Experimental methemoglobinemia in rainbow trout

Abstract

Institute of IchthyologyIn the experimental way methemoglobinemia was caused to occur in rainbow trout, Salmo gairdneri Rich., 1836 by keeping the fishes for 11 weeks in Ca(N0 3 ) 2 and KN0 3 solutions, the N0 3 doses in which being 26.2 mg/1 and 30.6 mg/1, respectively.At the ·same time measurements of the hepatic tissue respiration rate, histopathologic studies of liver as well as examination of the peripheral blood and hematopoietic organs were carried out.Marked changes which eventually could be lethal were found out. INTRODUCTIONMore and more frequent reports on the deleterious effect of nitrates contained in drinkable water on the man's health (Schaefer, 1970and others)tumedour attention to a possible relation of the problem to fish. Thus an experiment on rainbow trout, Salmo gairdneri Rich., 1836 was planned and carried out; the results are presented herein;The whole experiment· was based on 50 mg/1 nitrate dose corresponding with 26.2 mg N0 3 /1 for Ca/N0 3 /2 •4H2 0 = 236.16 and 30.6 mg N0 3 /i forKN03 = 101.1. The · WHO -allowtld N0 3 dos� .in drinkable water is 50 mg/1 (Schaefer, 1970).The. following authors are responsible for the present report: E. Grabda, general principles and the histopathologic studies; T. Einszpom-Orecka, hematology; C. Fel:inska, the methemoglobin level determinations; R. Zbanyszek, the hepatic tissue respiration metabolism. 44Eugeniusz Grabda i wsp. METHODS60 two-years old individuals of rainbow trout measuring 18/20 -23/26 cm (L.c./L.t.) and weighing 73-155 g (only a few of them of weight below 90 g) taken from the same hatchery were subject to experiments.The experiments were carried out simultaneously in 3 tanks: two of 400 1 effective capacity each, the remaining one of 230 l. The fishes were divided into 3 groups of 20 individua ls per tank. Tank ,,A" ( 400 1) filled with clean tap water was a control. 50 mg/I of calcium nitrate c.p., Ca/N0 3 / 2 ·4H 2 0 and pure potassium nitrate, KN03 were added to water of tanks ,,B" ( 400 l) and ,,C" (230 1). respectively. The three tanks contained normal drinkable tap water. To ensure possibly equal nitrate concentrations the water was changed every 1-2 days (in exceptional cases every third -in the final stage of experiments) instead of applying the water flow. Usually such a change was accomplished after feeding. The fishes were fed on frozen cod supplemented, when necessary, with a granulated food normally used in the hatchery. The artificial food was given only exceptionally and could not influence the course of experiments. The water was constantly aerated with an electric aerator, the action being doubled in the smaller tank to compensate for losses resulting from a greater fish density there.Doses of 50 mg/1 pure salts were used, the fresh solution being prepared after each water change in the experimental tanks. To adapt the fish organisms the doses were gradually increased during the first three days.At the beginning of the experiment, water temperature was approximately 15°C, decreasing to 11 °C on completing. The oxygen ...

Nitrate toxicity toPenaeus monodon protozoea

“…Brownell (1980), reported 24 h LCs0 levels ranging from 18.8 to 38.3 g N O 3 1-1 for several species of marine fish, and ECs0 levels ranging from 2.6 to 4.5 g NO;-1-1. The only indication that rela- tively low concentrations of nitrate may be harmful to fish comes from Grabda et al (1974), who found that rainbow trout exposed to 22.0-26.4 mg N O f 1-1 displayed increased blood levels of ferrihaemoglobin, damage to the peripheral blood and haematopoietic centres, and liver damage. However, their data was not definitive since nitrite was not measured in the experiments, and these effects may have been caused by nitrite accumulation (Colt and Armstrong 1981).…”

Effects of physiological factors, stress, and disease on hematologic parameters of carp, with a particular reference to the leukocyte patterns. III. Changes in blood accompanying branchionecrosis and bothriocephalosis

“…Branchionecrosis A considerable reduction in the erythrocyte count and erythrocyte cytolysis were found to accompap.y the acute fonn of the disease. Cytolysis has been known as one of the effects of toxic agents (Waluga and Flis, 1971;Grabda et al, 1974;Schreckenbach and Spangenberg, -1978). Recent findings on adverse effects of ammonia as a direct branchionecrosis-causing factor seem to be corroborated by such morphological changes in erythrocytes.…”

“…On the one hand, hematologic assays allow to estimate the force of a disease-causing agent (Einszporn-Orecka and Wierzbicka;1974;Grabda et al, 1974); on the other, they can be very helpful in identifying the disease and in diagnosing conditions of unclear etiology (Lejman, 19 5 5;Spoljanskaja, 1966;Blaxhall and Daisley, 1973).…”

Photocatalytic reduction of nitrate in seawater using C/TiO2 nanoparticles

“…The most toxic effect of nitrate on aquatic environment is the eutrophication [6]. Moreover, the discharge of these nitrogenous compounds into the aquatic environment can also cause serious problems such as the transformation of oxygen-carrying pigments (e.g., hemocyanin and hemoglobin) to a form of methemoglobin which is incapable of carrying oxygen [7][8][9]. Conventional physicochemical and biological treatment processes for denitrification of wastewater including reverse osmosis, ion-exchange, adsorption, chemical coagulation and bacterial assimilation do not provide long-term solutions due to several limitations and drawbacks such as involvement of complicated procedures, tendency to generate concentrated wastes and high cost [10].…”