JOURNAL OF APPLIED ICHTHYOLOGICAL RESEARCH
Year:2018 | Volume:6 | Issue:2|Papers Count:9

A fish species prefer a particular habitat which provides its biological requirements, hence, understanding their habitat use and preferences are crucial for their effective management and protection. This research was accompanied to evaluate the habitat use and selection patterns of Paracobitis hicanica an endemic fish in Zarin Gol River. The river was sampled at 12 stations in spring 2016. A number of environmental variables, including water depth, width, elevation, velocity, substrate type and slope and the relative abundance of P. hicanica were recorded at each station. Based on the results, the habitat use by this species in Zarin Gol River was in altitudes of 250-810 meters above sea level, slopes of 9-26. 5 %, flow rate of 0. 4-1 m/s, widths of 1. 5-8. 5 m and depths of 0. 1-0. 6 m. The highest value of the standardized habitat selectivity indices for Western Crested loach in Zarin Gol River were related to the with elevation (490-570 m), slop (16. 5-19 %), velocity (0. 7-0. 8 m), width (4. 3-5. 7 m), depth (0. 1-0. 2 m) and bed rock substrate. This study provides the habitat use and environmental factors affecting on the distribution of P. hicanica in the Zarin Gol River.

In order to study fish biodiversity status in Lavij River and its relationship with environmental parameters, in January 2017, sampling was carried out in the river (about 20 km of river length) by electrofishing. 6 species of fish, including Luciobarbus capito، Paracobitis sp., Ponticola cyrius، Capoeta capoeta، Alburnoides eichwaldii and Squalius cephalus were identified. In the first and second stations, because of high altitude, and in stations of 13, 16 and 17 due to human manipulation, no fish sample was collected, while most samples were collected at stations 21 and 22. Biological indices showed the greatest value of Shannon Index in station 22 (H’ =1. 34) and the lowest value was obtained in stations 3, 4 and 5 (H’ =0) with the only recorded species, Luciobarbus capito. Station 3, 4 and 5 had the highest Simpson’ s dominance index. Regarding the abundance of species and specimens caught at stations, the highest species richness was detected at station 10. Spearman correlation between abundance and diversity indices with environmental parameters indicated that Shannon index had a significant correlation with nitrate, ammonium and Ec (p<0. 05). Based on the results of RDA, changes in environmental parameters can affect the abundance of different species, as the abundance of Alburnoides eichwaldii is mostly influenced by changes in temperature and ammonium level. Indices of Shannon, Pielou and, to some extent, Margalef revealed high changes in Lavij River and directly correlated with nitrate and ammonium levels. According to the sectional study, the present work probably introduces some information on the status of fishes in Lavij River, but not as much as completely. However, this can provide an overall view of fish’ s status in river to the ecologists

Salmo trutta fario is a vulnerable fish from Salmonid family in Iran and it exists in upstream areas of most Iranian rivers at southern Caspian Sea basin such as Hevigh, Shafarud, Tonekabon and Lar Rivers. The fish, samples were caught with electro-shocker, Cast-net and hook lines from winter to autumn 2010 and the aim was more information on the fish, feeding habit and its changes in different stations, seasons, fish body sizes and two sexes. Body weight was measured in studied fish specimens 1. 87-893. 9 (71. 40± 89. 80)g, total length 46-462 (161. 00± 64. 94)mm and age was 0+-7+ years old (3-aged specimens were dominant), too. The average index of intensity of food was measured, 344. 16± 327. 07, gastero-somatic index 7. 17± 5. 58 and relative length of gut 0. 89± 0. 10 and Kruskal-Wallis test showed significant statistical differences among rivers in these indexes and in fish, weight and length. The coefficient of gut vacuity was 0 (Zero), too. The fish has fed on 56 animal families belong to 20 orders in studied area consist of Gastropoda, Bivalvia, Hirudinea, Opistopora (Oligochaet vorms), Amphipoda, Isopoda, Coleoptera, Diptera, Ephemeroptera, Hemiptera, Hymenoptera, Lepidoptera, Megaloptera, Odonata, Orthoptera, Plecoptera, Trichoptera, Hydracarina, Myriapoda and Salmoniformes, that Dipteran, Coleopteran and Trichopteran insects with 12, 7 and 6 families are diversified, respectively in the alimentary tract of the fish. Current study showed little changes in food preference in different stations, seasons, fish ages and its sexuality, that Chironomidae, Simuliidae and Baetidae families were as preferred foods in all rivers, Heptagenidae in 3 rivers, Tipulidae in Shafarud river, too. Baetidae family was as preferred food in all seasons, Chironomidae in 3 seasons, Simuliidae and Hydropsychidae in 2 seasons and Tipulidae in one season, too. Chironomidae and Baetidae families were as preferred foods in all age-groups and Heptagenidae and Simuliidae in two age-groups, too. It was not observed any difference between males and females in food preference. In general, it can be said that the fish is a benthos-feeder and a euryphagous fish in studied Rivers.

One of the most popular problem against fishes and human is marine pollution. Cadmium is one of the most important contaminating elements which has a significant role in making marine pollution. In this study we have concerned the effect of sub-letal toxicity in ion of cadmium on amount of gene expression cytochrome P450 (the gene is senative to contamination) in liver and gill of CyprinusCarpio has done under laborator conditions. After a scrod CyprinusCarpio put next to the cadmium with density (0. 1 LC 50) sampling of their liver and gill are done on first, 7th and 14th day, in this tissues were collected the P450 gene expression level was determined by the method Realtime-PCR. The results show Cadmium P450 CYP1A gene expression in liver tissue increased significantly(p<0. 05) and P450 gene expression on the 1th and 14th day of exposure to Cadmium, increased significantly (p<0. 05). Relative expression this gene of exposure to Cadmium in the liver was significantly upper than the gill (p<0. 05) on the 14th day. Cadmium increased P450 CYP1A gene expression in this tissues.

Efficient food supply is the most important factors which must be considered to introduction of white fish (Rutilus frisii kutum) in an aquaculture system Therefore, in order to evaluate the effect of dietary protein and zinc on the growth performance and survival of this species, 360 pieces of white fish with an average weight of 0. 5 ± 0. 56 g were placed in twelve tanks (60 liters). Juvenile fish was fed with four different levels of protein diets (36 and 44%) and zinc (50 and 200 mg kg feed) for 83 days. The results showed that the growth and survival of Kutum significantly affected by different levels of protein and dietary zinc. The highest weight gain (0. 79 ± 0. 06), percent of weight gain (154. 88 ± 8. 7) and specific growth rate (1. 13 ± 0. 04) were observed in fish which fed with a diet containing 44 % protein and 0. 005% zinc, But the diet containing 36% protein and 0. 02 zinc 96. 67 ± 0. 00 percent) was revealed the highest survival rate. High With increasing levels of protein in the diet, whole-body protein contents are promoted. Overall, relativity the better response base on growth and body composition was observed in juvenile fish which with fed a diet containing 44% protein and 50 mg per kg zinc.

This study evaluated the effects of Valeriana officinalis root extract on on survival and biochemical factors of rainbow trout, Oncorhynchus mykiss during transportation. For this purpose, fish were distributed in 24 plastic bags, of which 12 contained the V. officinalis root extract (50 mg/l) (group B) and 12 had no herbal extract as control (group A). Transport lasted 16 h and every 4 h, 3 bags of each treatment were sampled. Survival, water quality parameters, plasma glucose and cortisol were studied. Results indicated that no significant differences in the pH, dissolved oxygen, ammonia levels and temperature were observed between treatments at all the assay periods (P > 0. 05). Serum glucose and cortisol levels were significantly (P < 0. 05) lower in group B over all the assay periods as compared to the control group. The survival rate (%) was significantly higher in group B compared to the control group (P < 0. 05). The present work revealed that the application of V. officinalis root extract will be effective in suppressing stress responses in O. mykiss and it can be recommended for rainbow trout transport.

Salinity is one of the important environmental factors affecting fish. To determine the effect of different aspects of salinity increase, it is important to determine the maximum salinity tolerance of fish. The salinity tolerance of Hamun mahi (Schizothorax zarudnyi) juveniles was evaluated in the laboratory by gradual and abrupt salinity increases. The mortality, behavior, gill histopathological alternations and chloride cells numbers were evaluated in the fish. In addition, fish were cultivated in 10 g/L for 20 days and at the end of the rearing period, their growth and blood factors were measured. LC50 value (lethal concentration) 24, 48, 72 and 96 hours were 11. 44, 10. 72, 10. 52 and 10. 52 g/L, respectively. The gradual transfer of fish to higher salinities resulted in an increase in the salinity tolerance (13g/L). The most observed changes in gill tissue included epithelial lifting (65%) and the smallest observed change was necrosis (14%). Also, the number of chloride cells increased by 16% after exposure to LC50 (96-h) concentration. There was no significant difference in growth rate, total protein, AST, ALP, and cortisol in fish reared in fresh and 10 g/L salt water, while glucose and triglyceride showed a significant difference. In general, the results of this study showed that it is possible to cultivate Hamun mahi in salt water (10 g/L), but due to the low growth of this fish during the cultivation period additional studies are needed to find a proper rearing condition.

The aim of the present study is to compare hematological and biochemical parameters of common carp (Cyprinus carpio) fed with separate and combined levels of multi-enzymes commercial feed. A total number of 96 common carp fingerlings weighing 13. 06± 2. 56 g and total length 9. 25± 1. 34 cm were distributed in six treatments including control (without multienzyme), 1000 and 1500 mg/kg Combo, 1000 and 1500 mg/kg Natuzyme and combined treatment of 1000 mg/kg Combo plus 1000 mg/kg Natuzyme into 12 tanks at a density of 8 fish per tank. At the end of a 8-week feeding trial, blood sampling was done to measure hematological parameters. Results showed that there were significant differences in final weight, body weight increase and feed conversion ratio among treatments (p<0. 05). Some treatments had an increase (p<0. 05) in RBC, contents of hematocrit and hemoglobin, WBS (except 1500 mg/kg Natuzyme) and lymphocyte number compared to the control. The highest number of lymphocyte was seen in 1000 mg/kg Natuzyme and 1500 mg/kg Combo which had significant difference with other treatments (p<0. 05). The maximum content of triglyceride was recorded in 1000 mg/kg Natuzyme that had significant difference with the control and combined treatment (p<0. 05). There were differences between levels of liver enzymes among treatments (p<0. 05). The highest content of amylase, protease and lipase were observed in 1500 mg/kg Combo and 1000 mg/kg Combo, respectively which showed significant difference with others (p<0. 05). According to the results, Natuzyme and Combo can be effective in the improvement of hematological and biochemical parameters of common carp fingerlings.

The aim of this survey was conduct to evaluated sorting efficiency on some growth indices of two weight group (245± 20. 33gr) and (490± 23. 58gr) (n=189) fry (Acipenser gueldenstaedtii). After environmental adaptation fish divided in three group (Small, Large and Mixed (none-grade)) by three replication, feed as appetite thrice a day in 8 weeks by ExS4mm commercial diet and measured some growth indices each two weeks. The results shown (p>0. 05) in initial biomass (BWI), Condition factor (CF) and Survival rate (SR %) between treatments. While in (p<0. 05) between treatments in Gain weight (GW), Gain weight percent (GW %), Growth Rate (GR), Special growth rate (SGR), food concentration ratio (FCR) and final biomass (BWF) and other indexes. Also, the mixed treatment had the best amount of FCR than others. Hence to the main goal of aquaculture sorting was improved the FCR and BWF index. Despite of increasing the BWF in Small treatment cause to lack of stress and manipulating cost (Acipenser gueldenstaedtii) sorting in these weights(fry size) were necessary.