JOURNAL OF APPLIED ICHTHYOLOGICAL RESEARCH
Year:2020 | Volume:8 | Issue:1|Papers Count:10

Population parameters of Common silver-biddy (G. oyena) were investigated in Hara Biosphere Reserve from September 2016 to August 2017. Fish were sampled by boat trawl, beach seine, and trapping barriers. Growth parameters were determined using monthly length-frequency data. Biometric parameters of 823 fish were calculated (mean total length: 8. 5± 1. 35 cm, range: 3. 9-13. 5 cm). The length-weight relationship was W=0. 0088 L 3. 21 2 (R =0. 94), which indicated the allometric growth pattern in Common silver-biddy. The value of L∞ and K were calculated to be 18 cm and 1. 5 (yr-1 ), respectively, and the growth performance index (ø ') was 2. 69. The maximum age, natural mortality rate (M), fishing mortality rate (F), and exploitation coefficient (E) were 2. 1 yr, 2. 68 yr-1, 10. 17 yr-1 , and 0. 74, respectively. Results showed that juveniles were the predominant population of this species in this region which emphasizes the supportive role of mangrove areas as nursery ground.

In this study, hepatosomatic and gonadosomatic indices and population condition of Alosa species were studied. Sampling was carried out in five stations (Rudsar, Kelachay, Chaboksar, Chamkhaleh, and Kiashahr) on the eastern coast of Guilan Province in 2016. A total of 693 fish were collected and transferred to the laboratory. Fish samples were stored in 10% formalin solution. Three species of Alosa including A. braschnikowi, A. caspia, and A. Kessleri were identified and their relative frequencies were 51. 08%, 11. 25%, and 37. 67%, respectively. Fish were divided into seven age classes (1 to 7 years old), and the highest percentage of A. braschnikowi (at age 3), A. caspia (at age 4), and A. Kessleri (at age 4) were 39. 83%, 37. 18%, 40. 23%, respectively. The highest weight and length was observed in A. braschnikowi, which were 173. 05± 75. 32g and 270. 27± 39. 38mm, respectively. The lowest weight and length was observed in A. caspia, which was 137. 53± 52. 83g and 247. 66± 32. 11mm, respectively. Population condition, gonadosomatic, and hepatosomatic indices in these three species were recorded as A. braschnikowi (0. 18± 0. 01, 0. 14± 0. 01, and 0. 12± 0. 01), A. caspia (0. 9± 0. 04, 0. 9± 0. 06, and 0. 77± 0. 03), and A. Kessleri (1. 12± 0. 02, 1. 08± 0. 04, and 1. 2± 0. 02), respectively. The sex ratio in A. braschnikowi and A. Kessleri was 1: 1 (male to female) and 1: 1. 33 in A. caspia.

This study conducted to investigate some reproductive characteristics of gibel carp (C. gibelio) in the Golestan and Voshmgir Dam Lakes from February to September 2015. During the study, 247 and 208 specimens were sampled from the Golestan and Voshmgir Dam Lakes, respectively using small beach seine. The sex ratio of captured fish from Golestan and Voshmgir Dam Lakes was 1: 10. 23 and 1: 10. 56, respectively. The highest average value of gonadosomatic index (GSI) was 12. 20% for females (in June) and 3. 28% for males (in May) in the Golestan dam. Moreover, GSI was 11. 15% for females (in June) and 2. 93% for males (in May) in the Voshmgir Dam Lake. The maximum total length and weight of gibel carp were reported 196. 00 mm and 141. 35 g (in females) and 156. 00 mm and 52. 42 g (in males) in the Golestan Dam Lake. For Voshmgir Dam Lake the maximum total length and weight were 240. 00 mm and 280. 60 g (in females) and 179. 00 mm and 81. 75 g (in males). Minimum, maximum, and mean value of absolute fecundity were 327. 71, 83134. 09, and 13272. 67 in the Golestan Dam Lake and 4857. 82, 430416. 00, and 65270. 02 in the Voshmgir Dam Lake, respectively. The mean value of relative fecundity (eggs per kg body weight) was 147. 93, 5432. 02, and 1002. 48 in the Golestan Dam Lake and 100. 94, 10722. 34, and 1283. 99 in Voshmgir Dam Lake, respectively. The average diameter of the eggs was 0. 64 mm (ranged from 0. 11 to 1. 39) in the Golestan Dam Lake and 0. 62 mm (ranged from 0. 13 to 1. 11) in the Voshmgir Dam Lake.

The present study aimed to compare the genetic diversity in offsprings derivedfrom wild, farmed, and mixed roach (R. caspicus) using five microsatellite loci(CA1, CA7, CypG27, Lid1, Rru4). A total of 90 fish (30 specimens from each population) were collected and then fixed in ethanol 96% for DNA extraction to investigate the genetic diversity. The number of alleles at offsprings derived fromdifferent broodstocks (wild, farmed, and mixed) was 10. 4, 10. 4, and 9 alleles, respectively, and indeed 29 alleles were observed in all three populations. Thenumber of effective alleles at wild, farmed, and mixed offsprings was 6. 78, 7. 58, and 6. 80, respectively. The allele frequency among wild, farmed, and mixed populations was 7, 8, and 8, respectively. The allele frequency declined inoffspring from wild broodstock due to the inbreeding and genetic drift. The mean heterozygosis (HO) was 0. 85, 0. 77, and 0. 85 in offsprings from wild, farmed, and mixed broodstocks, respectively. Also, effective heterozygosis (He) was 0. 828, 0. 859, and 0. 849 in offsprings from wild, farmed, and mixed broodstocks, respectively. Approximately, all of the loci showed deviation from HardyWeinberg equilibrium. The genetic distance among wild, farmed, and mixedoffspring populations was 0. 459, 0. 298, and 0. 684, respectively. The results of theanalysis of molecular variance revealed that the genetic diversity within the individual was 90%, while it was only 3% among them. FST value was 0. 032 thatindicated the low genetic differentiation among three populations, which might bebecause of the low number of alleles in three populations. Furthermore, NaturalMigration (Nm) between two stations was recorded at 7. 394. UPGMA clusteranalysis based on genetic distance showed that the breeding and hybrid populations were in a separate branch of the wild population branch.

There have been numerous reports on histomorphology differences of the immune system during cold and warm seasons. A total of 10 Persian sturgeons (A. persicus) (healthy and with the same size) were captured from fish ponds in International Sturgeon Research Institute (ISRI) during winter (water temperature 7. 30 ° C) and summer (water temperature 27. 90 ° C). First of all, the biometric evaluation was performed and then 0. 5 cm of anterior, middle, and posterior of intestine were trimmed and placed in formalin (10%) as a fixative solution. Then, samples were prepared using the standard histological technique and then tissue sections were cut (4-6 μ m thick slices) and stained by H&E. The results showed that in intestine the intestine-associated lymphatic tissue presence in two different forms. First, the presence of lymphatic cells scattered throughout the epithelium and second, the presence of lymphatic cells inside the lamina propria and within submucosal. In the lamina propria, the lymphatic cells had a strip shape and their density increased towards the posterior part of the intestine. Results showed a significant difference in the number of lymphocyte cells in intestinal epithelial tissue between cold and warm seasons, and their density were more in the cold season compared to the warm season. There was no sex difference in the histomorphology of intestine-associated lymphatic tissue between cold and warm seasons. These tissues can play an important role in the immune system with the production of abundant lymphocytes especially in the cold season due to the more activity.

The present study investigated the heavy metals accumulation (lead, nickel, zinc, iron, and copper) in the muscle of 180 Silver Sillago (S. sihama) from three regions of Hormozgan Province (Qeshm, Khamir Port, and Pol Port) during summer and winter. After biometrics samples were prepared using chemical digestion and the heavy metals (lead, nickel, zinc, iron, and copper) were measured using atomic absorption spectrometry. The results showed that the accumulation of lead, nickel, zinc, iron, and copper in muscle was significantly different in these three regions and also between the two seasons. The highest accumulation was observed in Qeshm in summer and winter. Moreover, the results showed that the accumulation of lead, nickel, zinc, iron, and copper was higher in summer compared to winter (in all three regions). The comparison of heavy metal accumulation in fish muscle with international standards showed that the accumulation of lead, nickel, zinc, copper, and iron were lower than FAO, WHO, and EPA standards. Food risk assessment indicated that there is no danger in the consumption of Sillago sihama with the current bioaccumulation in terms of the presence of lead, nickel, zinc, copper, and iron.

The present study aimed to investigate the effects of replacing fish meal with soybean meal and different levels of Kemin multi-enzyme on growth performance, feed efficiency, body composition, fatty acid profile, and gut lactic acid bacteria of beluga sturgeon (H. huso). Fish were fed with nine different diets (40% crude protein) including three different replacement levels of fish meal with soybean meal 0 (as control), 40, and 80% and three different levels of Kemin multi-enzyme 0, 1, and 2 g/kg. Fish were fed with the experimental diets for 12 weeks at a rate of 1% of body weight per day. The replacement of fish meal with soybean meal resulted in a reduction in growth performance and the lowest weight gain and the highest feed conversion ratio was observed in the diet with 80% replacement. The highest weight gain, higher level of enzyme (2 g/kg), and lower feed conversion ratio were observed in the diet without soybean meal. Similar results were recorded in treatment with 40% of soybean meal, indicated the positive effect of utilization of enzyme on growth performance. However, no significant difference was observed in final weight gain among different diets. Use of soybean meal (0 and 40%) and Kemin multi-enzyme (2 g/kg) showed a higher percentage of protein in fish. Fatty acid profiles and lipid content (ranged from 11. 08 to 11. 74%) had significant differences among different treatments. Fish fed with the control group and diets with enzyme supplements (without soybean meal) and diets 4 and 5 (0 and 1 g/kg enzyme and 40% soybean meal) showed the highest level of n-3 fatty acids and eicosapentaenoic acid. In contrast, diet containing 80% soybean meal without enzymes (treatment 7) had the least n-3 fatty acids, eicosapentaenoic acid, and docosahexaenoic acid. An increment was observed in the number of Lactococcus lactis, Lactobacillus carvatus, Pediococcus pentaseceous, Lactobacillus plantarum, and totally aerobic and anaerobic bacteria in all treatments. The highest number of bacterial was recorded in the diet containing 80% soybean meal and 2 g/kg enzyme (treatment 9). The results of this study indicated that the replacement of fish meal with soybean meal (up to 40%) in diet with enzyme at 2 g/kg can be suitable as a commercial diet for Beluga Huso huso.

The present study was conducted to investigate the effects of compensatory growth on growth and physiological responses (glucose, total protein, and cholesterol) of juvenile common carp (C. carpio) for eight weeks. Fish were divided into four experimental groups (initial weight; 13. 88± 0. 88 g) including 0 (T1), 2 days (T2), 4 days (T3), and a week (T4) of starvation and re-feeding periods with three replicates. At the end of the experiment, blood samples were collected from all treatments for biochemical and metabolites analysis using spectrophotometer. Results showed that the growth indices including final weight, growth rate, specific growth rate, and body weight gain were significantly different among the control and treatment 2 and 4, whereas no significant difference was observed between treatments 1 and the control. Condition factor and feed conversion ratio were not significantly different among treatments. A significant difference was observed in glucose levels between starvation treatments and the control group, although the total protein and cholesterol were not significantly different. The results of this study showed that common carp can physiologically adapt to short-term starvation and re-feeding period.

This study was carried out to investigate the effects of macroalgae Sargassum cristaefolium and Gracilaria pygmaea extracts on growth performance and blood parameters of juvenile rainbow trout (O. mykiss). Animals were randomly divided into four groups (initial weight; 0. 23 g); control group (basal diet without extracts), and three groups were fed with basal diet supplemented with 500 mg/kg S. cristaefolium (SA), 500 mg/kg G. pygmaea (GL), and 250 mg/kg S. cristaefolium + 250 mg/kg G. pygmaea (SA+GL) for 8 weeks. Fish were handfed to apparent satiation 4 times a day and fish were supplied water ad libitum, for 8 weeks. Results showed that growth factors such as final fish weight, specific growth rate (SGR), weight gain (WG), and condition factor (CF) were not significantly different among different groups. Hepatosomatic index (HSI) was significantly higher in the fish fed with control and SA diets. Hemoglobin level in fish fed with diet containing gracilaria was significantly higher than the control group. The control group had a higher level of triglycerides compared to the groups fed with diets containing sargassum or a mix of sargassum and gracilaria. Consequently, these results indicated that dietary supplementation with sargassum and gracilaria extracts had no significant effects on growth performance and blood parameters of juvenile rainbow trout.

This study was conducted to compare the morphometric, meristic characters, and biological parameters including length-weight relationship parameters and condition factor of Urmia bleak (Alburnus atropatenae) from Mahabad-Chaie, Ghale-Chaie, and Gedar-Chaie Rivers flow into Lake Urmia. A total of 20 morphometric and 7 meristic traits were measured. Morphometric data were standardized to eliminate the effects of allometric growth. One-way ANOVA analysis was used for comparison of traits. The results of morphometric data showed a significant difference in all traits except fork length, ventral-pectoral and ventral-anal distance, pre and post dorsal length, head length, and eye diameter. PCA, CVA, and Cluster analysis were performed with these traits. CVA showed that Gedar-Chaie population distinguished from other populations as confirmed by cluster analysis. Also, the studied population in terms of meristic traits showed a significant difference in branched rays of dorsal and anal fins lower gill rakers. Also, length-weight (LWRs) parameters and condition factor were estimated. Based on the results, b values were 3. 26 and 2. 75 also condition factor were calculated 1. 02 and 1. 18 for the Mahabad-Chaie and Ghale-Chaie populations, respectively. A higher condition factor reflects the relatively favorable condition of their habitat in the studied rivers.