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Notes: Lesions caused by plerocercoids of Triaenophorus nodulosus in the second intermediate hosts were studied in fish of an alpine lake, the Königssee. Four species (Arctic charr, Salvelinus alpinus; minnow, Phoxinus phoxinus; burbot, Lota lota: perch, Percafluviatilis) could be shown to be affected, whereas seven other fish species did not have macroscopical or histological signs of invasion. The capsules of T. nodulosus plerocercoids were usually located in liver tissue. Whereas only living parasites were found in charr and minnow, dead and destroyed plerocercoids could be demonstrated additionally in burbot and perch.The histological picture is characterized by capsules surrounded by connective tissue and by fresh or older migration routes in charr and minnow. Furthermore, larvae migrating through the biliary ductules were found regularly in charr. In burbot and perch, different stages of destruction of the parasitic larvae took place. The ability to reject the parasite by immunological reactions seems to depend on the species of host. Even if heavy changes in the liver tissue could be demonstrated, no negative influences on condition and growth of affected fish could be established.

Notes: The effect was examined of chronic exposure of young rainbow trout (Oncorhynchus mykiss Kendall) to a herbicide, N'-(3,4 dichlorophenyl)-N-methoxy-N-methylurea (Linuron).Three groups of fish were exposed to concentrations of Linuron of 30 ng/ml, 120 ng/ml and 240 ng/ml. The control grou was kept under identical conditions except that no Linuron was added to the aquarium water. At the end of the experiment blood was drawn by cardiac puncture. The isolated leukocytes were incubated over 2 hours with fluorescent plastic beads at either 4°C or 20°C. As a functional parameter, the percentage of cells that had taken up more than one particle was evaluated by flowcytometry. At a concentration of Linuron of 30 ng/ml the phagocytotic activity was lowest both at 4°C and at 20°C. With increasing herbicide concentration the percentage of phagocytic cells increased again.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméActivité phagocytaire comme test des effects de Linuron, un herbicide, sur la truite arc-en-ciel pendant une exposition chroniqueL'effet de l'exposition chronique á l'herbicide N'-(3,4 dichlorphenyl)-N-methoxy-N-methyluéte (Linuron), a été examiné chez des truites arc-en-ciel (Oncorhynchus mykiss, Kendall) jeunes. Trois groupes de poissons ont iti soumis sà des concentrations de Linuron de 30 ng/ml, 120 ng/d et 240 ng/ml endant 35 jours. Le groupe contrde a été soumis aux mêmes conditions, en omettant le Linuron dans l'eau de l'aquarium. A la fin de l'expérience, le sang a été recueilli par ponction cardiaque. Les leucocytes isolés ont été incubés pendant deux heures avec des billes de plastique fluorescentes sà 4° ou sà 20°C. Le pourcentage de cellules ayant phagocyté plus d'un particule (paramètre fonctionnel), a été calculé par cytométrie de flux. A une concentration de Linuron de 30 ng/ml, l'activité phagocytaire était la plus basse non seulement sà 4°C mais encore sà 20°C. Le pourcentage de cellules phagocytaires augmentait aux concentrations de l'herbicide plus élevées.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungPhagozytoseaktivitát als ein in vitro-Test für die chronischen Wirkungen von Linuron auf Regenbogen forellenEs wurde der Effekt einer chronischen Behandlung mit einem Herbizid (N'-(3,4 dichlorphenyl)-N-methoxy-N-methylharnstoff, Linuron) auf junge Regenbogenforellen (Oncorhynchus mykiss, Kendall) untersucht. Drei Fischgruppen wurden über 35 Tage Linuronkonzenuatioden von 30 ng/ml, 120 ng/ml oder 240 ng/ml im Hälterwasser ausgesetzt. Die Kontrollgrupe wurde unter gleichen Bedingungen ohne Herbizidzugabe gehältert. Am Versuchsende wurde dn Fischen mittels Herzpunktion Blut enmommen. Die aus diesem Blut isolierten Leukozyten wurden für 2 h zusammen mit fluoreszierenden Partikeln entweder bei 4°C oder 20°C inkubiert. Als funktioneller Parameter wurde der Prozentsatz der Zellen die mehr als ein Partikel phagocytiert hatten mittels Durchfluißcytometrie ermittelt. Es zeigte sich, daß bei 30 ng Linuron pro ml Wasser sowohl bei 4°C als auch bei 20°C die geringste Phagocytose-rate meßbar war. Mit steigender Herbizidkonzentration nahm dann die Phagocytose wieder zu.

Notes: Abstract. To evaluate the toxic effects of sublethal concentrations of the fungicide triphenyltinacetate (TPTAc), a prolonged toxicity study was made on rainbow trout (Oncorhynchus mykiss). Fish were exposed to TPTAc concentrations ranging from 1 to 6 μg TPTAc/L for 28 and 18 days, respectively, using a flow-through exposure system. Hematological findings included an increase of the total number of erythrocytes and an elevated incidence of erythrocyte degradation stages at 4 μg TPTAc/L and higher. The hemoglobin content and the packed-cell volume increased as well at 4 and 1 μg TPTAc/L. Whereas the total number of leucocytes increased in fish exposed to 1 μg TPTAc/L, the number of leucocytes tended to decrease at higher concentrations. The percentage of lymphocytes within the differential blood cell count decreased. The histopathological examination of TPTAc-exposed fish showed a dose-related lymphocytic depletion of the spleen, accompanied by a proliferation of reticuloendothelial cells and an increased erythrophagia even at the lowest TPTAc concentration. In severe cases, cell necrosis was evident. In liver tissue, a depletion of the glycogen deposits within the hepatocytes could be detected in fish exposed to 4 and 6 μg TPTAc/L. The analysis of the phenyltin compounds within various organs of fish by HRGC-FPD revealed remarkable concentrations of triphenyltin of up to 16.1 μg/g with the following order of residue levels: liver 〉 kidney 〉 spleen 〉 gills 〉 muscle. Di- and monophenyltin were found only in traces of 1–109 ng/g in these organs. The present study indicates that TPTAc negatively affects rainbow trout in a concentration range that might be present in aquatic environments.

Notes: Abstract To evaluate the toxic effects of sublethal concentrations of the fungicide triphenyltinacetate (TPTAc), a prolonged toxicity study was made on rainbow trout (Oncorhynchus mykiss). Fish were exposed to TPTAc concentrations ranging from 1 to 6 μg TPTAc/L for 28 and 18 days, respectively, using a flow-through exposure system. Hematological findings included an increase of the total number of erythrocytes and an elevated incidence of erythrocyte degradation stages at 4 μg TPTAc/L and higher. The hemoglobin content and the packed-cell volume increased as well at 4 and 1 μg TPTAc/L. Whereas the total number of leucocytes increased in fish exposed to 1 μg TPTAc/L, the number of leucocytes tended to decrease at higher concentrations. The percentage of lymphocytes within the differential blood cell count decreased. The histopathological examination of TPTAc-exposed fish showed a dose-related lymphocytic depletion of the spleen, accompanied by a proliferation of reticuloendothelial cells and an increased erythrophagia even at the lowest TPTAc concentration. In severe cases, cell necrosis was evident. In liver tissue, a depletion of the glycogen deposits within the hepatocytes could be detected in fish exposed to 4 and 6 μg TPTAc/L. The analysis of the phenyltin compounds within various organs of fish by HRGC-FPD revealed remarkable concentrations of triphenyltin of up to 16.1 μg/g with the following order of residue levels: liver 〉 kidney 〉 spleen 〉 gills 〉 muscle. Di- and monophenyltin were found only in traces of 1–109 ng/g in these organs. The present study indicates that TPTAc negatively affects rainbow trout in a concentration range that might be present in aquatic environments.

Notes: The wall of the asymmetrical saclike lungs of the fishes Polypterus and Erpetoichthys consists of several functionally different tissue layers. Their lumen is lined by a surface epithelium composed of (1) highly attenuated cells, termed pneumocytes I; (2) pneumocytes II with lamellar bodies, presumably indicating surfactant production; (3) mucous cells; and (4) ciliated cells. Underlying the pneumocytes I is a dense capillary net. The thin continuous endothelium of this net, together with the pneumocytes I, constitute the very thin blood-air barrier. The basement membrane of epithelium and endothelium fuse in the area of the blood-air barrier (thickness 210 m̈m). Secretory and ciliary cells form longitudinal rows in the epithelium. Below the zone with a gas-exchanging tissue, a layer of connective tissue containing collagen and special elastic fibers occurs. The blood vessels that give rise to or drain the superficial capillary plexus are located in this connective tissue. The outermost layer of the lung consists of muscle cells, a narrow inner zone with smooth muscle cells, and an outer, broader zone with cross-striated muscle cells. The lung is innervated by myelinated and nonmyelinated nerve fibers. The morphology of the gas-exchange tissue in the lungs of these primitive bony fish is fundamentally very similar to that of the lungs of tetrapod vertebrates. The morphologic observations are in close agreement with physiologic data, disclosing well-developed respiratory capacities. Structural simplicity can be regarded as a model from which the lungs of the higher vertebrates derived. In addition to respiratory function, the lungs seem also to have hydrostatic tasks.