Effect of male age in Caspian brown trout, Salmo trutta broodstock on reproductive performance

In this study, three different age groups of male broodstocks (4, 5 and 6 years respectively) were used to fertilize eggs obtained from nine females. The results showed that 6 year old males had maximum body weight (1766 g), total length (56.3 cm) and sperm volume (31.83 ml). Results did not show significant difference in spermatocrit and spermatozoa concentration among age groups (p>0.05). Our study showed maximum fertilization rate (98.5 %), survival rate until eyes pigmentation (91.17 %), hatching rate (94.5 %) and survival rate until absorption of yolk sack (97.16 %) for 4 years treatment group. Such positive relationships were detected between sperm production characteristics (spermatozoa concentration, spermatocrit and sperm volume) and fertilization parameters. Based on our results, it can be concluded that 4 year old males have high efficiency leading to fertilization success

Sex steroid levels, reproductive indices and histological examination of gonads in adult male and female Caspian shemaya, Alburnus chalcoides

Reproductive status of Alburnus chalcoides adults from Anzali Wetland was investigated by histological examination of gonads, assessment of sex steroids (i.e. Progesterone (P), Estradiol-17ß (E2), Testosterone (T)) and reproductive indices (i.e. absolute fecundity, oocyte diameter, hepatosomatic index (%HSI) and gonadosomatic index (%GSI)). Totally, 42 females and 16 males were captured during March to May 2014 by gill net and divided into two age groups including 2 year olds and 3 year olds. In each age group, fish were classified into two groups depending on maturation stage i.e. matured and maturing fish. According to the results obtained, in each age group, there were no significant differences between matured and maturing males and females in terms of absolute fecundity (p>0.05). In each age group, oocyte diameter was higher in matured fish than in maturing individuals (p<0.05). In 2 year old males and In 3 year old females, higher HIS values were recorded in maturing fish compared to matured fish. In females, the plasma levels of E2, T as well as P were significantly higher and lower in maturing fish and matured individual, respectively. In males, only plasma T was higher in matured fish compared to maturing fish and other assayed steroids did not show significant differences. Also, the histological examination of gonads from 10 males and females showed that all fish were in the final maturation stages

Interaction of dietary Pediococcus acidilactici and folic acid on growth performance, haematological parameters and non-specific immune response of finger barbel, Acipenser nudiventris

This study was conducted to investigate the effects of dietary Pediococcus acidilactici and folic acid (FA) and their combinations on growth performance, haematological parameters and non-specific immune response of Acipenser nudiventris. 210 individuals (initial body weight: 12.84± 1.53g) were fed seven practical diets: the basal diet as the control diet was supplemented with two levels of P. acidilactici (2 and 3 g per kg diet), FA (2 and 4 mg per kg diet) and their combinations. The results showed that the group fed a combined diet of P. acidilactici and FA (4 mg FA+3 g P. acidilactici per kg diet) showed significant increase in body weight increase (BWI), specific growth rate (SGR), feed conversion ratio (FCR) and condition factor (CF). However, experimental diets had no significant effects on survival rate. Both haematological indices and leucocyte counts were significantly (p<0.05) influenced by dietary P. acidilactici and FA and their combinations. In the group fed 4 mg FA+3 g P. acidilactici, lysozyme activity and total immunoglobulin (Ig) levels significantly increased compared to those fed other diets (p<0.05). Moreover, the fish fed diets supplemented with 2 mg FA+ 3 g P. acidilactici per kg diet had considerably higher immunoglobulin (IgM) level (p<0.05). Under the experimental conditions, dietary P. acidilactici and FA had a synergistic effect on enhancing growth performance and immunity of A. nudiventris

The effect of vitamin C and E supplement in diet on the growth and immunological parameters of Caspian salmon (Salmo trutta caspius)

This study was performed in order to investigate the importance of vitamin C and E in diet. In this study the effect of vitamin C and E supplement in diet on hematological and growth parameters of Caspian salmon have been investigated. Samples were Caspian Salmon juveniles (35±0.24 gr) which feed by extrude growing diet (EX-TG2) by different concentrations of vitamin C and Esimultaneusly. Different treatments (1 to 10) used in this study consisted of 100, 200, 300 mg/kg vitamin C by 20, 30, 40 g/kg vitamin E regularly. Last treatment feed with control diet. All fishes daily feed in 3% of their body weight 3 times a day. To investigate the interaction between vitamin C and E, this supplements used simultaneously in diet. Results shown that there is difference between treatments in growth parameters. Also results shown that treatments with higher vitamin C concentration had ore effect on growth and survival parameters significantly (p<0.05). Furthermore control treatment samples had lower growth and survival and higher FCR compare with treatment groups (p<0.05). Also there was significant difference between treatment groups in hematological parameters. WBC and Nutrophil and hematochrit were significantly higher in treatments with higher vitamin C concentrations (p<0.05). But there was not any differences in Lymphocytes and monosites between treatment groups. Total Immunoglobulin and lysosime was higher treatments with higher vitamin C and E (p<0.05). The conclusion of this study have shown that the best dos of vitamin C and E in diet was 300 and 30 mg/kg regularly. Also the results shown that there was an interaction between this two supplements in Caspian Salmon diet

Morphological variation of golden mullet, Liza aurata, of southern coasts of the Caspian Sea

Morphological features of Golden mullet (Liza aurata) population in the southern coasts of the Caspian Sea were studied. A total of 228 fish specimens were collected from Bandar Anzali, Kiashahr, Babolsar and Bandar Turkman in Iranian waters. A combination of Truss network, traditional system and few meristic counts were simultaneously applied to the sample set. Statistically high significant morphometric differences were observed between the four L. aurata stocks. Univariate analysis of variance (ANOVA) revealed significant differences between the means of samples for 10 out of 25 standardized morphometric measurements of truss system, 3 out of 7 measurements of traditional morphometric system and also the number of second dorsal fin spines, soft rays of second dorsal fin, total number of pectoral fin rays, soft rays of anal fin, number of squmosum scales and pyloric caeca among meristic counts. Discriminant analysis correctly classified 76% and 70.3% of individuals into their original samples for morphometric features and meristic counts, respectively. Plotting discriminant functions revealed differentiation of the four stocks based on morphometric measurements. The Bandar Anzali stock was isolated from the others, and the Baholsar stock was found to be located between Kiashahr and Bandar Turkman stocks. The pattern of morphological discreetness suggests a direct relationship between the extent of morphological divergence and geographical separation

Effect of dietary estradiol-17β on growth performance, body composition and blood indices in Stellate sturgeon, Acipenser stellatus

This study was investigated the effects of dietary estradiol-17β (E2) on growth, body composition and blood indices in Acipenser stellatus. Fish (40.9 ± 1.1 g average initial weight; n = 60 per group) were fed with three different diets containing 0 (control), 25 and 50 mg kg-1 dietary estradiol contents to apparent satiation for seven months. The results suggested that growth rate were decreased as the E2 level was increased. No significant difference was observed in condition factor among dietary treatments. The highest survival rate was observed in fish fed control diet, but was not significantly different among the treatments (P>0.05). Body composition did not show significant changes among dietary treatments. Number of white blood cells and red blood cells, hemoglobin and hematocrit values were significantly decreased as the E2 levels were raised (P<0.05). Plasma biochemical parameters including glucose, total protein, cholesterol, triglyceride, calcium, and phosphorus levels were dose dependent with the lowest levels in control with the highest levels in fish treated with 50 mg E2. The results of the present study revealed growth suppression of dietary E2 and changes of blood indices with providing some basic information on the effect of estrogen hormone on physiology of sturgeon

Effective factors on adoption technology among trout fish farms in Guilan Province

The main purpose of this study was to investigate effective factors on adopting technologies among trout fish farmers in Guilan province by Unified Theory of Acceptance and Use of Technology (UTAUT). Statistical population of this research contained of all managers of trout fish farms of Guilan province (N=170) that base on limitation of structural equation modelling in determining sample size, 97 of them were chosen as a sample. Study tool was contained Vankatesh and et al. information technology questionnaire in six items. To obtain validity of questionnaire; content, face, convergent and discriminant validity were used. As well, to obtain reliability of questionnaire; principal component analysis, Cronbachs alpha, Dillon-Goldstein’s ʃ and reagent stability were used. To accomplish analysis of data, SPSSV19 and SmartPLSV2 software were used in descriptive and inferential statistics. For testing hypothesis, structural equation model (SEM) and partial least squares (PLS) that focus on reagent variance were used. The results showed that there was significant relationship between performance expectancy and behavioral intention. Also there was significant relationship between intention to use and use behavior of aquaculture technologies. Model explains 28.8 percent of behavioral intention variance and 7.9 percent of use behavior of aquaculture technologies variance among trout fish farmers. To increase willingness to accept the technology among trout fish farms in Guilan province, it is suggested that extension-education courses for raising knowledge and awareness of aquaculture technology to be held by organizations. Providing financial resources and adequate knowledge will enable trout fish farms to equip with the aquaculture technologies

Effects of LHRH-A2 and chlorpromazine (dopamine antagonists) on inducing spawning in Caspian Kutum, Rutilus frisii kutum, from the southwest of the Caspian Sea

Caspian kutum, Rutilus frisii kutum, is one of the most commercially important fish species in the Caspian Sea, but there are few reports about the endocrinology of induced spawning in this fish. In the present study, 54 individuals of female broodstocks of Kutum were studied for quantity and quality of propagation index, during March and April 2007. Hormone treatments include: LHRH-A2 (1 µg kg-1bw;chlorpromazine (2.5 mg kg-1bw); LHRH-A2 + chlorpromazine (1µg kg-1bw+2.5 mg kg-1bw); CPE as a positive control (1 mg kg-1bw); Physiological saline as a negative control; and normal brood stocks without injection. For histological examinations, ovarian samples of non-ovulated females were fixed in bouin's fluid. The routine procedures of preparation of tissues were followed and the paraffin blocks were cut at 5-7 microns, stained with H&E and studied under light microscope. The results showed that the highest percentage of ovulated females belonged to group 1 without significant difference with positive control.There was a significant difference between ovulated females in the LHRH-A2, chlorpromazine and LHRH-A2 + chlorpromazine treatments (P0.05). Chlorpromazine could not be a potent dopamine antagonist and the microscopic observations of ovary in non- ovulated brood stocks showed that the oocytes in these treatments were in the final phase of IV stage

An investigation on digestive parasites of fishes in Boojagh Wetland, north Iran

Digestive parasites of commercial fish species in the Boojagh wetland were studied in 2002. The fish species included Esox lucius, Cyprinus carpio, Blicca bjoerkna, Tinca tinca, Carassius auratus, Rutilus frisii kutum, Rutilus rutilus and Scardinius erythrophtalmus. Species C. auratus, R. frisii kutum and B. bjoerkna were found free of digestive parasites. The other five species were carrying one of the three digestive parasites Raphidascaris aces, Caryophyllaeus fimbericeps and Asymphylodora tincae. R.acus parasite was isolated from E. lucius and E. erythrophtalmus infecting the species with a mean intensity of 1.1± 11.15 and 1.8±0.83, a prevalence of 15.4% and 20.2% and a mean abundance of 1.69 and 0.38 respectively. C. carpio and R. rutilus were only infected with C. fimbericeps parasite with a mean intensity of 30.30±46.33 and 5±0, a prevalence of 46.5% and 2.78%, and a mean abundance of 15.48 and 0.14 respectively. The parasite A. tincae was observed only in T. tinca infesting the fish with a mean intensity of 20±0, a prevalence of 25% and mean abundance of 5. Infection of Esox lucius with the parasite A. tincae had been reported from other sites, but this is the first record of Scardinius erythrophtalmus being infected with the parasite. This is also the case for infection of C. carpio with the parasite Caryophyllaeus fimbericeps which was reported before, but found infesting R. rutilus in the Boojagh wetland for the first time

Parasites of some bonyfish species from the Boojagh wetland in the southwest shores of the Caspian Sea

The Boojagh international wetland with a surface area of 80 hectares and 25 fish species is located in the southwest shores of the Caspian Sea (Guilan province, Iran), but there is no report about fish parasites in this wetland. In the present study, a total of 553 individuals of 8 fish species including Cyprinus carpio (n=71), Abramis bjoerkna (n=153), Carassius auratus gibelio (n=89), Esox lucius (n=39), Rutilus rutilus caspius (n=36), Rutilus frisii kutum (n=81), Scardinius erythrophthalmus (n=119) and Tinca tinca (n=4), were collected in October 2001 through November 2003. Eight parasite species were identified in the fishes consisting of 1 nematode: Raphidascaris acus (in E. lucius and S. erythrophthalmus); 1 cestode: Caryophyllaeus fimbriceps (in R. rutilus caspius and C. carpio); 2 digenean trematodes: Asymphylodora tincae (in T. tinca) and Diplostomum spathaceum (in all of the fish species except for T. tinca and S. erythrophthalmus); 2 monogenean trematodes:Tetraonchus monenteron (in E. lucius) and Dactylogyrus sp. (in C. carpio, A. bjoerkna and C. auratus gibelio); 1 crustacean: Lernaea cyprinacea (in A. bjoerkna, T. tinca and R. rutilus caspius) and 1 leech : Piscicola sp. (in R. rutilus caspius and C. carpio). The occurrence of R. acus in S. erythrophthalmus and also that of C. fimbriceps in R. rutilus caspius are reported for the first time as new host records