Clinical And Pathological Investigation Of Psychrobacter Immobilis Infection In Rainbow Trour (Oncorhynchus Mykiss, Walbaum)

The pathogenicity of Psychrobacter immobilis, isolated from naturally infected rainbow trout Oncorhynchus mykiss, was investigated. In experimentally-infected trout, no mortality was recorded during 35 days but the following external and internal symptoms were observed. Externally, skin was darkened, gills were pale and swimming was abnormal. Internally, there were dilatations of the vascular structures on cross-sections of the liver; vascular congestion, inflammatory mononuclear cell infiltration and degeneration in the gills; interstitial inflammatory mononuclear cell infiltration and free bleeding in patches of the posterior kidney; vascular con- gestion and free bleeding in the spleen; degeneration, atrophy, polymorphonuclear leukocyte infiltration and liquefaction necrosis in muscle fibers; edema, inflammatory mononuclear cell infil- tration and basophilic degeneration among muscle fibers of the heart; and congestion in vascu- lar structures on cross-sections of the brain tissue. It is suggested that P. immobilis is an oppor- tunist pathogen that causes secondary infections

Hatchery And Growth Performance of Two Trout Pure Breeds, Salvelinus Alpinus And Salmo Trutta Fario, And Their Hybrid

An allelic cross between Salmo trutta fario and Salvelinus alpinus was carried out under con- trolled hatchery conditions. Survival to the eyed stage was significantly lower for the hybrid than for both purebreds. There were significant differences in survival in the eyed and yolk sac stages and from fertilization to the first feeding (p0.05). The hybrid did not display heterosis with respect to any hatchery property. During the first 45 days of nursing, there were significant differences between the purebreds and the hybrid in terms of weight gain, survival, feed conversion ratio and specific growth rate (p0.05). The hybrid was slightly heterotic (+1.69) with respect to survival how- ever no heterosis was observed in any other property to the first feeding stage

Effects of low molecular weight plasma inhibitors of rainbow trout (Oncorhynchus mykiss) on human erythrocyte carbonic anhydrase-II isozyme activity in vitro and rat erythrocytes in vivo

The effects of low molecular weight plasma inhibitors from rainbow trout (Oncorhynchus mykiss) (RT) were investigated on the carbonic anhydrase enzyme (CA) activities in in vitro human and in in vivo Sprague–Dawley rat erythrocytes. The RT blood was used as extracellular fluid (plasma) source and plasma inhibitors were obtained by dialysis of the plasma. For the in vitro study, human carbonic anhydrase-II (HCA-II) isozyme was obtained by Sepharose 4B-l-tyrosine-sulfanylamide affinity chromatography with an overall purification of about 646-fold. The enzyme (specific activity of 7750 EU/mg protein) was obtained with a yield of 71.1% and SDS-PAGE showed a single band. From in vitro studies, the I50 value for RT plasma inhibitors obtained was 0.37 mg/ml. From in vivo studies on rat erythrocytes, CA activity was significantly inhibited by the inhibitors from the extracellular fluid of RT for up to 3 h (p<0.05) following intraperitoneal administration

Kinetic Behaviour of Glucose 6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase in Different Tissues of Rainbow Trout (Oncorhynchus mykiss) Exposed to Non-Lethal Concentrations of Cadmium

The effects of cadmium (Cd) on the enzymatic activities of glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) were investigated in the gill, liver and kidney tissues of rainbow trout (Oncorhynchus mykiss). Three test groups of fish were subjected to increasing concentrations (1, 3 and 5 mg/l) of cadmium (Cd) in vivo, respectively. The G6PD and 6PGD activities in the gill, liver, and kidney tissues of each group of fish were measured on days 1, 3, 5 and 7. G6PD and 6PGD enzyme activities, measured in gill, liver and kidney homogenates, were stimulated by various concentrations (1, 3, and 5 mg/l) of cadmium. Although the dose-response pattern of G6PD enzyme activities in liver and kidney tissue was very similar, that in gill was different from both other tissues. The enzyme activity of G6PD enzyme was significantly stimulated after three days (Day 3) in liver and kidney tissues at a dose of 1 mg/l Cd (p p p p p p < 0.05) in liver and kidney tissues at the doses of 3 and 1 mg/l Cd. The stimulation effect of cadmium on the three tissues studied was also calculated; for both of the enzymes (G6PD and 6PGD), the enzyme activity levels were stimulated by approximately 60% and 38% in gills, 68% and 44% in liver, and 67% and 41% in kidneys, respectively, over the base-line enzyme activity of the control groups during the sevenday experimental period. These findings indicate that tissue G6PD and 6PGD enzymes function to protect against cadmium toxicity

The Effects of Different Sized Granules and Particle Composition on Growth of Rainbow Trout (Oncorhynchus mykiss)

Three feeding regimes were tested to determine their effects on growth, survival, and feed conversion in rainbow trout alevins for 60 days. In the first regime, the alevins were fed a starter feed consisting of 800 micron parti- cles for the first 15-day period. For the following 15-day period, the alevins were given a starter feed consisting of 1200 micron particles. For the final two 15-day periods, the alevins were given feeds consisting of 1500 micron and 2 mm particles, respectively. In the second regime, feed particles in the four periods were 1200 micron, 1500 micron, 2 mm, and 3 mm granules, respectively. In the third regime, feeds contained 1500 micron, 2 mm, 3 mm, and 4 mm granules. During the first two 15-day periods, no significant dif- ferences in growth parameters were detected (p>0.05). In the second two 15-day periods, there were significant differences in final live weight, growth, and feed conversion rates between groups (p0.05)

Effects of Chloramine-T And CuSO4 On Enzyme Activity Of Glucose 6-Phosphate Dehydrogenase From Rainbow Trout (Oncorhynchus Myskiss) Erythrocytes In Vitro An In Vivo

Traditional treatments of parasitic and bacterial diseases are based on chemotherapeutic com- pounds such as chloramine-T and CuSO4. Although many compounds are used in fish treat- ments, their undesirable effects are not known. In this study, glucose 6-phosphate dehydroge- nase (G6PD) was purified from rainbow trout (Oncorhynchus mykiss) erythrocytes by hemolysate preparation, ammonium sulfate precipitation and 2', 5'-ADP Sepharose 4B affinity gel chromatography in a single day. The enzyme, with a specific activity of 14.51 EU/mg protein, was purified 906.8-fold with a yield of 70.38%. To check the purity of the enzyme, SDS poly- acrylamide gel electrophoresis was performed, which showed a single band. The effects of chlo- ramine-T and copper sulfate (CuSO4) on the G6PD were investigated in vitro. Chloramine-T and CuSO4 had inhibitory effects on the enzyme. I50 values of the chemotherapeutic compounds were determined by plotting percent activity and Ki values, and types of inhibition were deter- mined for each compound by means of Lineweaver-Burk graphs. In vivo studies showed that G6PD in rainbow trout erythrocytes was significantly inhibited by CuSO4 in one hour but not inhibited by chloramine-T

Individual and combined ecotoxic effects of water-soluble polymers

Water-soluble polymers (WSPs) are a class of high-molecular-weight compounds which are widely used in several applications, including water treatment, food processing, and pharmaceuticals. Therefore, they pose a potential threat for water resources and aquatic ecosystems. We assessed the ecotoxicity of four WSPs—non-ionic polyacrylamide (PAM) and polyethylene glycol (PEG-200), anionic homopolymer of acrylic acid (P-AA), and cationic polyquaternium-6 (PQ-6)—as single compounds and in mixture. For this purpose in vitro and in vivo assays were used to record baseline toxicity, mutagenic potential, endocrine effects, and growth inhibition in the freshwater alga Raphidocelis subcapitata. Furthermore, the mixture toxicity of the two polymers P-AA and PQ-6 which showed effects in the algae tests was evaluated with the concentration addition (CA), independent action (IA), and generalized concentration addition (GCA) model and compared with experimental data. No toxic effects were observed among the polymers and their mixtures in the in vitro assays. On the contrary, in the growth inhibition test with R. subcapitata the cationic PQ-6 caused high inhibition while the anionic P-AA and its mixture with the cationic polymer caused low inhibition. The non-ionic polymers PEG-200 and PAM showed no effect in R. subcapitata in the tested concentration range up to 100 mg/L. The IA model represented the mixture effect of the combination experiment better than the CA and GCA models. The results indicate (1) that the toxic effects of anionic and cationic polymers are most likely due to interactions of the polymers with the surfaces of organisms or with nutrients in the water and (2) that the polymers elicit their effects through different mechanisms of action that do not interact with each other

Effect Of Photoperiod On Plasma Thyroxine Hormone Level Of Mirror Carp (Cyprinus Carpio) Raised At A Low Water Temperature In A Controlled Environment

The objective of this study was to examine the effects of various lighting regimes on the plasma thyroxin hormone (T4) level of mirror carp (Cyprinus carpio). The carp were kept at the low tem- perature of 9°C to eliminate any influence of water temperature on feed intake, growth, and the hormone level. Treatments were 8 h light:16 h dark, 12 h light:12 h dark, and 16 h light:8 h dark. Plasma thyroxin levels were measured every four weeks for 12 weeks. The levels were signifi- cantly higher (p<0.05) in the groups exposed to 8 or 12 h light than in the group exposed to 16 h. The T4 levels significantly dropped with time in all photoperiods