فهرست مطالب

Iranian Journal of Fisheries Sciences
Volume:12 Issue: 4, oct 2013

  • تاریخ انتشار: 1393/11/20
  • تعداد عناوین: 21
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  • Author(S): F. Al Kiyumi, S. F. Mehanna *, L. Al Kharusi Pages 737-748
    The King soldier bream Argyrops spinifer at Arabian Sea (Omani waters) was assessed using Beverton and Holt yield per recruit model. A total of 5520 specimens were collected during five trawl surveys between September 2007 and August 2008. The maximum life span was 11 years for length range of 11.0 – 62.1 cm TL. The von Bertalanffy growth parameters were K = 0.22 year-1, L∞ = 65.51 cm, to = -0.75 year and W∞ = 5430g. The rates of total mortality Z, natural mortality M and fishing mortality F were 0.85, 0.26 and 0.59 year-1 respectively. The exploitation ratio E was 0.69 indicating the high level of exploitation. The estimated total length at 50% maturity was 31.8 cm. Yield per recruit analysis revealed over-fished stock conditions particularly because small fish are effectively unprotected by current minimum size regulations. Therefore measures such as closed seasons or changes in fishing patterns would be desirable to safeguard the spawning stock and recruits. Also, the commercial fishery of Arabian Sea, Oman should be subjected to a total allowable catch and a maximum size limit be implemented.
    Keywords: Arabian Sea, Argyrops spinifer, age validation, per, recruit analysis, fisheries regulations
  • Uuml, Mit Acar *, Ali TUrker, Musa Bulut, Ouml, Nder Yi, Ldi, Rim., Sevdan Yi, Lmaz, Osman Sabri KesbiC Pages 749-758
    This study was performed to determine the optimum level of soybean meal diets for two banded sea bream for growth performance, nutrient utilization, body composition and serum biochemistry. Two banded seabream were fed five experimental diets which were formulated replace fish meal by soybean meal at 0, 20, 30, 40 and 50%. Up to 40% of dietary fish meal was successfully replaced with no growth depression. Whole body composition of two banded seabream was not affected by soybean meal inclusion level. Total protein, triglyceride and total cholesterol of fish fed the SM50 diets were significantly lower compared to fish fed the soybean free diet. On the other hand, serum glucose level significantly increased as dietary soybean meal inclusion increased. Results showed that 40% fish meal can be replaced in diets for the two banded seabream by defatted soybean meal. Further studies to determine the inclusion level of soybean meal more than 40% with amino acid or enzyme supplementation are needed.
    Keywords: Diplodus vulgaris, serum biochemistry, body composition, growth performance, soybean meal
  • F. Amouei *, T. Valinassab, A. Haitov Pages 759-769
    The relationships between sagitta otolith morphology and fish size were examined for common carp in the Southern Caspian Sea; and also the aging of different length groups were determined. Statistical tests to examine correlation between left and right otoliths dimensions were carried out and no statistically significant difference between them was found. The biggest otolith had 0.032g weight belongs to an individual with BW= 428g and FL=36cm; and the smallest otolith had 0.014g for a fish with BW=220g and FL= 26cm. Regression model relations to each otolith morphometric parameter to fish length are provided. Also, the aging of this species was done by sectioning of sagitta otolith and a high significant correlations was found between fish age and morphometric parameters of both body weight and fork length and also otolith weight and length. The maximum age was determined 6+ years. The length-weight relationship was BW= 0.006 TL3.232 (r = 0.963). According to the morphometric relationships obtained, it was concluded that otolith length and weight are good indicators of fish body weight and fork length.
    Keywords: Sagitta otolith, Cyprinus carpio, age, Caspian Sea
  • Kemal, Ccedil, Elik * Pages 770-782
    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 minimu, 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.
    Keywords: Chlorophyll, a, eutrophic reservoir, nutrients, water transparency
  • R. Changizi *, H. Farahmand, M. Soltani, R. Asareh, Z. Ghiasvand Pages 783-791
    This study reports on the molecular identification of fish species from processed products which had a priori been classified as belonging to 5 important species in Iran for human consumption. DNA barcoding using direct sequencing of an approximately 650bp of mitochondrial Cytochrome oxidase subunit I (COI) gene revealed incorrect labeling of Narrow-barred Spanish mackerel samples. High occurrence of fraudulent fishery products, if left unchecked, can pose a negative impact on the economy. This investigation adds further concern on the trading of processed fish products in Iran from both health and conservation points of view.
    Keywords: Food traceability, Forensic genetics, DNA barcoding, Fish product
  • Qiqun Cheng *, Ningyu Huang Pages 792-801
    Esox lucius is an economically important freshwater species. Mitochondrial cytb, 12SrRNA, and 16SrRNA gene sequences were used in order to clarify the genetic variation and population structure in three E. Lucius populations, i.e., one Wild population (W) and two hatchery populations (Hatchery Population I-HPI and Hatchery Population II-HPII). A total of 55 individuals, with 19 from wild and 18 from each hatchery population, were sequenced. The results are as follows: 1) cytb. Eleven variable sites defined eight distinct haplotypes, with 1137 base pairs (bp) complete cytb sequences. The nucleotide diversity (π) values were W 0.009%, HPI 0.075% and HPII 0.068%, respectively. Genetic distances within and between populations were both between 0 and 0.1%. Analysis of molecular variance (AMOVA) analysis revealed that variation within populations accounts for 98.49% of total variation. 2) 12SrRNA. We obtained 380 bp consensus 12SrRNA sequence and found little variation among the 55 sequences. 3) 16SrRNA. Twelve variable sites defined seven haplotypes, with 519 bp consensus 16SrRNA sequence. The π values were W 0.041%, HPI 0.310% and HPII 0.021%, respectively. Genetic distances were between 0 and 0.3% within populations and from 0 to 0.2% between populations. AMOVA disclosed that variation within populations accounts for 91.79% of total variation. Variation within populations is the main source of total variation. The results suggest that low genetic variation can be found in both wild and hatchery populations of E. lucius, and the effect of genetic drift and adaptation to culture conditions gradually emerged under only two generations’ artificial cultivation.
    Keywords: Esox lucius, mitochondrial DNA, genetic diversity, genetic variability, hatchery
  • S.Y. El-Zaeem *, G.M. Salam Pages 802-812
    This study was conducted to produce a high percentage of genetically male tilapia through interspecific hybridization between Nile tilapia, Oreochromis niloticus and Blue tilapia, O. aureus and evaluate sex ratio, productive performance and heterosis of the progeny produced. The results revealed that sex ratios of the progenies of (♀ O. aureus x ♂ O. niloticus) and (♀ O. niloticus x ♂ O. aureus) were 4.28: 1.00 and 3.59: 1.00 and differ (P<0.05; df =1) significantly from the expected sex ratios of 3.00: 1.00 and 1.00: 0.00, respectively. In addition, the productive performance traits of (♀ O. aureus x ♂ O. niloticus) had significant (P≤0.05) superiority in most of these traits. Moreover, although both hybrids displayed a positive or best heterosis for daily gain, SGR%/day, FCR and PER, the hybrid of (♀ O. aureus x ♂ O. niloticus) showed the highest or best heterosis.
    Keywords: Genetically male, interspecific hybridization, Nile tilapia, Blue tilapia, productive performance, heterosis
  • B. Ghaednia *, M. Bayat, I. Sohrabi Haghdoost, A.A. Motallebi, A. Sepahdari Pages 813-826
    Mycotoxins contamination of feedstuff for aquatic animals is common in regions with humid tropical conditions. In this study Indian white shrimp, Fenneropenaeus indicus, (11.79 ± 1.76 g) were fed with diets containing 0, 20, 50, 100, 200, 400, 800 and 1600 ppb levels of aflatoxin B1 (AFLB1) for 8 weeks. Final weight, aflatoxin B1 residue (2-week intervals), Total Hemocyte Count (THC), Total Plasma Protein (TPP), Phagocytic Activity (PA), Survival rate (4-week intervals) were determined. Histopathological alterations in hepatopancreas, midgut and muscle tissues were studied at the end of 4 and 8 weeks. Shrimps fed with the 1600, 800 and 400 ppb concentrations of AFLB1 exhibited slow growth, and more reddish discoloration disseminated over the body at 4th week. Growth parameters, survival rate and health indices (THC, TPP) of F. indicus, are affected by the different doses of AFLB1 in diets. At the end of 8th week, doses of AFLB1 in the diets showed negative correlation to final weight, survival rate, THC and TPP (r = - 0.312, -0.603, -0.237 and - 0.649 at P<0.001, respectively). Moreover, significant histopathological alterations in the hepatopancreas, midgut and muscle tissues of exposed shrimps to different levels of AFLB1 were observed and these alterations are obviously indicated by changes in the health indexes (THC and TPP).
    Keywords: Aflatoxin B1, Fenneropenaeus indicus, growth performance, health indices, histopathological alteration
  • S.H. Hosseini *, S. Alinezhad, I. Mobedi, A. Halajian, E. Karimi, M.B. Ahoo, M. Yasemi Pages 827-835
    The Persian Gulf is of great economical, environmental and political importance, and includes around 205 species of fishes that only some of them have been studied parasitologically. From the order Pleuronectiformes (ray-finned fishes), Psettodes erumei (Psettodidae), Pseudorhombus elevatus (Bothidae) and Brachirus orientalis (Soleidae) were selected for the survey. One hundred and forty eight fishes including 97 P. erumei, 43 P. elevatus and 8 B. orientalis were provided from two different regions of Iranian waters of the Persian Gulf and Oman Sea. From P. erumei, 4 species of nematodes, one cestode and one acanthocephal species are reported including: Philometra sp., Contracaecum sp., Pseudoterranova sp., Raphidascaris sp., Dasyrhynchus sp. (Trypanorhyncha) larvae and Serrasentis sagittifer. This is the first report of S. sagittifer in P. erumei from the Persian Gulf. P. elevatus had fewer species of parasites including one nematode, Contracaecum, one copepod, Heterochondria pillai and one digenea metacercaria Stephanostomum sp. Brachirus orientalis harbored one copepod and two digenea species, Allocreadium sp. and Lepocreadioides zebrini. Our research provides evidences that Indian spiny turbots have larger diversity of parasites than the deep flounders.
    Keywords: Pleuronectiformes, Fish, Parasites, Persian Gulf
  • H. Hosseinzadeh Sahafi *, S. Masaeli, M. Alizadeh, H. Negarestan, T. Naji Pages 836-842
    In this research, growth rate, blood parameters and proximate composition of rainbow trout (Oncorhynchus mykiss) cultured in brackish and freshwater were evaluated. Two treatments (brackish and freshwater) in 3 replications were investigated. Six 1.5 m³ fiberglass tanks were used for this experiment, containing 180 rainbow trout specimens with average weight of 47.2±0.1g. Feeding rate in treatments was about 3% of body weight based on water temperature and fish biomass. Total length and weight of fish were measured in 15 days intervals. After 135 days of culture period, some fish samples were transferred to the Lab. Blood were directly collected from the heart. Muscle composition was analyzed for proximate composition. The results showed that the body weight of samples in brackish water was increased significantly after 45 days of culture period. Blood factors including WBC, RBC, Hb, Hct, MCV, MCH, MCHC, lymphocyte, thrombocyte and concentration of K+ ions in fish cultured in brackish water showed a significant increase (P<0.05). Muscle composition analysis showed a significant increasing (p<0.05) in fat and dry matter in freshwater treatment, while moisture was significantly higher in brackish water (P<0.01)
    Keywords: Rainbow trout, brackish water, freshwater, blood factors, proximate composition, growth
  • Zhou Jing *, Cai Junpeng Pages 843-854
    This study was 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.
    Keywords: Haliotis diversicolor supertexta, massive death, challenge test, Oceanomonas doudoroffii, 16S rDNA sequencing
  • F. Kaymaram *, M. Darvishi, S. Behzadi, S. Ghasemi Pages 855-863
    Length frequency data of the longtail tuna, Thunnus tonggol collected from October 2006 to September 2007 were analyzed for evaluation of the stock parameters. T. tonggol is mainly caught by gillnet method. Yearly tuna and tuna-like catches in Iran are of the order of 174,234 mt, close to 46% of which are longtail tuna. The VBG parameters for longtail tuna were: L∞ =133.72cm; K=0.35 year−1.The length –weight relationship was estimated as: W=0.00002 L 2.83.The instantaneous rates of total mortality (Z) was estimated by using the Powell-Wetherall plot as 1.82 year−1. The instantaneous rate of natural mortality was obtained by Pauly equation (M=0.44 year−1) and the instantaneous rate of fishing mortality (F) estimated from Z-M=1.38year−1.
    Keywords: Growth, mortality parameters, Thunnus tonggol, Persian Gulf, Oman Sea
  • M.S.K. Khan *, M.A.M. Siddique, H. Zamal Pages 864-872
    The nutritional suitability and cost effectiveness of rice polish and mustard oil cake as protein sources in the diet of Nile tilapia (Oreochromis niloticus) were studied. This study introduced rice polish as a plant protein source for Nile tilapia and three diets were formulated using rice polish (0, 10 and 20%) and mustard oil cake (10.0, 17.6 and 22.0%) for a feeding trail of eight weeks to observe the growth performance and feed utilization. The result was indicated that growth performance tended to decrease with increase in inclusion level of rice polish and mustard oil cake. The control diet (FM35) recorded the highest body weight gain (BWG) (363.79±59.32%) and the least (330.24±32.32%) was in diet FM25. Specific growth rate (SGR) was followed the same trend and no significant differences of SGR was observed among the diets (P>0.05). Feed intake (FI) of different diets was ranged between 30.33 g and 35.08 g per fish at the end of this experiment. Feed intake was also declined with the increase in inclusion level of rice polish, though the feed conversion ratio (FCR) and protein efficiency ratio (PER) were not significantly different (P>0.05) among the diets. The results of this study revealed that partial replacement of fish meal by rice polish and mustard oil cake would be cost effective without any significant change in growth performance.
    Keywords: Rice polish, mustard oil cake, plant protein sources, O. niloticus, growth performance
  • M. Mirbakhsh *, A. Akhavansepahy, M. Afsharnasab, A. Khanafari, M.R. Razavi Pages 873-886
    Isolation of autochthonous bacteria from marine sources as a potential probiont in biocontroling against pathogenic Vibrio species in the shrimp culture industry was the aim of current research. A total of 198 bacterial strains were isolated from pond water, sediment, hepatopancreas and gut samples of shrimps after culturing the samples on Tryptic Soy Agar and incubated at 30 °C for 24-48 h. The isolates were tested for their antagonistic activity in contact with Vibrio harveyi. Two strains (IS02 and IS03) that isolated from the gut and pond sediment were showed antagonistic against V. harveyi. According to 16S ribosomal DNA gene sequence analysis, the strain IS02 was identified as Bacillus subtilis and IS03 as B.vallismortis. Further, the two bacterial species, B. subtilis and B. vallismortis were challenged separately for probiotic activity in the post larvae of Litopenaeusvannamei against pathogenic V. harveyi. The present study identified B.subtilis IS02 and B.vallismortis IS03 had biocontrol activity against V. harveyiin vitro and in vivo and they increase growth performance of L.vannamei in post larvae stage.
    Keywords: Probiotic, Litopenaeusvannamei, Indiginous bacteria, Vibrio harveyi
  • A. Naeemi *, S. Jamili, N. Shabanipour, A. Mashinchian, S. Shariati Feizabadi Pages 887-897
    The histopathological effects of Linear Alkylbenzene Sulfonate on the gill, liver and kidney tissues of the Caspian kutum, Rutilus frisii kutum were studied. The fish were exposed to three sublethal concentrations of anionic detergent, Linear Alkylbenzene Sulfonate (LAS) for short term intervals (192 h). Gill, liver and kidney samples were collected after 192 h of exposure to LAS and lesions were analyzed by light microscopy. The histological changes to gills were edema, fusion of lamellae and lamellar aneurism. Some alterations like reduction of the interstitial haematopoietic tissue, tubular shrinkage, degeneration in the epithelial cells of renal tubule and necrosis were observed in the kidney. In the liver tissue, hepatocyte degeneration, congestion and dilation of sinusoid and vacuolar degeneration were seen. It seems that sublethal concentration of LAS may affect sever changes to gill, kidney and liver of R. frisii kutum specimens that leads to malfunction of these organs which cause damage to health of the fish.
    Keywords: Rutilus frisii kutum, Linear Alkylbenzene Sulfonate (LAS), histopathology, gill, liver, kidney
  • E. Sadripour Mortazavi *, N. Mahdavi Shahri Pages 898-907
    This study investigated the effects of increasing mercury (Hg) concentration on early developmental stages of sea urchin, Echinomethra mathaei, as a bioindicator. The toxicity test was carried out after the gamete released induction and fertilization in six concentrations of mercury within the range of 4, 8, 16, 32, 64 and 128 µg/L. Embryos samples were incubated for 30 h in control and test solutions. After incubation, the percentage of developed 4-arm pluteus larvae was recorded in each group and embryonic abnormalities were studied by a microscope. Results of this study indicate that exposure of embryos to increasing mercury concentrations lead to abnormalities such as changes to shape and size of pluteus larval arms and also arrested development in early embryonic stages. Furthermore, embryos were analyzed to determine mercury absorption by cold vapour atomic absorption spectrometry method (AAS). The median effective concentration (EC50) value calculated for mercury was 17/42 µg/L.
    Keywords: Mercury, Sea urchin, Toxicity test, Echinometra mathaei, Persian Gulf
  • M. Sharif Rohani *, M. Masoumzadeh, M. Haghighi, J. Jalilpoor, M. Pourdehghani, A. Shenavar Masouleh, M. Alizadeh, S. Bazari Moghaddam Pages 907-915
    In order to does this study, 150 Persian sturgeons having 75g mean weight transferred to 500 liter tanks. After dividing the fishes into two groups (experimental and control), the fingerlings fed by concentrate food that contained different levels of Zataria multiflora essential oil (15, 25, 50, 100 g/kg) for 8 weeks. Finally, sampling carried out on blood and serum of fishes. After preparing the samples based on standard methods, hematology and serology studies, performed. The results showed significant difference in mean of monocytes between experimental and control groups (P<0.05). In treatment 25g/kg, monocyte count was more than other treatments. But there were no significant differences in mean and standard deviation of other white blood cells. The results of serologic studies showed no significant differences in serum indices (C3, C4 and total protein) (P>0.05), but there is significant difference in mean and standard deviation of albumin. So that, the average in treatments 15 and 25g/kg and control group was more than treatments 50 and 100g/kg of Zataria multiflora essential oil.
    Keywords: Zataria multiflora, essential oil, hematology, serology, Persian Sturgeon
  • M. Shirinabadi *, A. Matinfar, A. Kamali, H. Hosseinzadeh Pages 916-927
    In this study, the effects of different light regimes on the reproductive activity of a typical Indo- Pacific coral reef rabbitfish, Siganus sutor, were evaluated. Forty- five adult fish were exposed to nine different photoperiod (8L: 16D, 12L: 12D, 16L: 8D) and light intensity (1000, 2000, 3000 lux) combinations with three replicates and five other fishes reared under indoor light condition (Control). Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) were calculated after 60 days and compared among different experimental regimes in males and females. In the control group, GSI and HSI mean values were 4.67 and 3.24%, respectively, for females and 10.05 and 2.10%, respectively, for males, and these fish showed differences in comparison with the exposed fish. Females kept under 1000 and 2000 lux light intensities had a higher GSI mean value (9.26 and 10.39%, respectively) and also lower average HSI (2.10 and 2.31%, respectively) in 16L: 8D treatment. A similar result was also obtained for males, whereas the 3000 lux light intensity, 8L: 16D day length combination led to more gonadal development (GSIs of 16.41% in females and 12.03% in males). A comparison of results among different photoperiods also confirmed that maturation was induced better in fish maintained under 16L: 8D in both sexes. This investigation revealed the visible role of both photoperiod and light intensity on inducing maturity in the whitespotted rabbitfish, S. sutor. Thus, rearing of adults exposed to an artificial light regime, including 16L: 8D and 2000 lux light intensity, promotes more gonadal development than that occurring in the wild.
    Keywords: Photoperiod, Light intensity, GSI, HSI, rabbitfish, Siganus sutor, Persian Gulf
  • Z. S. Talas *, M. F. Gulhan Pages 928-938
    Bee-collected pollen (bee pollen) is reported as a health food with a vast range of nutritional and therapeutic effects. Biochemical and hematological parameters in blood of rainbow trout treated to various concentrations of pollen (0.5, 2.5, 5, 10, 20 and 30 ppm) for 96 h were determined. The levels of total protein, creatinine, chloride and sodium in fish which exposed to different concentrations of pollen were not changed (P>0.05) as compared with the control group. In this study, the highest total antioxidant capacity of pollen were determined at 10 ppm concentration and paraoxonase activity was not observed in the fish serum. It is concluded that concentration-dependent effects of pollen on blood of fish can be favorable in disease prevention.
    Keywords: Pollen, Biochemical parameters, Fish, Hematological parameters, Paraoxanase, Total Antioxidant Status
  • A. R. Vajhi *, O. Zehtabvar, M. Masoudifard, M. Moghim Pages 939-946
    Sturgeon is one of the most important species of the Caspian Sea aquatics. Unfortunately, this species faces the threat of extinction today. This makes specific studies on any type of sturgeons more important than before. Studies like histological studies, radiology, and sonography, all require a complete understanding of the anatomy of this fish. Since pilot studies showed some misconceptions in description of the sturgeon digestive system, this study was conducted to evaluate more precise anatomical structure of the digestive system of Acipenser persicus as the most important sturgeon species of Iran. A total of 40 adult Acipenser persicus were used in this experiment. They were autopsied primary to the study. All parts of the digestive system from buccal cavity toward rectum and anal orifice were evaluated. The anatomical structure and relations of the different parts of the digestive system including oral cavity, pharynx, esophagus, glandular stomach, muscular stomach, pyloric process, small intestine, spiral intestine, rectum, liver and pancreas were described. The digestive tube is relatively short. The stomach has two parts. The first part, or the proventricle, is U-shaped. The second part or gizzard has thick muscles and is almost surrounded with liver lobes. Pyloric caecum is located on the left side bottom of the gizzard as a sponge like structure. The intestines are made of 3 parts: the small intestine, the spiral colon, and the rectum. The small intestine has two flexures that separate it to three parts named the descending, ascending, and the end part, respectively. The spiral colon is the longest part of the digestive tube. This part has mucosal spiral septum on the inner surface. The rectum is short and located in the middle of the abdominal cavity. However, in the present study the opening was shown to be located in the muscular stomach and the intestine junction, just close to the gall bladder duct opening.
    Keywords: Digestive system, Anatomy, Acipenser persicus
  • M. Yildiz, M. Kayim *, S. Akin Pages 947-961
    In this study, anesthetic effects of five different concentrations of 2-phenoxyethanol (0.2, 0.3, 0.4, 0.5 and 0.6 ml/L) and clove oil (0.50, 0.75, 1.00, 1.25 and 1.50 ml/L) on rainbow trout (Oncorhynchus mykiss) were studied at temperatures 7, 13 and 18ºC. For this purpose, 900 fish (39.08 ± 1.13 g and 15.48 ± 0.21 cm) were used in the experiment. Induction time of 2-phenoxyethanol and clove oil varied between 1.05 and 3.36 min at all concentrations, except for 0.2 ml/L (for 2-phenoxyethanol only) and at every temperature application. Full recovery time occurred between 2.44 and 7.14 min for 2-phenoxyethanol and 3.23 – 6.11 min for clove oil. It was found that full recovery times significantly increased with increase in 2-phenoxyethanol concentrations (r2=0.81). The same increasing trend was observed in clove oil, but the increase was not strong compared to 2-phenoxyethanol (r2=0.21). On the other hand, full induction times of 2-Phenoxyethanol and clove oil significantly declined with the increase in concentrations (r2=0.74; r2=0.84 for 2-phenoxyethanol and clove oil, respectively). Based on the ideal induction (less than 3 min) and recovery (less than 5 min) time criteria, it can be suggested that the most appropriate concentrations for rainbow trout were 0.3, 0.4 and 0.5 ml/L for 2-phenoxyethanol and 0.50, 0.75 and 1.00 ml/L for clove oil.
    Keywords: Anesthetic, Clove oil, Oncorhynchus mykiss, Temperature, 2 phenoxyethanol