in some cases, it is the small fraction of phytoplankton that drives changes in abundances and productivity.
    Keywords: Phytoplankton, Chlorophyll a, Size, class, Picoplankton, Nanoplankton, Upwelling, Sea of Oman
  • G.Z. Pekmezci *, S. Umur Pages 150-157
    The presence of the anisakid nematode Hysterothylacium gadi aduncum (Rudolphi, 1802) is reported for the first time in cultured rainbow trout (Oncorhynchus mykiss Walbaum, 1792) as a new host in freshwater farms from Turkey. This marine parasitic nematode is thought to complete the life cycle in fresh water and rainbow trout could act as the definitive host for this parasite under fresh water culture conditions. Mortalities in the rainbow trout infected with H. gadi aduncum (Rudolphi, 1802), were seen after three to four months period of feeding program with marine fish offal (Sprattus sprattus, Engraulis encrasicolus) and pellet fish food. In the present study, the main cause of mortalities was detected as stomach obstruction formed by aggregation of the adult nematodes which developed from infective third stage larvae. Original measurements and figures are presented.
    Keywords: Hysterothylacium gadi aduncum, Rainbow trout, Fresh water environment, Turkey
  • N. Khosravi Bakhtiarvandi, A.M. Abedian, Kenari * Pages 158-175
    The ontogenesis and specific activities of pancreatic (trypsin, chymotrypsin, amylase and lipase) and intestinal enzymes (alkaline phosphatase, aminopeptidase N) were investigated in Kutum (Rutilus frisii Kutum) from the onset of exogenous feeding (3 day after hatching, DAH) to the juvenile stage at 50 DAH. Trypsin- and chymotrypsin-specific activity showed similar patterns and increased with larval development and age. After the first feeding, specific activity of amylase and lipase is increased and reach a peak at 10 DAH, followed by a sharp decrease until 25 DAH, after which it is increased again. Carbohydrate and lipid content changes in diet have led to fluctuations (increases or decreases) in amylase and lipase activities. Alkaline phosphatase and aminopeptidase N specific activity had similar patterns and showed increased trend with age. Sharp increases in activity for both enzymes from 7-10 DAH indicated maturation of the enterocytes and the achievement of adult-like mode of digestion. Our results suggest that Kutum is capable of digesting protein, lipid and carbohydrates at early stages of growth. However, due to low level of lipase-specific activity compared to other enzymes, it seems that Kutum larvae prefer diets containing higher protein levels than diets with higher lipid content. Therefore, for this species lipid component should remain at low level in formulated diets. In this study, specific activity of most digestive enzymes exhibited a sharp increase when co-feeding on rotifers and formulated diet started from 7-10 DAH. The increase in activities of pancreatic and intestinal enzymes in this period can be due to maturation of exocrine pancreas and brush border enterocytes, respectively and showed that this fish has ability to digest formulated diets.
    Keywords: Rutilus frisii Kutum, Larviculture, Pancreatic enzymes, Intestinal enzymes, Ontogeny
  • P. Pourashouri *, S. Yeganeh, B. Shabanpour Pages 176-187
    Salted Kutum roe was prepared by soaking in brine to a traditional procedure. Proximate composition (moisture, protein, lipid, pH, ash and salt content), total volatile basic nitrogen (TVB-N), fatty acid profiles and microbiological characteristics of raw and salted roe of Caspian white fish (Rutilus frisii kutum) were determined. The results indicated that protein and moisture contents were significantly higher in raw roe compared to salted one (28.81 and 61.07% to 23.99 and 51.57%, respectively). Significant differences in ash and salt contents were obtained among different treatments. TVB-N in all samples was less than 25mg/100g. The gas chromatography (GC) analysis showed that the major saturated fatty, monounsaturated fatty acids and poly unsaturated fatty acids were 16:0, 18:1n-9, and 22:6n-3, respectively. Aerobic plate count (APC) and Total Coliform Count (TC) in all samples were significantly higher (p<0.05) in raw roe (5.33 logCFU/g and 210 MPN/g) compared to salted roe (1.23 log CFU/g and 1.2 MPN/g). None of the samples contained Escherichia coli, Salmonella, Clostridium perfringens or yeast.
    Keywords: Rutilus frisii kutum, Roe, Salting, Microbial population
  • A. Oujifard, J. Seyfabadi *, A. Abedian Kenari, M. Rezaei Pages 188-200
    The effect of five isonitrogenous diets (36.6% protein), formulated by replacing 0, 25, 50, 75, and 100% of fish meal (FM) with rice protein concentrate (RPC), was investigated on the growth and tail-muscle fatty acid (FA) quality of juvenile Pacific white shrimp, Litopenaeus vannamei. The feeds were fed to shrimp (initial weight of 6.99 ± 0.08 g) five times daily to apparent satiation for 60 days. Final weight of shrimp fed with FM, 25 and 50% RPC was higher than that of shrimp fed with 75 and 100% RPC. Survival in shrimp was not significantly affected by dietary protein source and level (p>0.05). Regarding FAs, ∑n6 and PUFA increased significantly as the RPC levels increased, but the n-3/n-6 ratio, EPA+DHA, MUFA, SFA and ∑n3 were significantly declined (p<0.05). However, tail-muscle FA composition reflected the inclusion of plant protein. Lipid quality indices (AI and TI) showed significant variation, but were very favourable for the consumers’ health. The present study suggests that RPC can replace FM up to 50% in diets for L. vannamei with no significant effect on the growth, but a decreasing trend in quality of tail-muscle FAs was observed when the RPC level increased.
    Keywords: Fish meal, Fatty acids, Growth, Rice protein concentrate, Tail, muscle
  • G. Ruan, Q. Wan, F. Yao, Y. Yang *, J. Zhang, L. Huang Pages 201-216
    The compensatory growth, proximate composition and amino acid contents changes of young yellow catfish (Pelteobagrus fulvidraco R.) (1.63-1.69 g) had been investigated using a 45-day cyclic feed deprivation and re-feeding experiment. The control group (S0) was fed daily with live tubificid worms (Limnodrilus hoffmeisteri), while the S1/4, S1/2, and S1/1 groups cyclically experienced one-day of feed deprivation followed by four, two or one day(s) of feeding, respectively. Over- or full-compensatory growth was achieved in the cyclic deprivation/re-feeding groups through increased feeding rate (FR) and feed conversion efficiency (FCE). However, the fish behaved different courses of growth compensation, the compensatory growth responses of fish subjected to a weaker intensity of feed deprivation (i.e., S1/4) compared with more intense deprivation (i.e., S1/1) was achieved in these groups mainly by a gradual increases in FR or by maintaining a high FCE, respectively. The cyclic deprivation/re-feeding schedules did not affect the proximate composition of the fish body, however, the amino acid parameters were inversely related to the specific growth rate, the fish showing growth over-compensation contained significantly lower contents of total amino acids, essential and non-essential amino acids.
    Keywords: Amino acid, Compensatory growth, Over compensation, Feed conversion efficiency, Feeding rate, Proximate composition, Yellow catfish
  • M. Dehghani *, E. Kamrani, A. Salarpouri, E. Kamali Pages 217-231
    This is the first study of growth and age of Sardinella sindensis from coastal waters of Qeshm Island (Persian Gulf) based on the sectioned otolith reading method. In total, 128 fishes were collected randomly from purse seine commercial nets during March 2011 to February 2012. The annual formation of the growth rings were determined by counting the opaque and translucent zones occurrence at the outer margin of the otolith. The peak of opaque and translucent zones formation occurred in June and January, respectively. There was no significant differences between the sex ratio of males to females (p>0.05). The total length and body weight for both sexes ranged between (7.9-18.6 cm) and (3.98-55.69 g). In total, four age classes were determined, and the maximum age was recorded as 3.5 years. The most abundant individuals were counted in 1+ age class, while the least number of fishes belonged to the 3+ age class. The non-linear regression relationship between the length and age for combined sexes were fitted in Von Bertalanffy growth equation, and described as: TL= 20.8 (1-e-0.54(t+ 0.54)). There was a strong relationship between the body weight and total length of the fishes (p>0.05), indicating that the growth type of S. sindensis is isometric. From the results of this study we concluded that S. sindensis is a fast-growing species with a short-life span. In order to obtain more reliable results about the age and growth of this species, we suggest that different methods of age determination should be used, combined with the evaluation of the factors affecting its growth for the management of optimum exploitation of the resources of this fish.
    Keywords: Age, Growth, Otolith, Sardinella sindensis, Persian Gulf
  • S. Abdolnabi, M.Y. Ina, Salwany *, H.M. Daud, S.D. Mariana, Y.M. Abdelhadi Pages 232-245
    Aeromonas infections are becoming a major risk factor in commercial aquaculture and it has been reported that a wide variety of fish and shellfish species are susceptible to this infection. In this study, 3 isolates of Aeromonas hydrophila were isolated from giant freshwater prawn (Macrobrachium rosenbergii) cultured in Kuala Pilah Simbilan Nigri in East Malaysia. Conventional and rapid identification systems (API 20E strips) were used for preliminary identification based on the biochemical characters of the isolated bacteria. On the other hand, polymerase chain reaction (PCR) using the universal primer; 16S rRNA, was done as an accurate and confirmatory identification. The virulence of A. hydrophila was determined using a pathogenicity test via I/M injection. The results revealed that the isolated bacteria were identified as A. hydrophila that revealed a high degree of similarity (98%) to the NCBI or Genbank database. Based on pathogenicity test results, LD50 was determined as 1×106 CFU/50µl, while 1×107 CFU/50µl induced 100% mortality in the experimentally injected prawns. Histopathological changes were found in several organs including gill, hepatopancreas and heart. Those changes were mainly, melanisation, tissue erosion and necrosis, infiltration and hyperplasia of gill lamellae and mild or massive haemocyte reaction in the infected organs.
    Keywords: Aeromonas hydrophila, Giant freshwater prawn, Pathogenicity, Malaysia
  • W.N. Wan Hazma, Z. Muta Harah *, B. Japar Sidik, F.M.I. Natrah Pages 246-261
    The present study determined and compared contents of macro- (Nitrogen-N, Phosphorus-P, Potassium-K, Calcium-Ca, Magnesium-Mg) and micro- (Zinc-Zn, Iron-Fe, Manganese-Mn, Cupper-Cu) nutrients in four seagrass species; big-leaved (BL) Halophila ovalis (R. Br.) Hook. f., small-leaved (SL) H. ovalis (R. Br.) Ascherson, H. spinulosa (R. Br.) Aschers. in Neumayer and Halodule uninervis (Forssk.) Aschers from three locations; Merambong shoal, Seluyong shoal-1 and Seluyong shoal-2, Johore, Malaysia on March 2013. Dried seagrass samples were subjected to wet digestion method and concentration determined using a Perkin Elmer 5100 PC atomic absorption spectrophotometer. Macro and micro-nutrients varied with species and locations. Observed macro-nutrient contents were high for N (17320 mg kg-1) in big-leaved (BL) H. ovalis from Seluyong shoal-2, P (2921.33 mg kg-1) in big-leaved (BL) H. ovalis from Seluyong shoal-1, and for K (10942.67 mg kg-1) in H. uninervis from Merambong shoal and for Ca (10576 mg kg-1) in small-leaved (SL) H. ovalis from Merambong shoal. Mg (3534.67 mg kg-1) was comparatively higher in H. spinulosa from Merambong shoal. Micro-nutrients such as Zn ranged from 138.67 mg kg-1 to 212 mg kg-1 and Cu from 13.33 mg kg-1 to17.33 mg kg-1 with no discernible differences between species. Fe concentration was consistently higher in all species. Hierarchically macro and micro-nutrients contents did not show a consistent ordered pattern according to species and location. Based on biplots generated by Principle component analysis (PCA), there were clear separation of seagrass species based on the micro- and macro-nutrient contents with locations from Malaysia and other regions.
    Keywords: Halodule sp., Halophila sp., Macro, nutrient, Micro, nutrient, PCA, Malaysia
  • M. Taghavi Niya, M. Javaheri Baboli *, L. Roomiani, A. Pazira Pages 262-274
    In this study growth characteristics of 815 tuwini (Capoeta trutta) in Shour River were investigated during July 2010 through June 2011. The population was composed of 62.94% females and 32.02% males. Sex ratio was 1: 1.96, with significant differences observed at 1:1 (x2= 150.6; df= 1; p<0.05). The age distribution of this population ranged from <1 to 6 years. The distribution of length and weight was between 95 and 300 mm. The average length, except in <1 year olds, was statistically significant between sexes and average weight in all age groups was statistically significant between sexes (p<0.05). Weight-length relationship was determined as W=0.0115L2.9475 (R=0.91) in males and W=0.0096L3.0025 (R= 0.88) in females. Von-Bertalanffy growth equation was Lt= 24.5(1-e -0.333(t+2.54)) for males and Lt= 36.4 (1- e -0.129(t+4.02)) for females. Growth performance index was also estimated as Φ=2.301 in males and Φ=2.223 in females.
    Keywords: Capoeta trutta, Growth parameters, Shour river, Iran
  • S. Taheri *, A.A. Motallebi Moghanjoghi, T. Taheri, S. Faraji, P. Pourashouri Pages 275-288
    This study was aimed to investigate the effect of vacuum packing (VP) on the fatty acids profiles in cobia (Rachycentron canadum) fillets during an extended frozen storage period. Cobia fillets were treated under vacuum system then stored at -18°C for up to 6 months and compared to control conditions. As a result of a frozen storage period of 6 months, a marked content decrease was found in the fatty acid groups such as MUFA, PUFA and ω -3 PUFA, as well as in the ω -3/ ω-6 ratio. However, a preserving effect on such fatty acid parameters could be observed due to the VP treatment. Assessment of the polyene index (PI) indicated an increased lipid oxidation development as a result of the frozen storage time; however, this increase was partially inhibited by the vacuum packaging. Results indicate that vacuum packaging was a proper way to reduce lipid oxidation in Cobia fillets and extend their shelf life by omitting available oxygen. Thus the employment of VP alone or in combination with other protective strategies is recommended.
    Keywords: Fatty acids, Vacuum packaging, Frozen storage, Cobia Fish
  • P. Akbary *, A. Mirvaghefi, M. Akhlaghi, B. Majazi Amiri Pages 289-301
    The objective of this study was to contribute to investigate the efficacy of letrozole, a potent non-steroidal aromatase inhibitor, on serum sex steroid levels and oocyte growth in rainbow trout females. Serum steroid levels were measured using an indirect enzyme-linked immunosorbent assay (ELISA) before and 22 days after an initial injection with 1, 2.5 mg kg-1 and subsequent weekly injection with 2.5 mg kg-1letrozole. After the last blood collection, gonad tissues were removed and oocyte diameter and GSI were determined. In all groups treated with letrozole, serum 17β- esteradiol levels (E2) decreased significantly and inversely serum 17α-20ß dihydroxy-4 pregnen- 3- one (17α-20ß-P), testosterone(T) levels increased significantly from 6 to 96 h after injection (p<0.05). The lowest E2 levels, oocyte diameter and GSI were measured in the group treated weekly with 2.5 mg kg-1 letrozole (p<0.05). This study demonstrates that letrozole has the potential to interfere in the synthesis of endogenous estrogens from androgens and delay gonadal development.
    Keywords: Aromatase inhibitor, Sex steroid, GSI, Oncorhynchus mykiss