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In this study we describe the anti-Trichodina effects of teflubenzuron (TFB) for Oreochromis niloticus and for Piaractus mesopotamicus. We also evaluated the acute toxicity, for both species, by using TFB in the concentrations of 700.0, 800.0, 900.0 and 1000.0 mg L(-1) and a control, without the drug. To assess the efficacy of TFB against Trichodina spp., we used the concentrations of 30.0 or 50.0 mg L(-1) for one hour exposure in tilapia, and the concentration of 30.0, 50.0 and 80.0 mg L(-1) for one hour and 50 mg L(-1) for two hours exposures in pacu. Teflubenzuron did not present significant toxicity in either species, with LC50;48h > 1000.0 mg L(-1). The drug effectiveness was observed against four identified Trichodina species: T. magna, T. heterodentata, T. compacta and T. centrostrigeata, with 87.9% parasite reduction with one hour exposure to 50.0 mg L(-1) TFB on O. niloticus and 96.1% with two hours exposure to 50.0 mg L(-1) TFB on P. mesopotamicus. Teflubenzuron is a drug with potential to be used in Brazilian aquaculture; it attends to important requirements, such as low toxicity and high efficacy in controlling Trichodina spp. infection in O. niloticus and P. mesopotamicus., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This study evaluated the haematological response of curimbas Prochilodus lineatus, naturally infected with Neoechinorhynchus curemai (Acanthocephala: Neoechinorhynchidae). Thirty-seven fish were captured in October 2010 from the Mogi Guaçu River, Porto Ferreira, SP, Brazil. Infected fish presented increased mean corpuscular volume of erythrocytes, and lower thrombocyte and higher monocyte counts than uninfected fish., (© 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.)

This work evaluated the acute inflammatory response induced by injections of 0.5 mL saline solution (control), 500 microg carrageenin and 0.5 mL thioglycollate 3% in the swim bladder of juvenile tambacu hybrid. Fish were distributed in three treatments, three replications and acclimated for a period of 10 days before assay. The cell characterization from the inflammatory exudate was performed in Giemsa and PAS stained smears. Carrageenin, injected in fish, showed an increase on the total number of cells in the inflammatory exudate when compared to saline and thioglycollate injected. Whereas, for carrageenin-injected fish, the percentage of thrombocyte was higher than thioglycollate. On the other hand, granulocyte percentage in thioglycollate-injected fish was higher than the ones injected using carrageenin. Carrageenin provoked the highest migration of macrophage to the inflammatory site. The PAS method confirmed the presence of three types of granulocytes: eosinophilic granular cell (EGC) type 1 with the characteristics of a special granulocytic cell commonly found in the circulating blood; EGC type 2 shorter than the last one and neutrophil. This study contributes to a better understanding of the inflammatory response and infectious processes in native fish.

The present work describes myxozoans found in Cyphocharax nagelli (Characiformes: Curimatinae) commonly called "sagüiru" collected from Rio do Peixe Reservoir, São José do Rio Pardo, São Paulo, Brazil. From a total of 38 examined fish, 24 were infected with Henneguya garavelli n. sp. (63% prevalence) and two with Myxobolus peculiaris n. sp. (5% prevalence) in the gills. Spores were studied by staining and fresh spores were observed by differential interference contrast optics. Henneguya garavelli n. sp. differs from Henneguya iheringi, Henneguya occulta, Henneguya cesarpintoi, Henneguya santae, Henneguya pisciforme, Henneguya amazonica, Henneguya striolata, Henneguya leporinicola and Henneguya chydadea in spore length and from Henneguya travassosi, Henneguya adherens, Henneguya malabarica, Henneguya piaractus and also Henneguya chydadea in polar capsule length and tail length. Myxobolus peculiaris n. sp. was very different when compared to other species of Myxobolus in its morphology and the biggest size of spore body. The authors present tables with comparative measurements of Brazilian myxozoan parasites.

This work evaluated parasitic infections by Neoechinorhynchus curemai (Acanthocephala: Neoechinorhynchidae) in Prochilodus lineatus captured between August 2000 and August 2001 in the Paraná River, Presidente Epitácio, São Paulo, Brazil. Of 87 fishes examined, 59 were infected (25 males and 34 females). High mean intensities occurred in August 2000 (45.2, range 2-204), September 2000 (28.5, range 11-73), October 2000 (59.3, range 2-250) and February 2001 (27.3, range 3-73). There was no relationship of rainfall with mean intensity and prevalence. Males were more parasitized (P<0.05) than females. This work contributes to the knowledge of helminth parasites of fish from a little studied region of the Paraná River, showing diversity in their fauna when compared to other places in the same river.

This work describes the presence of Contracaecum sp. larvae (Nematoda: Anisakidae) found in food fish of economic importance captured in occidental marshlands in the State of Maranhão, Brazil. Hoplias malabaricus (Erythrinidae) and Hoplerythrinus unitaeniatus (Erythrinidae), commonly called "traíra" and "jejú", respectively, were examined. All H. malabaricus were infected with a mean intensity of 24.6+/-38.3 (1-137 parasites per host) while eighty percent of H. unitaeniatus showed a mean intensity of 10.4+/-9.2 (2-31) parasites. Nematodes were most similar to larvae of a type 2 described by Moravec, Kohn and Fernandes [Moravec, F., Kohn, A., Fernandes, B.M.M., 1993. Nematode parasites of fishes of the Parana River, Brazil. Part 2. Seuratoidea, Ascaridoidea, Habronematoidea and Acuarioidea. Folia Parasitol. 40, 115-134], but differed in having a longer intestinal caecum and greater caecum/ventricular appendix ratio. Larval measurements and a description of their Brazilian fish hosts are presented.

The present work, studied the effect of 0, 1,000, 1,500 and 2,000 mg of garlic powder/kg dry ration for Piaractus mesopotamicus (Osteichthyes: Characidae), weighting 73.6 +/- 39.4 g and measuring 15.0 +/- 2.7 cm, fed for a period of 15, 30 and 45 days. Fifteen days after treatment with 1,000 and 2,000 mg of garlic/kg dry ration, significant reduction of Anacanthorus penilabiatus (Monogenea: Dactylogyridae) in the gills was related. Nevertheless, the addition of garlic to the ration caused significant increase in the erythrocyte number and in the thrombocyte percentage in the circulating blood. However, a decrease in the lymphocyte percentage was also observed. After 45 days, fish fed with garlic showed significant increase in the erythrocyte number, leucocyte, haemoglobin rate, hematocrit and thrombocyte.

The present work studied the prevalence and histopathology of Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala; Neoechinorhynchidae) from curimbatá, Prochilodus lineatus Valenciennes, 1836. Eighteen fishes with averages of 46.7 +/- 1.1 cm length and 1,674.8 +/- 75.6 g weight were collected with net, bimonthly from December 1995 thru December 1996 in the hydroelectric power station of Volta Grande Reservoir (Cemig), Minas Gerais, Brazil. From analysed fishes, 15 were infected with acanthocephalans in the intestine (prevalence 83.3%). The greatest mean intensity occurred in August 1996 with 66.5 (16 to 208) parasites. Histopathological analysis showed complete desquamation of the intestinal epithelium with severe hyperplasia and hypertrofia of the goblet cells. Severe inflammatory reaction at the submucosa, displacement of their sheaf, associated with oedema and mononuclear and eosinophilic infiltration were observed.