نشریه پژوهش های ماهی شناسی کاربردی
سال چهارم شماره 2 (تابستان 1395)

In this study, some biological characteristics of L. vorax were investigated in Shadegan wetland. Monthly sampling was done at five stations of Shadegan, including Doragh (mahshar), Rogabe, Khorosy, Salmane, and Atish. For this purpose, 456 specimens were caught using gill nets with 45 mm mesh from April 2012 to March 2013. Average and standard deviation length of female and male L. vorax were calculated per millimeters as 262 ± 31, 265 ± 29 and the average and standard weight in grams were measured, 192 ± 34, 194 ± 41, respectively. Length-Weight Relationship was calculated as negative alometric which was Y=0.00002L2.88 (R2=0.88). Furthermore, spawning period was determined in January to February. In addition, maturity length and maturity weight were calculated as 266 millimeters and 162 grams, respectively, and production rate per biomass annually was computed as P/B= 0.44. Fish growth indices were calculated to be L∞=498(mm), growth rate K=0.45 (yr-1) annually and to=-0.16 respectively. According to biological characteristics and with regard to American Fisheries Society (AFS) indices, this species is classified as mediate vulnerable group fishes.

This study was carried out to evaluate growth pattern of Cauacasian goby (K. caucasica) with 464 fish samples that obtained from February to May 2012 with beach line net. Sex ratio of male to female was 1:1.06 which does not show a significant difference between male and female in the population (X2 = 0.422, p > 0.05). Maximum total length and weight were recorded as 41.78 mm and 1.08 g for females, and 46.12 mm and 1.26 g for males. The weight - length relation for female was W= 0.0083 TL3.20 (r2 = 0.95) and the weight - length relation for male was W= 0.0079 TL3.20 (r2 = 0.97) and the total relation was W= 0.0082 TL3.19 (r2= 0.96). The results showed positive allometric growth (t-test, tmale= 4.94, tfemale = 4.22, tpopulation= 5.90, p

The present study aimed to determine monthly variations catch per unit effort (CPUE) of Benthosema pterotum (Myctophidea) in Iranians waters of the Oman Sea. In this survey, more than 665 cases of hauling net were analyzed from April 2011 to march 2012. CPUE in different seasons were calculated as 937±45, 1002±51, 828±51 and 640±43 kg/h in spring, summer, autumn and winter, respectively. In terms of trawling time, CPUE was calculated as 1108±60 in 2-3, 802±31 in 3-4 and 732±40 kg/h in>4 hours range. Furthermore, CPUE was calculated for different trawling depth and represented 922±33 for 250m depth layers. According to daytime in daybreak, CPUE was calculated as 779±37, 987±42 in the middle of the day and 805±48 kg/h in afternoon. Nonparametric Kolmogorov-Smirnov test showed normal distribution of CPUE data. The ANOVA test showed significance different between CPUE in different seasons, trawling time, trawling depth and daytime (P

This study was carried out to investigate the effects of different levels of thyme (Thymus vulgaris L.) essential oil on growth performance, hematological and serum parameters of Rainbow trout (Oncorhynchus mykiss). For this purpose, 4 treatments including 0 (control), 250, 500 and 750 mg thyme essential oil/kg diet were provided. 156 rainbow trout an average initial weight 69.38±0.44 gr were divided randomly in each treatment (with 3 replicates). At the end of 48 days, growth related parameters, hematological and biochemical parameters were measured. Results showed that growth related parameters including final weight, weight gain, weight gain percent, feed conversion ratio and specific growth rate had no significant differences among treatments (p>0.05). Dietary supplemented of Thyme essential oil had no significant influence on Hemoglobin, hematocrit and red blood cell compared to control (p>0.05). White blood cell showed significant difference compared to control, as the highest level of white blood cell was observed in 500 mg thyme essential oil/kg diet (p0.05). Serum lysozyme content showed significant difference between thyme treatments and control group and the highest level of lysozyme was obtained in treatment supplemented with 750 mg thyme essential oil/kg diet (p

In this study, in order to produce all female Rainbow trout, at first, sperm was harvested and then was irradiated by gamma radiation emitted from co60, b doses of 450, 600, 750, 900 and 1050 Gy. Then the different dozes of sperm was fertilized with normal eggs and thermal shock (28±0.5°C) was used for the induction of diploid. At the next stage for determination of hematological, biochemical and immunological indices, the experimental groups were underwent a six-month training period. At the end of the breeding period blood sampling was taken and then hematological parameters (containing red blood cells, white blood cells, hematocrit and hemoglobin, MCV, MCH and MCHC), biochemical indices (cholesterol, triglycerides, and albumin) and immunological parameters (containing total including protein, lysozyme and immunoglobulin) were measured in different units. For the completion of immune studies (MMCs and accumulation of lymphocytes), anterior sections of kidney tissue were separated and sampled in the experimental groups. The results showed that using gamma radiation for gynogenesis of rainbow trout does not have any significant effect on hematology and immunology indices in rainbow trout at different groups. This is while differentiation in hematological indices (containing red blood cells (RBC), white blood cells (WBC), hematocrit, hemoglobin, MCV, MCH and MCHC) showed significant difference between triploid group and other groups. The result showed that this method of genetic manipulation is comfortable for gynogenesis of this fish specieswithout affecting hematology and immunology indices.

In the present study, we investigated the effects of short –term exposure (96 h) and sub-lethal concentrations of diazinon on energetic (glucose, lactate) and osmotic parameters (chloride cells number, cortisol, total protein, blood plasma ions) of Persian sturgeon juveniles (Acipenser persicus) during salinity adaptation to seawater. 500 fish were distributed in twelve 100 L tanks at density of 40 fish per tank. The experimental treatments were: (1) 0.3 ppm (%10 LC50 96 h) diazinon, (2) 0.9 ppm (%30 LC50 96 h) diazinon (3) 1.5 ppm (%50 LC50 96 h) diazinon. Also, one diazinon-free group was considered as control. The experiment was conducted in two stages including: 96 h exposure in freshwater (FW) and 24 h exposure in brackish water (BW: 12 ppt salinity). After each stage, blood and gill tissue samples were taken. The results that diazinin can affect energetic and blood osmotic parameters of Persian sturgeon juveniles before and during the salinity adaptation period, especially in high concentrations (including 0.9 and 1.5 ppm). These effects includes: (a) 96 h exposure in FW: increase in cortisol, glucose, lactate and number of chloride cells (only in 0.3 ppm group) and decrease of ions. (b) 24 h exposure in BW: increase in cortisol, glucose and ions. In conclusion, our study showed that sub-lethal concentrations of diazinon (especially 0.9 and 1.5 ppm) reduce the potential of osmoregulation of the Persian sturgeon juveniles during salinity adaptation to seawater. These effects were: decreases in number of chloride cells, increases in stress indices (cortisol and glucose), changes in permeability of gills tissue and causing anaerobic condition which can affect the success of rebuilding the reserves of this precious species.

The present study was to evaluate the effects of dietary supplementation of lactobacillus acidophilus on growth performance and feed efficiency, digestive enzymes activity and some hematological parameters of Golden severum. In this study, 120 fish (Heros severus) with an average weight of 18.72±0.3 g distributed within experimental tanks, four treatments with 3 replications were arranged. Fish were fed 4 different levels of Lactobacillus acidophilus (0, 1.5×108, 3×108 and 6×108) for 60 days. At the end of the experiment, growth parameters, feed efficiency, digestive enzymes activity and hematological parameters were investigated. Results showed that lactobacillus significantly (p

Different studies on sturgeon sexing and gonad staging especially at early life history showed that some methods, such as biopsy, catheter and endoscopy, can cause severe physical damage to the fish in addition to high expenses. Also, the different genetic methods do not have suitable efficiency for sturgeon sexing. Methods like biometric and external morphology of fish urogenital opening are not sufficiently accurate for sexing. However, use of sex steroid hormone profiles and other blood biochemical indices and sonography techniques can lead to sex differentiation to some extent at high stages of maturity, but not at lower stages. Also, use of these methods is time consuming, expensive and need experts. Studies showed that different ways of sturgeon sexing and gonad staging can be used depending on aims, age and weight conditions. Results of this analytic study showed that laparoscopy and ultrasound methods, which are from less invasive and non-invasive methods respectively, are the best techniques for sturgeon in different sexing and gonad staging in various agesgroups, respectively.