39 research outputs found
The study of possible biotechniques and normative to production some species of Anostraca (Phallocryptus spinosa)
This project was carried out in order to determine the hatching conditions and laboratory culture methods of Fairy Shrimps (Phallocryptus spinosa). Physico- chemical factors and phytoplankton of natural habitat of this organism was investigated in Khasellou region around Azarshahr – East Azarbaijan province. The results showed that occurance and growth of fairy shrimps in their habitates were beginning from early Aprill and their survival was decreased with increasing temperature, precipitation and increasing the salinity of their culture medium. Then they disappeared. Their habitat phytoplankton contained 3 phylla and 10 genera, from which green algae enjoyed the greatest density in May. The pool salinity was around 20-17 g/l, when metanauplii was observed in early spring. In the pool containing and without fairy shrimps the oxygen concentration was high (9 mg/l) and low (2.9 mg/l), respectively. In 9 prawn ornamental fish genera, feeding with fairy shrimp showed a significant higher fecundity and hatching percentage compared to manual diets (cow liver, spinach). In all groups fed with fairy shrimp the duration of spawning time were reduced from 15 to 8-10 days and the color was enhanced. The means of cyst number per captured female also, cyst, decapsulated cyst and Naupilli diameters were mesured 142.9±19.0 cysts, 273.2±4.9µ, 242.4±3.8µ and 542.6±27.0 µ, respectively. The hatching rate was increased by reducing temperature and salinity of their culture mediums from 25 to 15 ◦C , and 28 to 18 g/l, respectively. The highest hatching was observed on 5th day at 15 ◦C and 18 g/l (5, 33 %). In addition, low but multiple hatching was observed. Therefore, water temperature and salinity affected hatching rate in this species. The hatching success of Phallocryptus spinosa cysts was better when collecting cysts together with dry sediments of their habitat without separation sensitive cysts. In addition to cold keeping and freezing, the hydration – dehydration method caused more diapause deactivation for hatching induction. The laboratory results revealed that the survival of fairy shrimps were highest at 15 ◦C (42%) and lowest at 25◦C (26%), respectively. Also, their life was inhibited in 30◦C. In different salinities, the mean survival rate were 26% (Salinity= 15 g/l) and 20% (Salinity= 25 g/l), respectively. The mean survival percentage of Phallocryptus spinosa cultured in natural habitat water (64.3%) was higher than aerated tap water (23, 3 %). Also, feeding with Nanochlorepsis caused higher survival rates. On the other hand, Beakers yeast caused higher mortality rates. Therefore, regarding to relatively high sensitivity of these species to physico– chemical and nutritional conditions of their culture medium, it is better to culture these species with expansion of their natural habitat in order to preserve their biodiversity, culture and increase stocking density with regard to environmental considerations
Effect of nutritive microalgae on growth and survival rates, nutrition value and reproduction performance of Artemia urmiana
Artemia is the most widespread live food used in the production of different stages in many aquaculture organisms. It is a non-selective filter feeding organism. Generally, microalgae are the most favorable feeds for Artemia, particularly when the algal species have suitable size, digestibility and nutrient values. This study was performed to compare the efficiency of three microalgae namely Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chlorella sp., Cheatocerus sp., Spirolina sp. and Isochrices sp. on the growth, survival and reproduction efficacy in Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the Walne and F/2 Guillard's culture mediums. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. Length growth of A. urmiana was measured by Motic SMZ- 168 stereomicroscope equipped by Motic MLC- 150c apparatus and related software in three-day intervals. To determine reproduction efficiency characteristics such as cysts and nauplious production, intervals between two successive reproductions, first reproduction time and the date of female Artemia were analyzed. Statistics analysis was performed by one-way variance (ANOVA) and Duncan test in SPSS 18 software. The results indicated a significant difference (p < 0.01) among three microalgae in terms of length growth, survival rates and reproduction characteristics in A.urmiana. On the other hand, there was a direct relationship between Artemia length growth and reproductive characteristics. In general, this study showed that survival rate, length growth and reproductive characteristics of A.urmiana fed by Dunaliella tertiolecta were significantly higher than A.urmiana fed by other microalgae.Therefore, it seems that Artemia culture in salt water with Dunaliella as natural flora is a suitable choice
A study on the parasites (protozoan and metazoan) of freshwater crayfish (Astacus leptodactylus) in the Aras reservoir
Aras reservoir freshwater crayfish is an important economic fisheries resource of West Azarbaijan, Iran. This study was concluded to evaluate the prevalence of parasitic infestation of Crayfish in this area during different seasons of 2012. Among 390 different sizes of Astacus leptodactylus which were examined, arrange of ectocommensals or ectosymbionts from a number of different phyla including 9 phylum and 11 class infested the different anatomic units of the surface and appendages such as gills, head , thorax, abdomen, walking legs, uropod, telson, antennae and antennulae of freshwater crayfish. Common groups such as peritrich ciliates, suctorian ciliates, free living nematodes, branchiobdellids, and Algae, copepods, rotifers and oligochaetes have also been observed in association with freshwater crayfish
Molecular barcoding of the Aras reservoir alga Microcystis aeruginosa (Kützing) Kützing 1846 by ITS-2 gene
Today, due to population increase and anthropogenic activities together with sewage and agricultural waste water entrance, aquatic ecosystems have been exposed to high pollutions. Phytoplankton is a group of water floating algae that have crucial roles in providing nutrients and oxygen for other organisms, nitrogen and CO_2 fixation. These organisms are considered as primary producers in aquatic ecosystems. They are found in various water habitats all over the world, affected by environmental variables such as pH, light and temperature and used for determination of water pollution degree and quality. Phytoplankton composition and density may be used as a complementary indicator of water trophy state. Phytoplankton communities indicate short and long term variations of aquatic systems. One of the most obvious problems in freshwater ecosystems is algal bloom or over growth of some blue- green algae which can decrease oxygen, and in some cases bring about toxin excretion and fish and human kills. In addition, many of bloom forming cyanobacteria produce secondary metabolites which can create sever poisoning in mammals including human. The genus Microcystis is a key bloom forming cyanobacteria in aquatic ecosystems. Populations of this genus form intense blooms in water bodies that has attracted more attentions in recent years. Various species of this alga have been distributed in stagnant and eutroph freshwater around the world. Microcystis has been defined by genetic criteria such as 16S rRNA molecular sequencing, but its classification in levels lower than genus is unclear and the presence of its classical morphospecies is doubtful. However, this genus creates sever blooms in eutrophic waters all over the world and many species produce toxins. Therefore, identification of its natural diversity in the levels lower than genus has high importance. However, several characteristics of Microcystis morphotypes which are classified a traditional species, actually are present and observed in different regions of the world. At present, they can be considered as morphospecies that belong to one genotype and have similar ecology. These traditional species with definite phenotypic and ecophysiological characteristics cannot be eliminated completely. Their identification is essential for ecological and ecotoxicological studies. Interistic transcribed separator (ITS) gene is a section of genome which is located between 16s rRNA and 23s genes. This gene has more heterogeneity than 16s rRNA; so it is used to identify many genera of cyanobacteria. The Aras reservoir located in the north-west of Iran plays important roles as fisheries, drinking and agricultural water supply and recreational activities in the region. The present thesis was undertaken to: analyze the Microcystis sp. populations by molecular methods such as ITS in Aras Reservoir. Samples for molecular analysis were collected from 10 sampling sites on 18 August 2013. Samples for molecular study of Microcystis were collected from two different depths (surface and 1 m depth) and transferred to laboratory without any treatments. Microscopic images of Microcystis were sent to professor Komárek and was confirmed
A study on the bacterial infections of freshwater crayfish (Astacus leptodactylus) in the Aras reservoir
Astacus leptodactylus is an important economical fisheries resource of Aras dam reservoir, in Iran. The infection of freshwater crayfish by gram negative and gram positive bacteria is often observed in natural and cultural environments which are considered as secondary disease agents or opportunities. This study was conducted to investigate infection conditions on 70 crayfish from the Aras reservoir regarding the bacterial agents by culturing from hemolymph in aseptic condition on Blood Agar, Trypton Soya Agar (TSA) and Cytophaga Agar The study was performed by biochemical tests. In this study Aeromonas hydrophila, Staphylococcus aureus, Micrococcus luteus and Flavobacterium johnsonaewere isolated and determined. According to the results of this study which was performed for first time on Aras reservoir freshwater crayfish, the percentage of crayfish which carried bacteria in hemolymph were variable ( 20-58.5%). Also, the gram negative bacteria particularly Aeromonas hydrophyla were dominant among the bacteria isolated from studied crayfishes
The comparative study of the streptococcinum, Hepar sulfur, Rosmarinus officinalis and erythromycin effects on cultured rainbow trout (Oncorhynchus mykiss) with experimental streptococcusis.
The comparative study of the streptococcinum, Hepar sulfur, Rosmarinus officinalis and erythromycin effects on cultured rainbow trout (Oncorhynchus mykiss) with experimental streptococcosis Homeopathy is one of alternative medicines that is very useful for soul and body diseases with accurate prescription. The goal of this study was “survey of the effects of homeopathic remedies. There is not any more research about homeopathy on aquatics in the world especially in Iran, thus Some research about the effects of homeopathy on aquatics is needed. In this study, the effects of streptococcinum, Hepar sulfure, Rosmarinus officinalis(homeopathic remedies) and erythromycin in cultured rainbow trout, with experimental streptococcosis, also the mortality, were compared. There was 6 treatment and 2 reviews in 300 liter tanks that each of treatment contained 40 juvenile rainbow trout with 25±5 gr arrange weight. Treatment 1: contained of erythromycin. Treatment 2: Streptococcinum C30. Treatment 3: Rosmarinus officinalis Q. Treatment 4: Hepar sulfur C30 . Treatment 5:(control treatment )without any injection and any therapy. Treatment 6: (positive control treatment) with injection but without any therapy. Daily estimation of the water temperature, oxygen, pH and salinity and some other chemical factors. Tretment 1 had significance with the other treatments. Survival percent in treatments and their analysis showed that treatment 4(Hep-s) had significance (p<0.05) with treatment 3(Ros-off) and its survival percent is more than the other homeopathic remedies. Erythromycin is chemical drug and has many side effects but Hep-s has not any side effect and is an natural remedy for Streptococcosis in homeopathy. Thus we offer the Hep-s to cure the streptococcosis but some research with disk diffusion test about the different doses of Hep-s is needed. Daily survey of clinical symptoms such as hemorrhages in the external organs, Under eyes, under skin, under fins and gills, hemorrhages and exophthalmos, were the most symptoms. Important pathological symptoms were: necrosis, hyperplasia and melanosis in branches, liver and kidneys, hemorrhages in heart, kidneys and in visceral tissues. According to the survival results, there was significant difference between the treatment 1 and the other treatments (p<0.05). Also there was significant difference between treatment 3, treatment 4 and treatment 2(p<0.05), this difference is due to the high dose(Q) of R.officinalis, while the two other homeopathic remedies were in a moderated dose (C30), 30× 100 diluted dose. Survival percent of treatment 4(Hep-s) was more than the other homeopathic remedies and was related to erythromycin. Erythromycin is chemical medicine and has many side effects, while Hepar sulfur has not any side effects if the prescription would be accurate. Hep-s is suggested with disk diffusion tests for relief the symptoms of streptococcosis
Determination of permitable distance between coldwater culture farms with common water supply in pirdanan river of West Azarbaijan
Regarding the increase in world population and decrease in fish stock, there is an urgent need to aquaculture practices. Coldwater fish culture is aiming at production and providing a part of protein needs of the country and a way reaching to self- sufficiency and preserve the water resources. Recently, multi- purpose use of water resources potential and especially the rivers of west Azarbaijan, for example, construction of fish farms at upstream of permanent rivers in order to make optimum use of the resources and the increase in employment has been considered . The waste water of these pools is usually discharged into the rivers. Regarding to increased production per unit area due to water resources and cold water fish culture restrictions to use regional facilities and fish farm construction, it is nessacery to determine limits between 2 farms. In this study with the goal of evaluation of the impacts of trout farm effluents on water quality parameters of Pirdanan River, the factors of water current, temperature, pH, EC, TDS, TSS, DO, BOD_5, NH_3, N-NO_2, N-NO_3, TP P-PO_4 according to standard methods were determined montly during 2014-2015 . Sampling sites were entrance, exit of Maroofi trout farm and the distances of 700, 1400, 2100 and 2800 m after the farm exit. Seasonal sampling of macro invertebrates from mentioned sites was conducted using stone leaching. The family and genus of macro invertebrates were identified using identification keys and abundance of macro invertebrate phylums for each site was determined. The results revealed that the values for water current, EC, TDS, TSS, N-NO_3 were significant. the values of water temperature, BOD5, TDS, TSS, N-NO^3- , N-NO^2-, NH_3, P-PO^4- , NH4+, N-NH3 were increased in site 2 compare to site 1 in all months and gradually in the river and its self- purification were decreased. In this study, 4 phylums, 4 classes, 7orders and 14 families of macroinvertbrates were identified from Pirdanan River. Ephemeroptera had the highest abundance in site 4; while Diptera had the highest abundance in site 2 (exit). Regarding that most of Diptera macro invertebrates were from Chironomidae, so it can be concluded that site 2 was the most pollutant site and sites 5 and 6 were more suitable condition. Therefore, considering the physic- chemical factors and macro inverteberates indices, 2100 m from entrance, (site 5) is recommended compliance with veterinary organization rules and other conditions of aquatic engineering, environmental and water operation standards
Stock assessment of freshwater crayfish (Astacus leptodactylus) in Aras reservoir
360 funnel traps were prepared as 30 in one row. They were bitted and located in different depths in sampling sites. Two rows each composed of 30 traps were located by stone, linking rope and boat with 50 m distance in sampling stations. The results showed that the average of total length of caught crayfish was 106.26±12.89 mm and their mean weight was 38.79 ± 15.54 gr. The largest crayfish had 171 mm length and 216 g weight. Also mean of total CPUE was 9.72±4.49 individuals in the study period. The evaluation by Schnabel approach indicated that fluctuation range of freshwater crayfish biomass with more than 120mm length was 131-313 with an average of 212.59 ±30.23 kilograms per ha. In this study freshwater crayfish biomass with more than 120mm length was 247 × 10^3 kilograms. The Maximum Sustainable Yield (MSY) was estimated 83 × 10^3 kilograms. In this study ّFecundity and biometry of crayfish (Astacus leptodactylus) was investigated during 2012-2013. The results showed that the average of total length of caught crayfish was 106.26±12.89 mm and their mean weight was 38.79 ± 15.54 gr. The largest crayfish had 171 mm length and 216 g weight. Mean number of ovarian and pleopodal eggs were estimated at 286 ± 82 and 246.31 ± 80.41 eggs (with 95% confidence limits), respectively. In this research, male to female ratio was obtained 1.21:1. The time of male moulting at 16°C was started from April and was ended in the late May, when the water temperature reached to 18° C. The second moulting of males and the first moulting of females was performed simultaneously in 18°C water temperature at September. Reproduction of freshwater crayfish was started from November and continued to May of the next year. Harvesting period was from May to late November