Histology of the inflammatory response of carp (Cyprinus carpio L.) to various stimuli

The present investigation was carried out to study the inflammatory response of carp (Cyprinus carpio L. ) to various stimuli. The stimuli were; surgical wound, talcum powder, Freund's complete adjuvant (FCA), a bacterium Aeromonas hydrophila, and spores of fungus Aphanomyces invaderis. Following exposure to these stimuli, fish were sacrificed over a period of time, and sequential tissue samples were processed for histopathological examinations. The surgical wounds at 27°C, re-epithelialized at 4 hours. Macrophage infiltration began at 2 hours, and myophagia at 6 hours. Fibroplasia and muscle regeneration were initiated at 2 days. After 16 days epidermis was normal and dermis was completely linked. The wounded area restored its main components by 16 to 24 days after wounding. Injection of talcum powder at 26.5°C, and FCA at 24°C, produced chronic granulomatousin flammatory reaction. The following events started in both experiments at the same time; myophagia at 6 hours, macrophages had changed into epithelioid cells, active fibroplasia and muscle regeneration at 3 days. Regenerated muscles filled the defects by 14 to 28 days post-injection (p. i. ). Langhans and foreign body giant cells, were observed after 3 days in talc and 4 days in FCA experiment. New capillaries formed at 3 days in talc and 2 days in FCA study. At the end of the experiments (42 days) the encapsulation of the irritants was very advanced, and the granulomata were entirely surrounded by normal muscle tissue. Inoculation of the Aeromonas hydrophila at 27.5°C, provoked a lethal acute inflammatory response within 48 hours. The surviving fish showed well developed capacity for dealing with bacteria. An ulcerative wound developed by 48 hours in the surviving fish. Polymorphonuclear cells (PMNs) were observed at 1 hour p.i . and remained up to 7 days. PMNs were one of the dominant inflammatory cells and participated in myophagia and micro-abscess formation. The acute inflammation then developed into chronic inflammation characterised by fibroplasia which was active at 5 days. Process of wound healing began and developed by 5-10 days and was completed by scar formation at 28 days. A chronic inflammatory response occurred after inoculation of spores of the fungus Aphanomyces invaderis at 27°C. Limited growth of the fungus in tissue occurred in the early stages p. i. but was then halted by fish's defence mechanisms. Macrophages had changed into epithelioid cells at 3 days p. i. Presence of Langhans, foreign body and intermediate giant cells, muscle regeneration, fibroplasia, and vascularization also started at 3 days. Developing granulomata formed by 10 days, and fully matured granulomata were observed by 18 days

Histopathology of mortality in cultured rainbow trout fry in some coldwater hatcheries and fish farms of Iran

Causes of the mortality of cultured rainbow trout fry in coldwater hatcheries and fish farms in Iran were investigated. Some 104 tissue specimens of liver, kidney, spleen, pancreas, intestine, and gill from 59 diseased fries from Mazandaran, Fars, Markazy and Kohgiloyely Boyerahmad provinces were collected for histopathological studies. Tissues were immediately fixed in 10% buffered formalin for at least 24 hours. The fixed tissues were processed in an automatic tissue processor using standard procedure. After processing, tissues were embedded into wax and 5 micron sections were prepared using a rotary microtome. The sections were stained using II & E staining method, and examined under compound microscope. The affected fries were dark in color, and showed exophthalmia, ascitis, erratic swimming, faecal casts in the anal area and lethargy. They also gathered near the outlet of the ponds. Microscopic examination of the tissues revealed histopathologic changes including congestion, inflammation of the basal membrane of secondary lamellae, hyperplasia, and fusion of secondary lamellae and clubbing in some cases in the gill. Congestion of blood vessels, degeneration of kidney cells, necrosis of hematopoitic tissue and tubules, increase of melanin pigments and infiltration of inflammatory cells were observed in kidney. In liver congestion of blood vessels, increase of fat in hepatocytes, congestion and dilation of sinusoids with increased monocytes, increase in melano-macrophage number, vacuolation of hepatocyctes and focal necrosis were seen. Bile duct neoplasia (cholangioma) was also present in some cases. Spleen showed congestion, hemosidrosis, increase in melano-macrophage centers and necrosis in some cases. The pancreas tissue showed congestion, degeneration and necrosis of ashlar cells and islets of Langerhans. Congestion of sub-mucusa layer, fusion of mucosa layer, necrosis and detaching of the mucoid columnar epithelium were observed in the intestine tissue. The clinical and histo-pathological examination results suggested that the causative agent of the fry disease is likely to be a virus with the signs similar to UN disease

In vitro studies on growth and reproduction of artemia in Incheh Lake

In this study some cysts of Artemia were collected from Incheh lake in Golestan province and then were incubated to obtain nauplii. These hatched nauplii were fed by Chlorella sp., and synechococcus sp., in three different treatments and three replicates with densities of 20, 40 and 60 specimen/lit and were reared up to adult stage. The period of rearing for above mentioned densities of two different algae were 15, 17 and 20 days; and in 16, 19 and, 23 days respectively. The average fecundity and mean length of Artemia fed on Chlorella sp. were 83.E 69.8 and 34.5 cysts/individual and 104, 10.1, and 9.1mm length; and for the Artemia fed on Synechococcus sp. were 54.1, 36.8 and 19.3, cysts per individual and 10.0, 9.0 and 8.8mm length, respectively. There were significant difference in growth rate and fecundity among the traetments of each group of Artemia (P<0.05)

UV-B impacts on morphology and retina of Oncorhynchus mykiss larvae

The harmful effects of ultraviolet radiation on aquatic animals, due to ozone layer reduction, have been long studied in recent years. Exposure of Rainbow Trout larvae (Oncorhynchus mykiss) to Ultraviolet-B radiation (UV-B) at different doses (68.75 µw/cm^2 and 94.83 µw/cm^2 as the minimum and maximum dose of UV-B in natural environment respectively) for 15 minutes once a day in dark condition in comparison to control group (without any solar or UV) showed a wide variety of body abnormalities and eye damages. Body curvature, yolk sac edema, fin blistering, dwarfism, eye and head abnormalities as morphological malformations were revealed during the experiment, none of the malformations were observed in control group. Histopathological changes in retina such as irregular and discontinues pigmented epithelium, necrosis of photoreceptors and degeneration of nucleus layers confirmed the destructive effects of UV-B radiation in the eyes of Rainbow Trout. Such changes in larvae can be valid as bio-indicator for pollution and UV radiation and also introduce fishes as model for toxicological studies

Study of pathological effects of an organic germicide bathing on rainbow trout

The aim of this study was evaluation an organic germicide (Aquagerm) histological affects on Rainbow trout (Oncorhynchus mykiss) vital tissues. This new disinfectant is an aquatic antiseptic and mixed-oxidant disinfectant which is produced for the first time in Iran. This new product mechanism is based on oxidant properties of pro-sulphate which attack crucial structures of pathogens. In this study, forty healthy fish were selected and divided into two groups as control and treatment. The treatment group was treated with 1/2000 concentration of organic germicide for 45 min (according to the manufacturing protocols). At 4, 8, 12, 24, 48 and 96 h after bath challenge, 5 specimens were collected from treatment and one from control group. Gill, brain, kidney, and liver of all fish were sampled. Some histological damages such as edema and detachment of basic layer in secondary gill filaments were observed in gill microscopy results. The most important histological changes observed in the brain were congestion of some blood vessels. Furthermore, some evidences of increased melano-macrophage, glomerular shrinkage, and dilatation in Bowman capsules were recorded whereas no any damages were observed in liver. All histological changes removed after 48-96 h. It could be concluded that, all pathological observations in this study were just a natural response of fish body after exposing to the new disinfectant, and they were not recorded any damages like those which happen against hazardous chemicals. It seems that there is no risk associated with the consumption of this disinfectant for the fish tissues

Isolation and identification of Flavobacterium columnaris like organisms from grass carp (Ctenopharyngodon idella) and assessment of its histopathological effects in Khouzestan Province, Southern Iran

Following a mortality of up to 40% of cultured Grass Carp (Ctenopharyngodon idella) in fish farms of Khouzestan province when water temperature was up to 20°C, samples were taken and examined for etiological clues. We observed that fish gills were coated with a gray-white mucus layer, fin was eroded and wounds were present in peduncle of the affected samples. Bacteriological studies on the samples of gills and eroded and wounded peduncle skin using Cytophaga selective medium, resulted in isolation of filamentous gram negative bacteria chemically similar to Flavobacterium columnaris. Histological observations showed the affected fish carrying symptoms including congestion, hemorrhagia, edema in base membrane, hyperplasia of chondrocyte and secondary lamellae cells, fusion of lamellae, necrosis and peeling of secondary lamellae and also presence of filamentous bacteria in gill tissue sections. Necrosis of skin layers and expansion of ulcer to underlying muscles, degeneration of muscle cells and necrosis of muscle bundles were seen in peduncle muscles. We did not find this bacterium in internal organs. We conclude that the isolation of the bacterium and observation of histo-pathological changes suggest the organisms may be considered as a primary or secondary factor in occurrence of the disease

Short communication: Effect of oral consumption of Aloe vera gel on intestinal microflora and liver tissue of rainbow trout

Rainbow trout as an important breeding fish has a special place in the food basket of human societies. Statistical survey shows that in the period between the years of 1995 to 2011, the number of trout breeding farms and the amount of salmon production in Iran have increased respectively by more than 23 and 70 times. ... In recent years, several studies have been conducted on adding the medicinal plants to the feed and using their beneficial effects in aquaculture, while the diversity of medicinal plants and their treatment effects require extensive research. A. vera plant belongs to Liliaceae family which in traditional medicine, various effects such as rejuvenating, antiinflammatory, antifungal and germicidal have been listed for it. Sixty percent of the dry matter of A. vera gel is polysaccharides and if they have prebiotic material specifications, they can affect intestinal bacteria populations. … The aim of this study is addition of A. vera gel in rainbow trout feed and investigate its effect on intestinal microbial flora population and liver tissues of fish

Stability Analysis of Behesht-Abad Water Conveyance Tunnel Inlet Portal Using Experimental, Limit Equilibrium and Numerical Methods

The Behesht-abad Water Conveyance Tunnel is one of the most important tunnels conveying water to central Iran plain having 60 km length and 6 m diameter. The tunnel portal intersects with important faults of the region which is nearby Ardal city. Therefore, the rock mass surrounding the tunnel portal faces instability problem. Initially, the joints characteristics of the rock mass surrounding the inlet portal were evaluated to find the dominant joint sets along with the characteristics required for stability analyses inputs. Also the deformation modulus and other engineering properties of the rock mass were assessed using the available drilled boreholes data. The extensive stability analyses were conducted using stereographic, empirical SMR, limit state equilibrium and 3-dimensional discontinuum numerical methods. Finally, the results of the analyses were compared together

Genetic characterization of Lactococcus garvieae isolated from farmed rainbow trout by random amplified polymorphic DNA-PCR in Iran

Lactococcosis is one of the main bacterial infections of fish around the world. Lactococcus garvieae has been a major cause of rainbow trout losses in freshwater farming. This study aimed to genotype and determine the variability of L. garvieae isolated from infected farmed rainbow trout in Iran by the RAPD-PCR method. Bacterial samples were collected from 12 farms located in the western part of Iran and suspected to carry Lactococcus infection. Two hundred bacterial cultures containing cocci shaped bacteria were cultured in Trypticase soy agar (TSA) and blood agar mediums. All bacterial cultures were tested by conventional microbiological and biochemical tests, and PCR assay to identify L. garvieae by 16S rDNA genes. The RAPD-PCR method was used to determine the genetic pattern of all isolates. The sample strain pattern of the isolates was analyzed in the NTSYS program. According to a similarity coefficient index of 70%, all L. garvieae isolates were separated into two groups with four RAPD profile types. The highest and the lowest genetic pairwise similarity among the isolates were 98% and 54%, respectively. The results of the present study revealed that RAPD-PCR is an applicable method to describe the genetic diversity of different strains of L. garvieae among farmed fish