نشریه پژوهش های ماهی شناسی کاربردی
سال هشتم شماره 3 (پاییز 1399)

The Gobiidae are one of the largest families of fish in the world. This study aimed to investigate the morphometric characteristics of the specimens belong to three species from Gobiidae family, i.e. Acentrogobius dayi, Bathygobius meggitti and Istigobius ornatus from Makran coast, South-East of Iran. A total of 56 specimens from three Tis, Lipar and Darya-Bozorg stations during the spring and summer of 2018 were captured and transplanted to the laboratory. 36 morphological variables were analysed (including univariate and multivariate), using SPSS and PAST software. The results showed that there was a significant difference between the studied species, mainly in head and pectoral fins. But other characters were not significantly different. The results of cluster analysis showed that B. meggitti was considerably different from the others. This study also demonstrait significant intra-specific differences regarding I.ornatus species. These differences moreover than the head and pelvic fin , were seen in the tail fin. In A. dayi species, intra-specific differences, same as what observed at inter-specific level, were mainly in the head and pelvic fin’ part. A multivariate analysis of  the characters and pairwise comparision of the populations of two species I. ornatus and A. dayi showed that the populations of Lipar and Darya-Bozorg stations in both species are more similar than others. An advanced molecular study as a complementary study can help to clarify species diversity and taxonomy of these poorly known family.

In this study 12 specimens were collected from Bandar Jask, Qeshm Island and Bandare Lengeh in Hormozgan Province. DNA extraction was performed using Phenol-Chloroform method. A partial DNA sequence of Cytochrome oxidase subunit I gene (COI) was used to evaluate genetic diversity. The sequence of Cytochrome oxidase subunit I gene was done using specific primers designed based on sequences registered in NCBI GenBank. The diversity of 619 bp of COI was estimated. Gene sequencing of samples were compared with using MEGA5 and Bioedit7 software. Also, polymorphism or haplotype frequency was evaluated using dnaSp7 software. Results showed that there was low genetic distance equals to among all population and 9 haplotypes among samples were determined.

This study aimed to use mitochondrial DNA barcoding method to undrestand better toxanomic status of the Platycephalus indus and find genetic linkage with other reported specimens from different parts of the world as well as to manage the optimal utilization of native species and sustainable conservation. Sampling was performed from coastal waters of Hormozgan province. DNA was extracted from the dorsal fin using DNeasy Tissue Kit.  Phylogenetic relationships of Platycephalus indus using comparisons with those found in the NCBI Gene bank showed that samples obtained from the Persian Gulf showed a monophyletic clade along with samples from China and Saudi Arabia. In this study, it was found that the sample from the Persian Gulf and also other reported samples can be separated with the genetic distance between 0.002 to 0.095, which confirms the effective use of the COI genome in barcoding and genetic distance determination according to geographical dispersion as well as morphological characteristics. The haplotype network plot of the studied species also showed the haplotype distribution of the studied species compared to other haplotypes. Based on the obtained results, it can be assumed that the distribution of this species can be affected by the possible migration of this species.

Tench an economically important species in Anzali Lagoon has experienced a sharp catch decline in recent years. The present study aims at examining certain biological traits of the fish in Anzali lagoon. A sample of 96 pieces of such fish were netted out through gillnet fishing during Jan 2006-July 2007.  The findings showed incongruity in 11 out of 36 morphometric traits followed by 1 out of 10 numerical traits among male and female fish (p ≤0.05). Body weight of the fish varied from 40.7 up to 299.3gr with the mean figures for male and female fish at 117.8±51.0 and 117.8±54.4gr respectively. Fork length ranged from 135.2 to 255.7 with the mean 182.o±27.7 and 181.9±23.6mm for male and female fish respectively, showing no difference between them .The male fish age ranged from 2 to 7 years and for the female ones, it was 2-6.yrs with the 3-4 years as the dominant age group in both sexes. The male constituted 46.9 % of the fish population followed by 53.1% of female ones showing no major difference with the standard (1:1) ratio(x 2=0.38). In addition, the gradient of the b regression line between the body weight and fork length of male and female fish were found to be 3.21 and 2.99 respectively with isometric growth in both sexes. The average condition factor in male fish was 1.82±0.23 and 1.86±0.24 in female with the recorded relative condition factor were 0.99±0.13 in male fish and 1.01±13 in female ones revealing no differences across sexes. Absolute fecundity of 24 sample fish varied between 14000 and 154000 with relative fecundity falling between 170.1 to 644.8 pieces of egg per each gram of female fish.

To study of the some parameters of population dynamics of S. cephalus in reservoir of Shahid Rajaii dam, 591 specimens were caught by gill nets during six sampling times at 3 stations in four seasons. The most frequent catch was for season of autumn (303) and the lowest was captured in winter (43). Specimens caught for both sexes were in 6 age groups 0+ to 5+ years that, 2-year-olds were prevailing in both sexes. The sex ratio of males to females were 1:1.06, that, with not were significantly different (p>0.05, χ2=0.61). Specimens ranged from 102 to 265 mm in length and 11.59 to 241.86 gr in weight. In overall, the length and weight of the females was higher than males (p<0.05). The weight-length relationship was estimated as for females, for males, and  for the population, having a positive allometric growth in all considered groups. The Von Bertalanffy growth equations for males and females were calculated respectively Lt=27.04(1-e-0.23(t+2.03)) and  Lt=31.4(1-e-0.22(t+1.31)) that the infinity length in females was more than males. The condition factor almost was equal in both sexes (p>0.05) but was significantly different in age groups from ages 0+ to 3+ between sexes. The maximum of gonadosomatic index for both sexes was observed. The average absolute and relative fecundity were 4478.2±75.6 and 54.1±65.6 respectively. The average of female egg diameter was 0.86 ±0.12 mm in this study. Checking of relative length of the gut (RLG) showed a tendency to carnivorous feeding and Vacuity Index (CV) showed that males were relatively edacious and females were edacious. Based on Index of Fullness (IF) in both sexes and different ages, feeding conditions of this species is not appropriate. After 15 years of the formation of the lake, the view of many dynamic parameters of S. cephalus in reservoir better than river.

To study the growth patterns of Alburnoides namaki in the salt lake, For this purpose a total of 325 specimens were sampled using by By hand trawl net with two centimeters mesh (20 mm distance from node to node) in winter of 2018. Male to female sex ratio in the population studied showed There was no significant difference between males and females in studied areas (X2 Gloushjerd=0.074, X2 Yunji=0.453, X2 Tureh=1.080,). Length-weight relationship in the population Golushjerd river W=0.0097TL3.15, In the population of the Yunji river W=0.0138TL2.98 and In the population of the Turh river W=0.0062TL3.25 Was obtained. The results showed that the growth pattern of this species in the populations of Goloshjerd and Tureh river is positive allometric and In the population of the Yunji river, it was isometric (t-test, tGloushjerd = 1.73, tYoonji = 0.26, tToure = 2.67,  p < 0.05). The condition factor between ages showed that for both males and females, its highest value was observed for all ages in the Yunji river. The highest value of this coefficient was observed for male in the Gloushjerd river and Yunji river at the age of +4 and in the Toure river at +1 and +5. Maximum Growth rate In Gluoshjerd and Yunji rivers for both males and females At the age of 2+-3+ years and  In the Toure River at 1+-2+ was obtained. The von Bertolaniffy Growth model (VBGF) for the Gluoshjerd river Population Lt=172.10(1-e-0.10(t+1.70), For the Yunjji river population Lt=171.95(1-e-0.09(t+2.39) and for the Tureh river population Lt=193.30(1-e-0.07(t+2.47) was calculated.

Knowledge of fish diversity, population data and the stock size, and calculation of the amount of proper catch are essential for a wise and sustainable management of lakes. This research reports a study on fish populations in Dorudzan reservoir, Fars Province. The fish were sampled from three stations in the late Summer and mid Spring 2015, three days each, using nylon gill nets. The mean length and optimum length, condition factor, catch per unit effort, total biomass, and acceptable catch were assessed. Fish community of the Dorudzan reservoir were comprised of 8 species Cyprinus carpio, Carasobarbus luteus, Alburnus mossulensis, Capoeta aculeate, C. damascina, Hypophthalmichthys molitrix, H. nobilis, and Paniliza abu, the two last species of which are reported for the first time from this reservoir. The length-weight equations indicate a proportionate growth, except for H. nobilis whose scarce number in the samples did not allow the analyses and assessments. The condition factor was higher than 1 in all species, which confirms their proper somatic growth. The acceptable lengths for catch were calculated for P. abu (14cm), C. carpio (30cm), C. luteus (21cm), A. mossulensis (14cm), C. aculeate (24cm), C. damascina (24cm), and H. molitrix (76cm) and catch per unit efforts were 6324g for P. abu, 1260g for A. mossulensis, 2064g for C. carpio, 800g for C. aculeate, and 172g for C. luteus. Maximum acceptable catch for P. abu, C. carpio, C. luteus, A. mossulensis, and  C. aculeate in Dorudzan reservoir in 2015 were calculated as 12309, 3690, 293, 2643, and 1367 kilograms, respectively. However, according to the higher accuracy of length based assessments, they are recommended to use acceptable lengths for catch in catch regulations. Due to the continuous climate regime change and eutrophication conditions, it is highly emphasized to assess and monitor the fish populations of the lake.

The aim of this study was to evaluate the effects of different doses of magnesium-oxide nanoparticles (nano-Mg) on the growth performance, digestive enzyme activities, and some innate immune parameters in common carp fingerling (Cyprinus carpio). Nano-Mg was added to the experimental basal diets at the rates of 0 (control), 25, 50 and 100 mg/kg. Four groups of fish with an average weight of 12.96± 0.41 g were fed one of the experimental diets for 60 days. Fish that were fed diet supplemented with 25 mg nano-Mg/kg displayed improved growth performance, including final weight and weight gain, average daily gain and Specific Growth Rate (p<0.05). Feed conversion ratio was significantly lowered in fish fed with 25 mg of nano-Mg compared to control (p<0.05). Intestinal digestive enzyme activities (Amylase, Lipase and Protease) were significantly affected by dietary magnesium-oxide nanoparticles. At the end of the experiment, fish were exposed to chronic glyphosate herbicide for 14 days. Before and after stress, the highest lysozyme activity and lowest cortisol hormone level were obtained in 25 mg nano-Mg/kg diet. Liver enzymes (before and after stress) were significantly increased in the control compared to the other experimental treatments (p<0.05). According to the result of the present study, addition of 25 mg nano-magnesium per kg feed improves growth, digestive enzyme secretion and innate immunity of common carp and counteracts the adverse effects of glyphosate toxin.

The aim of the present study was to evaluate the effects of dietary Guava (Psidium guajava) leaves powder (GLP) on growth parameters, feed utilization as well as some serum parameters of common carp (Cyprinus carpio) fingerlings. Common carp fingerlings (18.88±0.27 g) were supplied and stocked in twelve fiberglass tanks at density of 14 fish per tank. Fish were fed experimental diets contains 0 (control), 2.5, 5 and 10 g per kg GLP (4 treatments with 3 replicates). At the end of feeding trial growth parameters and feed utilization (final weight, SGR and FSR) as well as some serum parameters (Serum total protein, total Immunoglobulin and alkaline phosphatase activity) were measured. The results revealed that GPL treatments significantly increased growth parameters, weight gain and decrease feed conversion ratio (P<0.05). The best growth performance was observed in 2.5 g kg-1 GPL treatment. Regardless of inclusion level, supplementation of common carp diet with GPL increased serum total protein. Evaluation of serum total Ig and ALP activity revealed remarkable increase in 2.5 g kg-1 GPL treatments compared other groups (P<0.05). According to these results it can be concluded that GPL can be considered as beneficial feed additive for improving growth performance and immune status of common carp fingerlings. However, determination of the optimum inclusion levels merit further researches.

The bony fish of the Caspian Sea are among the most important and most valuable fish in this sea, which unfortunately their reserves have been declining for many reasons in recent years. In this research, environmental factors were investigated on catching important bones such as white rutilus kutum (Kamensky, 1901), golden multitude of Chelon auratus (Risso, 1810) and Alosa saposchnikowii (Grimm, 1887). The catches were carried out by blade cooperatives on the Miankale Peninsula in Golestan Province during 73 times during the 1965-93 fishing season. In this research, 8914 whitefish, 4067 golden babies and 2335 piglets were biometric and weighed. The results showed that for goldfish with relevant data in model 5, it can be 50% for whitefish with the relevant data in model 3 can be 47% and for fish only one model with The very low coefficient of determination with a meaningful parameter yields quantities of catch per unit of effort. The results also showed that the effect of environmental parameters and spring on the average fish frequency per unit of effort was observed that the temperature factor, especially the increase of maximum temperature, was the most effect on the frequency of whitefish in the Caspian Sea, while increasing the humidity and precipitation on fish catch; Reducing the winds of the year will have the highest impact on the catching of wild boar and word. The highest catch per unit of effort was observed at 31 and 33 mm fountain.