JOURNAL OF APPLIED ICHTHYOLOGICAL RESEARCH
Year:2020 | Volume:8 | Issue:3|Papers Count:10

Gobiidae is one of the largest fish families in the world. This study aimed to investigate the morphometric characteristics of three species from Gobiidae family icluding Acentrogobius dayi, Bathygobius meggitti, and Istigobius ornatus from the Makran coast, southeastern of Iran. A total of 56 specimens were captured from three stations including Tis, Lipar, and Darya-Bozorg during the spring and summer 2018 and transplanted to the laboratory. Thirty-six morphological variables were analysed (including univariate and multivariate) using SPSS and PAST software. The results showed that there was a significant difference among the studied species, mainly in the head and pectoral fin. However, other characters were not significantly different. The results of the cluster analysis showed that B. meggitti was considerably different from the other species. This study also demonstrates significant intra-specific differences regarding I. ornatus. In addition to the head and pelvic fin, some differences were observed in the tail fin. In A. dayi, intra-specific differences, same as what observed at inter-specific level, were mainly in the head and pelvic fin. The multivariate analysis of the characters and pairwise comparison of the I. ornatus and A. dayi populations showed that these two populations in the Lipar and DaryaBozorg stations have more similarities. An advanced molecular study as a complementary study is required to clarify the species diversity and taxonomy of this poorly known family.

In this study, 12 specimens were collected from Bandar-e Jaask, Qeshm Island, and Bandar-e Lengeh in the Hormozgan Province. DNA extraction was performed using the Phenol-Chloroform method. A partial DNA sequence of cytochrome oxidase subunit I gene (COI) was used to evaluate the genetic diversity. The sequence of COI was performed using specific primers designed based on the sequences registered in NCBI GenBank. The diversity of 619 bp of COI was estimated. The sequence of the gene was compared using MEGA5 and Bioedit7 software. Also, polymorphism or haplotype frequency was evaluated using dnaSp7 software. Results showed that there was a low genetic distance among all populations. In addition, nine haplotypes were identified among the studied samples.

The present study aimed to solve the taxonomic problems of Bartail flathead (Platycephalus indicus) using mitochondrial DNA barcoding method. In addtion, the genetic relationship of P. indicus with other reported Bartail flathead (P. indicus) from different parts of the world was investigated for better management and sustainable conservation. Sampling was performed from the coastal waters of the Hormozgan Province. DNA was extracted from dorsal fin using DNeasy Tissue Kit. For phylogenetic analyses of Bartail flathead (P. indicus) the data were compared with those found in the NCBI Gene bank. The results showed that the collected samples from the Persian Gulf had a monophyletic clade along with collected samples from China and Saudi Arabia. It was found that the Bartail flathead (P. indicus) collected from the Persian Gulf and other reported Bartail flathead (P. indicus) from other regions can be separated with the genetic distance of 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 migration patterns of this species.

Tench is an economically important Cyprinids species in the Anzali Lagoon, however, the capture fisheries of this species have dramatically decreased in the recent years. The present study aimed to examine certain biological traits of Tench in the Anzali lagoon. Ninety-six fish were captured by gillnet fishing from January 2006 to July 2007. The findings showed incongruity in 11 out of 36 morphometric traits followed by 1 out of 10 numerical traits between male and female. Body weight of the fish varied from 40. 7 g to 299. 3 g with the mean weight for male and female was 117. 8± 51. 0 g and 117. 8± 54. 4 g, respectively. Fork length ranged from 135. 2 to 255. 7 mm and no significant difference was observed between male (182. 0± 27. 7 mm) and female (181. 9± 23. 6 mm). The male fish age ranged from 2 to 7 years and the female age ranged from 2 to 6 years, the 34 years was the dominant age in both sexes. The male constituted 46. 9 % of the population followed by 53. 1% female, showing no major difference with the standard (1: 1) sex 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 were found to be 3. 21 and 2. 99, respectively, with an isometric growth in both sexes. No significant differences were observed in the average condition factor (male: 1. 82± 0. 23; female: 1. 86± 0. 24) and relative condition factor (male: 0. 99± 0. 13; female 1. 01± 13) between male and female. The absolute fecundity of 24 examined fish varied from 14000 to 154000 with a relative fecundity falling from 170. 1 to 644. 8 pieces of egg per each gram of the female body weight.

To study some population dynamic parameters of the Chub (S. cephalus) in the Shahid Rajaii Dam Lake, five hundred and ninety one fish were captured by gill nets (mesh size: 10, 20, 30, 40, and 50 mm) from three stations. The most frequent catch was in autumn (303) and the lowest was in winter (43). The captured fish were divided into six age groups, 0+ to 5+ years for both sexes and 2-year-olds were prevailing in both sexes. The sex ratio of female to male was 1: 1. 06. The length of animals ranged from 102 to 265 mm and the weight ranged from 11. 59 to 241. 86 g. In overall, the length and weight of the females were higher than males. The weightlength relationship was estimated as for females and for males, and for the population. Growth pattern, in all considered groups, was calculated isometric. The Von Bertalanffy growth equations for males and females were Lt=27. 04(1-e-0. 23(t+2. 03) ) and Lt=31. 4(1-e-0. 22(t+1. 31) ), respectively and the infinity length in females was higher than males. A significant difference was observed in the condition factor in both sexes. The relative length of the intestine showed a carnivorous diet for this species. 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. The comparison of results of this study with the Tajan River population show that many biological parameters of this species in the Shahid Rajaii Dam Lake were more favourable than those in the Tajan River.

To study the growth patterns of Alburnoides namaki in the salt lake, a total of 325 specimens were captured by a 2 cm mesh size (20 mm distance between two nodes) hand trawl net in winter 2018. The male to female sex ratio in the studied populations showed no significant difference between male and female. Lengthweight relationship in the Golushjerd River, Yunji River and Turh River populations were W=0. 0097TL 3. 15, W=0. 0138TL 2. 98 and W=0. 0062TL 3. 25, respectively. The results showed that the growth pattern of this species in the Goloshjerd River and Tureh River populations were positive allometric and in the Yunji River population was isometric. The highest condition factor among all ages for both sexes was observed 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. The maximum growth rate was obtained in the Gluoshjerd River and Yunji River for both sexes at the age of 2+-3+ years and 1+2+ years in the Toure River. The Von Bertalanffy growth function (VBGF) for the Gluoshjerd River, Yunjji River, and Tureh River populations were Lt=172. 10(1-e-0. 10(t+1. 70) ), Lt=171. 95(1-e-0. 09(t+2. 39) ), and Lt=193. 30(1-e-0. 07(t+2. 47) ), respectively.

Knowledge of fish diversity, population data, stock size, and calculation of the sustainable fishery is essential for successful and sustainable management of lakes. This research reports a study on fish populations in the Dorudzan Dam Lake, Fars Province. Fish were captured from three stations in the late summer and mid spring 2015 (three days for each sampling) using nylon gill nets. The mean length and optimum length, condition factor, catch per unit effort, total biomass, and acceptable catch were assessed. The fish community of the Dorudzan Dam Lake included 8 species Cyprinus carpio, Carasobarbus luteus, Alburnus mossulensis, Capoeta aculeate, C. damascina, Hypophthalmichthys molitrix, H. nobilis, and Paniliza abu (the two last species are reported for the first time from this Dam Lake). The length-weight equations indicate a proportionate growth, except for H. nobilis which the low number of 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 as P. abu (14cm), C. carpio (30cm), C. luteus (21cm), A. mossulensis (14cm), C. aculeate (24cm), C. damascina (24cm), and H. molitrix (76cm). Catch per unit effort was 6324 g for P. abu, 1260 g for A. mossulensis, 2064 g for C. carpio, 800 g for C. aculeate, and 172 g for C. luteus. The maximum acceptable catch for P. abu, C. carpio, C. luteus, A. mossulensis, and C. aculeate were 12309, 3690, 293, 2643, and 1367 kilograms, respectively. However, due to the higher accuracy of length based assessments, it is recommended to use the acceptable lengths for the catch. Due to the continuous climate regime change and eutrophication conditions, annually fish populations monitoring is recommended in this lake.

This study aimed to evaluate the effects of different dosages of magnesium-oxide nanoparticles (nano-Mg) on the growth performance, digestive enzyme activities, and some innate immune parameters in common carp fingerling (C. carpio). NanoMg 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 with the experimental diets for 60 days. Fish that were fed diet supplemented contain 25 mg nano-Mg/kg displayed improvement in growth performance, including final weight and weight gain, average daily gain, and specific growth rate. The feed conversion ratio was significantly lowered in fish fed with 25 mg of nano-Mg compared to the control group. Intestinal digestive enzyme activities (amylase, lipase, and protease) were significantly affected by dietary magnesiumoxide nanoparticles. At the end of the experiment, fish were exposed to chronic glyphosate herbicide for 14 days. Before and after the stress, the highest lysozyme activity and lowest cortisol 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 groups. According to the result of the present study, the addition of 25 mg nano-magnesium per kg feed improves growth, digestive enzyme secretion, and innate immunity of common carp and counteracts the adverse impacts of glyphosate herbicide.

The present study aimed 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 (C. carpio) fingerlings. Common carp fingerlings (18. 88± 0. 27 g) were supplied and stocked in twelve fibreglass tanks at a density of 14 fish per tank. Fish were fed experimental diets contains 0 (control), 2. 5, 5, and 10 g per kg GLP (four treatments with three replicates). At the end of the 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 investigated. The results revealed that GPL treatments significantly increased growth parameters, weight gain, and decrease the feed conversion ratio. The best growth performance was observed in 2. 5 g kg-1 GPL treatment. Regardless of the inclusion level, supplementation of common carp diet with GPL increased serum total protein. Evaluation of serum total Ig and ALP activity revealed a remarkable increase in 2. 5 g kg-1 GPL group compared to other groups. According to these results, it can be concluded that GPL can be considered as a beneficial feed additive for improving growth performance and immune status of common carp fingerlings. However, determination of the optimum inclusion levels merits further researches.

Climate change can directly or indirectly affect the presence and distribution of aquatic organisms. In this study, the effect of environmental factors on the quality and quantity of dominant bony fish catching such as kutum (R. kutum), golden mullet (C. aurata), and Alosa sp. has been investigated in the coastal region of the Golestan Province. The catches data were carried out with 73 times beach seine hauling by fishing cooperatives on the Miankaleh Peninsula in the Golestan Province during the 2017-18 fishing season. In this research, 8914 R. kutum, 4067 C. aurata, and 2335 Alosa sp. were collected for biometric analyses. The results showed that the absolute frequency of C. aurata had the best significant characterized by parameters such as time, minimal temperature, mesh size, humidity, and hauling time in the model of F= 206. 29 – 43. 1 time – 1. 35 Tmin – 3. 07 Mesh – 0. 64 Humidity – 10. 52 tstart, R2 = 0. 50. For R. kutum the absolute frequency had the best significant characterized by parameters such as time, hauling time and mesh size in the model of F=92. 2 + 77. 23 time – 27. 59 tstart + 4. 06 Mesh, R2 = 0. 47 and for Alosa sp. by hauling parameter in the model of F= 14. 91-6. 965 time to start, R2=0. 026.