samad darvishi

The purpose of this study is to investigate the effect of hotel features performance on electronic oral marketing behaviors (studied in Kish Island hotels). The present research is applicable in terms of purpose and descriptive-survey in terms of nature and method of data collection; and is specifically based on structural equation modeling. The statistical population of the study is all customers of Kish Island hotels, which are 54 hotels and apartment hotels in the first six months of 2020. According to surveys, about 200 people have stayed in these hotels in the last 6 months, and based on the available community and Cochran's formula, 322 people have been selected by cluster sampling method as a sample. Two questionnaires were used as collection tools in the present study, including the Hotel Reputation Performance Questionnaire from Khan et al.'s (2017) questionnaire and word-of-mouth e-marketing questionnaire from the standard word-of-mouth advertising questionnaire of Bamboer et al. (2011). Findings showed that the performance of hotel features has a significant effect on word-of-mouth e-marketing behaviors. Hotel environment and facilities have a significant impact on word-of-mouth e-marketing behaviors. The competence of hotel staff has a significant effect on wordof-mouth e-marketing behaviors. The hotel-to-guest experience has a significant effect on word-of-mouth e-marketing practices. Hotel location has a significant effect on word-of-mouth e-marketing behaviors.

A bioassay was conducted to investigate the effect of static magnetic field on hatching function of kutum (Rutilus kutum) in Veis incubators. For this purpose, three experimental treatments were conducted in triplicate with magnetic flux densities of 5, 15 and 25 milli-tesla along with control treatment (fish without exposed to the magnetic field). The obtained eggs from 8 female broodstock were randomly transferred to the incubators with density of 49,000 eggs in each incubator. Changes in water physicochemical parameters including water temperature, pH, dissolved oxygen, total hardness, nitrogen derivatives (ammonia and nitrite) and phosphate levels were daily evaluated during the incubation period. At the end of the incubation period, hatched larvae from each treatment were transferred to 100-liter Zug incubators without any magnetic exposure for monitoring their growth. The results of this study showed significant differences in total hardness, ammonia and dissolved oxygen concentration of water among the treatments (p<0.05). By considering the physiological characteristics of kutum, the best effect of static magnetic field was obtained in the 25 milli-tesla treatment. Besides, the number of hatched larvae in 25 milli-tesla treatment was significantly higher than the control treatment. However, there was no significant difference in the survival rate of larvae before yolk sac absorption among the experimental treatments (p>0.05). The results of this study showed that static magnetic field could have positive effects on water quality and survival rate of kutum larvae.

The success of artificial reproduction requires rapid assessment of fish sperm characteristics followed by the ovum. This study was conducted to investigate relationship between sperm characteristics including semen volume, percentage of motile sperm, sperm motility, sperm density and spermatocrit with morphological characteristics of male broodstocks of Caspian kutum (Rutilus kutum). Forty males (3-4 years) were randomly selected from the fish captured in the west-southern of the Caspian Sea and their Spermatological parameters (semen volume, sperm density, sperm motility, percentage of motile sperm, and spermatocrit) and some morphological characteristics (weight and fork length) were individually determined. The average weight and fork length of the fish were 758.00±49.20 g and 40.35±3.72 cm, respectively. In addition, each fish had sperm volume of 2.15±0.27 mL with motile percentage of 75.36±8.65%. Sperm motility, sperm density, and spermatocrit were 41.45±3.48 s, 14.93±1.21 ×109 mL-1, and 89.75±2.45 %. The results showed that spermatocrit had significantly positive correlation with fork length (0.886) and (0.886) body height of the fish. A significant negative correlation was also obtained between fork length and sperm density (-0.829) showing a decrease of sperm density by increasing fork length in the Caspian kutum. The results of the present research showed that fork length and body height could be used as appropriate indices for identification of sperm density and spermatocrit in Caspian kutum, whereas fish weight had no significant correlation with spermatological parameters.

This study was conducted to investigate the growth pattern and ontogeny of the activity of alpha amylase enzyme in common bream (Abramis brama) from hatching through 60th day post hatching (dph) at the Shahid Ansari breeding and restocking center (Rasht, Guilan, Iran). The results showed that wet weight and total length of common bream were 0.65 ± 0.03 mg and 4.66 ± 0.24 mm at hatching, respectively. The growth pattern from early development through 60th dph was exponential as Y = 5.9558e0.0346xand R² = 0.97. The results also revealed that alpha- amylase enzyme was present at the hatching and its activity was constant till 4th dph and had an increasing trend till 25th dph. Then, a significant decrease was observed in the activity of this enzyme on 35th dph; thereafter its activity showed an increasing trend till 60th dph. In addition, the activity of alpha-amylase showed a strong relationship with increasing the age of specimens. The results also revealed that ontogeny of the alpha-amylase in common bream larvae are similar to that of other omnivorous and herbivorous fishes. It can be concluded that the food with higher content of carbohydrate can be used after 12th dph for feeding of their larvae.

Effect of myrtus extract (Calendula officinalis) at concentrations of 0.5, 1 and 1.5% in diet was studied on some growth performance, survival and immunological variables of gold fish (Carassius auratus) weighing 8.5±1 g for 60 days using a complete random design. A number 63 fish were used per treatment and growth parameters consisting of percent body weight increase, specific growth rate, daily growth rate and condition factor were evaluated. The blood samples were obtained at the end of trial and levels of hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, heterophil, lymphocyte, and complement activity were also measured. The obtained results showed that an insignificant increase was seen in level of complement component when the concentration of myrtus extract was increased in the fish diet (p>0.05). The amounts of C3 and C4 were also higher in treatments containing the extract than control group but they had on significant different (p>0.05). Generally, the results of this experiments showed that Calendula officinalis extract had positive effect on some immunological parameters of fish and it could act as immonostimulator in this fish species.

In recent years, there has been an apparent increase in the occurrence of harmful algal blooms. The potential of barley (Hordeum vulgare L.) straw extract to inhibit algal growth was assessed. Algal growth in water of Anzali lagoon was inhibited by the addition of barley straw (1% volumetric), with the chlorophyll a concentration remaining below the original level (40 µg l-1) throughout the experiment. In contrast, in the presence of wheat straw, algal biomass increased, reaching a final chlorophyll a concentration of 1160 µg l-1 after 28 days. Analysis of the remaining particulate straw at the end of the experiment showed that the lignin content of barley straw had increased significantly (p<0.05). Beside, the bioassays, which were conducted to determine the efficacy of barley straw in controlling algal growth of 10 freshwater species, the results indicated that barley straw liquor inhibited the growth of three nuisance algae common in freshwater: Synura petersenii, Dinobyron sp., and Microcystis aeruginosa. However, the growth of Selenastrum capricornutum, Navicula sp., Spirogyra sp., and Oscillatoria lutea were significantly (p<0.05) increased in the presence of the straw liquor. The growth of remainder, Ulothrix fimbriata, Chlorella vulgaris, and Anabaena flos-aquae, showed no significant (p<0.05) difference from controls.