Journal of Animal Research
Year:2018 | Volume:31 | Issue:2 |Papers Count:10

As a chemical stressor, increasing ammonia concentration in water can causes nonspecific physiological responses in fish. The present research was done to determine the suitable amount of ammonia and its effects on hematologic, stress factors and histology of gill in banded cichlid (Heros severus). For this purpose, 1 control group and 5 treatments of ammonia (0. 1, 0. 2, 0. 4, 0. 8, and 1. 2 mg/l) with three replicates were selected. 180 specimens were transported to different concentrations of ammonia in 50-liter tanks for 12 hours. After blood sampling, hematologic and stress factors were measured. In addition, their gill tissues were sampled. The results showed that white blood cells reached its peak in Treatment 3 (P<0. 05). The lowest red blood cells were observed in Treatment 5 (P<0. 05). When concentration of ammonia was increased, the amount of HB, Htc, MCV, MCH, MCHC, Monocytes and eosinophils didn’ t have significant difference (P>0. 05). The results showed that cortisol increased in the first two treatments and then decreased in the next three treatments. In addition, glucose reached its minimum level in the first treatment and then showed a significant increase in other treatments (P<0. 05). The most tissue damages were observed in Treatment 5 along with hypertrophy of lamella epithelial cells, adhesion of lamellae, lamella detachment and bulging, filament epithelium necrosis, severe necrosis in the lamella and filament epithelial, and necrosis and demolition of pillar cells. Therefore, it is better for banded cichlid to the amount of ammonia does not increase more than 0. 1 mg/l.

Habitat fragmentation is a dynamic process that changes the pattern of habitats in the landscape, decreases biodiversity and increases inbreeding. Isolation of small populations consider as a serious threat to the protection of animals, particularly in carnivorous animals. In this regard, habitat suitability modeling is an important tool to identify distribution and dispersion of species and effective factors on them. The striped hyaena (Hyaena hyaena) is one of the least known bulky carnivores of Iran. It has played an important roles for energy flow in ecosystems. The aims of present study are investigation of habitat suitability of striped hyaena using MaxEnt and neural network models in Haftad Gholeh, Arak protected area. For this purpose, 45 points of presence, 30 points of absence and 24points of presence of denning regions of species and 16 points of absence of denning which were used as a main factor and 11 effective variable. Models are validated using ROC (Receiver Operating Characteristic curve) statistical approaches. The results illustrate although both models succeed in prediction suitable habitat area and the selection of den of striped hyaena but according to the ROC in MaxEnt model the amount of AUC for suitable habitat and denning regions has obtained AUC=0. 78 and AUC=0. 76, respectively. As well as that, in ANN model the amount of AUC for suitable habitat and denning regions has been obtained AUC=0. 69 and AUC=0. 65, respectively. So results of current study showed the power of evaluate and prediction of MaxEnt model is higher than ANN model and it is near to the fact. Based on the result of jackknife sensitivity analysis, the most effective variables on habitat suitability modeling were the type of vegetation, distance from spring and soil type. According to the result of influence order in ANN, variables such as aspect, den, and distance of aqueduct are considered as effective variables, respectively. Based on the result of both Maxent and ANN models, the most important effective variables in the selecting of den for striped hyaena in the Haftad Gholeh protected area was uses of rangelands.

Sturgeon fish are of great commercial value belong to one of the most ancient groups of the osteichthyes. With the aim of studying and comparing retina structure and its importance in fishes, Acipenser stellatus, has been selected as a benthic lacking sufficient color vision and visual acuity. It is assumed that fish eye can be well adapted to the environment and feeding behavior. For this purpose histological sections of eye were prepared using paraffinin method and stained by hematoxyline-eosin Observation by light microscope and SEM showed that Acipenser stellatus retinal photoreceptors were all comprised of cone cells and without rod cells were not present. The number of cone cells in dorso – temporal quadrant was more compared to others it. Single and double cones were found. Low Diversity and few number of cone cells proved weak vision ability and low dependence on color vision in this fish.

Considering the importance of iron and the role of oxidative stress in its toxicity, the purpose of this study was to compare the effect of iron nanoparticle and Zataria multiflora essential oils on the activity of biochemical markers of the liver, also activity of CYP450 and GST enzymes was examined in this study. The adult male rats were divided into 5 groups and 3 subgroups, including negative control group receiving normal saline, positive control group receiving 200 mg/kg of iron nanoparticles, and treatment group receiving Zataria multiflora essential oils. The rats received 100 mg/kg b. w and 200 mg/kg b. w of Zataria multiflora E. O intraperitoneally. Then rats were killed, and their liver tissue was removed for pathologically and biochemically analyze. In the analysis of AST marker after 72 hours, the injection of iron nanoparticles resulted in an increase in activity of these markers, which shows the hepatocellular injury, and the injection of nanoparticles after 72 hours reduced the activity of CYP450 and GST enzymes. It was found that the treatment of rat animal with Zataria multiflora E. O reactivated the liver marker and GST enzyme. Necrotic foci developed by the damage to iron nanoparticles in hepatocytes were reduced by the treatment with Zataria multiflora E. O. So, the use of iron nanoparticles results in damages to the liver tissue and increases in metabolism of xenobiotics, and the treatment with the Zataria multiflora essential oil can prevent and resolve these damages.

Study on pellets is one of the best non-invasive methods to determine nutrient contents which have been eaten by a predator bird. The purpose of this study was to examine the diet and food niche overlap in the Little Owl (Athene noctua) and Common Kestrel (Falco tinnunculus) in Shir-Ahmad Wildlife Refuge, Sabzevar. After completing field surveys, pellets were transferred to laboratory. Then, these pellets were separated by soaking. Then prey remains in pellets were separated and indentified. The percentage of each food item was calculated in relation to total number of pellets. In addition, the weight, length, and diameter of pellets, the percentage of prey biomass, the food niche breadth, species diversity, species evenness, and food niche overlap were calculated. Based on total 548 pellets collected of the Little Owl, the diet was consisted of beetles (13. 78%), locusts (15. 02%), birds (5. 02%), small mammals (18. 13%), rodents (18. 55%), shrews (6. 42%), reptiles (0. 7%) and ants (2. 79%), respectively. Analysis of 206 pellets of the Common Kestrel showed that the diet was consisted of beetles (24. 92%), locusts (25. 55%), birds (6. 54%), small mammals (15. 89%), rodents (13. 71%), shrews (3. 12%), reptiles (4. 98%) and ants (5. 30%), respectively. In this study, the food niche overlap of the Little Owl and Common Kestrel based on the percentage of overlap's measure, Pianka's measure, and Horn's index was 88. 51%, 0. 98, and 0. 96, respectively. Results of this study showed that food niche overlap between the Little Owl and Common Kestrel was high.

Heavy metals can produce various pathophysiological effects in aquatic animals. In this study, the effect of different water-borne copper concentrations on bahaii loach (Turcinoemacheilus bahaii) metabolism was investigated. Lethal concentration (LC50-96h) of copper was determined for this species according to OECD, 203 protocols. Based on LC50-96h (1. 189 mg/l), 40 fish (1. 6± 0. 56 g) were divided into five different groups, including control and different concentrations of copper (24h, 0. 910 mg/l), (7d, 0. 455 mg/l), (14d, 0. 182 mg/L) and (30d, 0. 091 mg/l). Then, by using intermittent-flow respirometer, the oxygen consumption of each individual fish was recorded to calculate standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS). Results showed significant (P<0. 05) reduction in SMR of fish, exposed to copper. The minimum SMR was obtained following 30days exposure to copper (43. 90 ± 14. 86 mgO2/kg/h), which was reduced by about 70%, as compared to control group (148. 10 ± 12. 73 mgO2/kg/h). Although MMR were remained unchanged following all copper treatments, AS in copper-treated fish (14d) showed a significant increase (P<0. 05) in comparison with control group. According to the results, it seems that copper could disrupt fish metabolism and subsequently, changes the energy budget of fish, required for biological activities such as growth, feeding and reproduction.

Western whiteleg shrimp (Penaeus vannamei) is the most important marine farmed shrimp species in Iran. Because this species is non-native shrimp, provision of broodstocks totally rely on imports from the main producing countries. The culture of broodstocks under Iran's condition is considered as one of the main aspects of developing this industry. So, the morphometric relationship between total length and total body weight and also condition factor of cultured female whiteleg shrimp were analyzed during grow out phase, starting from 70 to 290 days of semi-intensive culture in earthen ponds. Regression lines between total length and total body weight were significantly different among seasons. Shrimps demonstrated the same body weight increase values in autumn and spring. So, the same regression line was considered as BW=0. 0049TL3. 2096 for these two seasons. This line for winter (BW=0. 11TL1. 9668) was significantly different from the both previous mentioned seasons. On the other hand, the female shrimps showed significantly higher condition factor in spring is compared to autumn, but not to winter. Considering the relationship between total length and total body weight is suggested to simplify the management of the grow out phase of shrimp and estimation of the body weight and condition factor of individuals by means of total length could be easily managed.

Lead is one of the most toxic heavy metals for the human health. So researchers are always trying to remove of lead from the environment. Recently it was proved that probiotics by binding to heavy metals remove them from the environment. Hence, in the present study, the protective impact of Lactobacillus rhamnosus on hematological factors in rats infected with the lead with a potential to remove lead from the body is evaluated. 32 female rats (130 ± 20 g) were purchased from Pasteur Institute. The animals are randomly divided into 4 groups. A: control group, B: exposed to lead, C: Lactobacillus rhamnosus treatment, D: exposed to lead and Lactobacillus rhamnosus. After completion of the treatment period (8 weeks), blood parameters and the concentration of zinc protoporphyrine in the blood were measured. Levels of these factors in group D showed no significant change compared to group B. In group B, the number of white blood cells, lymphocytes, platelets and the concentration of zinc protoporphyrine showed a significant increase and the number of red blood cells, hematocrit percentage, hemoglobin concentration and its indices showed a significant decrease relative to the control group while changes of these factors in Group D compared to the control group had a lower level. So probably Lactobacillus rhamnosus was able to bind to lead and by its excretion from intestines, prevented from entry of excess lead into the blood. Therefore, the harmful effects of lead on blood factors have reduced.

In recent years the using of population controlling component for bacteria in the water of the fish is highly regarded. in this context, the selection of appropriate disinfectant with antibacterial property is very important. In this study zinc oxide nanoparticles were synthesized by sol-gel method and the minimum bactericidal concentration (MBC) of zinc oxide nanoparticles were evaluated to standard methods broth macrodilution serial dilutions, to determine the bacterial population in the aquarium environment includes two steps aquarium with goldfish and aquarium without fish. In the first step, concentrations of 0, 2 and 4 times of the MBC and in the second step, concentrations of 0, 2, 4 and 8 times of the MBC at special times added to aquarium water and antibacterial activity of zinc oxide nanoparticles were studied. MBC were measured 0. 35 ϻ g/ mL for bacterial populations of aquarium environment. The most process of obserd to reducing the total count of bacterial in concentrations of 4 times was observed after 5 days. The result of total count of bacterial aquarium environmental without fish, Indicate declines in 2 times of MBC until end of period while the concentration of 4 and 8 times of MBC, decreased the antibacterial activity of zinc oxide nanoparticles and total count of bacterial aquarium environment increased from 10 day. Therefore, due to the effects of zinc oxide nanoparticles acceptable antibacterial bacterial on the population of aquarium environment, it can be used as an antibacterial agent.

The study of fishes in aquatic ecosystems is important in many ways, including ecology, ethology, conservation and management of water resources, reserves and aquaculture, so the present study compared the geometric morphometrics of Barilius mesopotamicus populations in Bushehr basin. For this purpose, 140 fish specimens were sampled from Ahram, Zohreh, Kheirabad, Karzin, Shahpur and Darolmizan rivers. Specimens were transported to the laboratory after anesthetizing in 1% clove oil solution and fixing in 10% formalin. Pictures were taken from the left side of the specimens under similar condition and digitized using 15 landmarks placed on two-dimensional images using Tpsdig2 software. The data after Procrast analysis were analyzed with PCA, CVA multivariate statistical methods and cluster analysis. Geometric morphometric comparisons by CVA and cluster analyses showed significant differences in the studied populations and only Aharm and Karzin populations were were overlapping. Differences among the populations were due to differences in the body shape, head size and shape and body height.