JOURNAL OF APPLIED ICHTHYOLOGICAL RESEARCH
Year:2016 | Volume:4 | Issue:1|Papers Count:8

In order to determine some parameters of population dynamics of C. damascina captured from Rudbal River, Fars Province, 183 specimens were collected. Five age classes, ranged from 1+ to 5+ years, and the highest frequency was belong to one years old in both sexes. The overall sex ratio was 1 : 1.28 (males:females). The length and weight range of fish in Rudbal River were recorded from 55.35 to 245 mm and 2.05 to 158.93 g, respectively. Accordingly, the length- weight relationship was measured as W = 0.00002L2.84 for males, and W = 0.00001L2.94 for females. The Von Bertalanffy growth equation was estimated as; Lt=17.061(1 - e-0.651(t +0.108) ) for males and Lt=34.94 (1 - e-0.19 (t +0.05) ) for females, and consequently, the infinity length in females was remarkably more than males. The condition factor and factor relative status of different ages showed that the value of these factors is higher than in males and females respectively, and these increases with age in both sexes. Natural mortality rate was calculates as 1.38 and 0.273 in males and females, respectively. Absolute fecundity and relative fecundity in caught females were determined as 4392±1361 and 55.39±30.35, respectively. Relative Length of Gut was revealed that this fish is herbivorous and Fullness index in both sexes at different ages showed that its feeding status is fairly poor.

The aim of this study was to record growth parameters, age structure and sex ratio of Broodstock of roach (Rutilus caspicus) from East coast of the Caspian Sea. For this purpose, 290 samples were caught by trap (26 mm mesh size) during February 2015 to May 2015. The age rang were 1+ to 4+ years for male and female among which 59.45% of age composition was belonging to year classes of 2+ and 35.75% of age composition was belonging to year classes of 3+. Female to male sex ratio was obtained 1:1.61 which was a significant diference (p= 0/000). Fork length (FL) and weight (W) ranged from 125 to 214.79 and 135 to 270 mm and 29.03 to 188.3 and 43.67 to 293 g for male and female, respectively. The b value of using FL was calculated as 3.039 and 3.197, respectively, and the growth pattern was isometric in the male fish (p>0.05) and positive allometic in the female fish (p< 0.05). Mean of relative weight (Wr) was calculated as 1.016±0.109 and 1.127±0.173 for male and female, respectively, that was differed significantly (p<0.05). Instantaneous growth coefficient (G) was obtained as 0.31 and 0.51 for male and female, respectively. These results showed that environmental condition are not suitable for Broodstock of Roach (Rutilus rutilus caspicus) in southeastern coast of the Caspian Sea and a serious and continuous protection from natural spawning rivers and ponds during migration and spawning season is needed.

This study aimed to determine the feeding habits and diet of Alburnusmossulensis in the Abgarmeh River in Saleh Abad, Ilam Province, in different seasons of 1386-1387.Sampleincludes fifty five A. mossulensis which were caught using Cast net (mouth diameter: 3mm; mesh size: 20mm) and Scoop net (mesh size: 2mm) from 4 stations. The length range of fishes in the sample was 4.70-14.50 cm. In this study obtained the digestive of A.mossulensis were Odonata (138), Diptera (165), Hemiptera (91), Amphipoda (75), Trichoptera (35), Ephemeroptera (95), Coleoptera (62), Oligochaeta (89), Plecoptera (34) and Hirudinea (50) respectively. The highest and lowest abundance of food in the digestive tract were of the Diptera (19.78%) and the Plecoptera (4.07%), respectively. According to the frequency of food groups in the river and the results of digestive tract of fish, it was determined that this fish has tendency to Coleoptera (0.029) and Trichoptera (0.023) and the lowest desire to Amphipoda (-0.053). Average relative length of the intestine (1.095±0.81g) and fullness index of A.mossulensis (946.68±76.97) were higher in spring than those observed in other seasons. Also, the mean condition factor index was higher in winter (795.06±24.99) than that of other seasons. After investigating the gastrointestinal tract it was found that of the 55 cases studied the that all the fish were full stomach. According to the results, A. mossulensis in the Abgarmeh River from Ilam province is a gobbler and omnivorous species who has greatest tendency to Coleoptera and Trichopteraand as its food and the least desire to Amphipoda. This species also has extremely high nutritional.

Contaminants, such as heavy metals, accumulate in fish tissues and organs after entering into aquatic ecosystems. These heavy elements are eventually enter the food chain and causes too much problems for aquatics animals and human. In this study, the accumulation of heavy metals (Cu, Zn, and Pb) in liver and muscle samples of Yellowfin seabream (Acanthopagrus latus) caught from fishing port of Deylam were quantified. The concentrations of heavy metals were determined using Atomic Absorption Spectrophotometry (PG-AA500). Concentrations of Lead, Zinc and Copper in the liver and muscle in spring and summer showed significantly difference (p<0.05). The study revealed that seasonal variation influenced the concentration of metals in the samples. Muscle, generally, accumulated the lowest levels of metals in every season and also the highest metal concentrations were observed in the liver (229.19 ± 26.57 mg. g -1 Zn) in winter. Generally, there were significant seasonal changes for Pb, Zn and Cu concentrations in the tissues (p<0.05). The average concentration of Cu, Zn, and Pb was observed respectively 1.51, 12.1 and 6.75 mg. g -1 dry weight. The Pb accumulation in the muscles of fish were higher than permissible limit of WHO. However, the concentrations of copper and zinc were lower than permissible limit of WHO.

This study focused on investigating the synergistic effects of potassium sorbate and Lactobacillus casei in rainbow trout fry (Oncorhynchus mykiss) with the initial weight of 2.45±0.05.A completely random designed experiment was carried out for 8 weeks using six treatments, including: commercial diet (control), diet 107 CFU/ g bacteria (treatment 1), a diet containing 0.5% of potassium sorbate (treatment 2), a diet containing 1% potassium sorbate (treatment 3), the composition of the diet with %0.5 of potassium sorbate and 107 CFU/ g Lactobacillus casei (treatment 4), and the composition of the diet with 1% potassium sorbate and 107 CFU/ g Lactobacillus casei (treatment 5).The results showed that the highest final weight, SGR, FCR and PER were observed in the treatment 4 which revealed significant differences with other treatments (P<0.05). However, no significant differences were observed between the different treatments regarding the carcass structure (P>0.05). WBC was significantly higher (P<0.05) in T4 compared with the other groups. No significant difference in the amount of RBC, Hb, HCT, MCV, MCH, MCHC were observed (P>0.05). In addition, the number of intestinal bacteria and lactobacillus showed significant differences among the different treatments. and highest rate was observed in treatment 4 (P<0.05) In total, according to the results and the positive observed effects, the addition compound CFU/ g 107 bacteria (Lactobacillus casei) and 0.5% of potassium sorbate in the diet of rainbow trout diet is recommended.

This study evaluated the effect of dietary administration Lactobacillus brevis MF01 on hematology parameters and survival in S. lucipercaafter exposure to Aeromonas hydrophila. The fed fish with dietary administration containing A1 (L.brevisMF01 1010 CFU/ g), A2 (L. brevisMF0118CFU/ g) and the control group (without Lactobacillus) were investigated for 45 days. At the end of the feeding period, the fish were take blood and then were challenged with 4.5× 108CFU/ml A. hydrophila. Fish were monitored daily and rate of survival was recorded over a period of 7 days post challenge. The hematology results showed that feeding with supplemented L. brevis (108, 1010cfug-1) and control group had no significant difference. After being exposed to A. hydrophila, the lymphocytes in the probiotic treatments were higher than the control group and the neutrophils in injected control group were significantly higher than probiotic groups. The survival rate, after exposure of the probiotic treatments, were higher than that in the injected control group.

The study of fishes in aquatic ecosystems is crucial from different aspects, including ethological, ecological, management and preservation of the natural resource, stocks exploitation and aquaculture. Thus, to survey population structure in Mosul bleak (Alburnus mossulensisHeckel, 1843) in ten rivers in Karun River basin, in summer 2009, 195 specimens were captured by a seine net. Twenty-two morphometric characteristics were measured by a digital caliper and 14 meristic characteristics were counted under a binocular. Initially, to remove the size effects caused by allometric growth pattern, values of morphometric characteristics were standardized. Differences between populations were analyzed using analysis of variance (ANOVA), Duncan test, principle component analysis (PCA) and canonical variate analysis (CVA). Lengths of specimens were between 27.9-160.2 mm. Among the morphometrics, 21 and among the meristics, 13 characteristics, were significantly different among the populations (P<0.05). Three first components were responsible for 75.68% of variances in studied populations. Canonical variate analysis showed Khersan, Ivan-e Abbasi and Darband rivers were different from other populations. Beside, although specimens from Bashar and Marbor rivers were overlapping with populations from Banestan, Shirvan, Dopolan, Aligodarz and Sepidar rivers, these three populations were different from each other. The results of this study showed that morphometric and meristic characteristics are able to differentiate Mossul bleak populations from each other.

In this study the effects of two probiotic bacteria, namely Bifidobacterium animalis and B. lactisin, with the three concentrations of 1×109 (T1), 2×109 (T2), and 3×109 (T3) CFU 100g-1, on growth performance and survival of rainbow trout larvae with initial body weight of 0.538 ± 0.197g were evaluated in comparison with the control (without probiotic) during a 60-day study. This research was designed with a control and three experimental treatments with three replications. Among all the treatments, T1 showed the highest growth (p<0.05). In addition, a significant difference was observed between experimental treatments and the control with regard to growth and nutritional parameters and also body composition (p<0.05). The survival percentage of the larvae was significantly higher in experimental treatment in comparison with the control. The results of this study showed that the use of B. animalis and B. lactis could improve growth performance and decrease mortality rate during rainbow trout larviculture.