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Saccharomyces cerevisiae is rich in bioactive ingredients and nutrients such as essential amino acids, peptides, cell wall carbohydrates, nucleotides and B vitamins. Diets with this immunostimulant product may offer improves in growth performance and immune of farmed fish. This study evaluated the effects of a commercial immunostimulant based on S. cerevisiae on growth performance, hematology and immunity of Arapaima gigas subjected to handling stress after 30 days of supplementation (0, 4, 6 and 8 g kg−1). Diet with 6 and 8 g kg−1 of immunostimulant increased final biomass, final length, body weight gain, daily weight gain, daily feed intake, specific growth and decreased the cholesterol levels. After handling stress, supplemented fish with 4, 6 and 8 g kg−1 of immunostimulant had increase in glucose levels and decrease in globulin levels, while supplemented fish with 4 and 6 g kg−1 had decrease in cholesterol, and supplemented fish with 4 and 8 g kg−1 in globulin levels. Protein levels decreased in supplemented fish with 4 g kg−1, while hematocrit decreased in all treatments and lymphocytes number and burst respiratory of leukocytes decreased in supplemented fish with 8 g kg−1 and submitted to handling stress. For A. gigas, since 6 to 8 g kg−1 of immunostimulant has not negative impacts on the hematological and biochemical parameters, thus such concentrations may be used as a growth promoter in A. gigas. Made available in DSpace on 2020-12-09T09:10:57Z (GMT). No. of bitstreams: 1 CPAF-AP-2020-Growth-and-hematological-and-immunologica.pdf: 261909 bytes, checksum: d538d950672be57c8f92749a731c3c6e (MD5) Previous issue date: 2020

The present study evaluated the effects of dietary yeast supplementation on the growth and blood parameters of Arapaima gigas. Fish were fed with commercial feed supplemented with NuPro® at 0, 10, 40 and 80 g / kg for days and, did not exhibit any difference in growth. Blood was analyzed at the end of the feeding trial and after handling stress. A significant reduction in albumin and triglycerides levels was observed with increased supplementation of NuPro® in the diet of A. gigas. The interactive effect of diet and stress influenced plasma glucose levels, with a modulation at all levels of supplementation after stress, while in the control group the level was significantly high. NuPro® improved the innate immune response of A. gigas at all the tested concentrations, with a significantly higher levels number of thrombocytes, leukocytes, lymphocytes, monocytes, and neutrophils than the control group. There was also an increase in the number of thrombocytes after stress. As the inclusion of NuPro® in the diet improved the innate immune response at all the concentrations tested and effectively modulated plasma glucose levels, this product can be recommended as an immunostimulant for A. gigas fingerlings with the inclusion of 40 g/kg of feed. Made available in DSpace on 2020-12-09T09:08:44Z (GMT). No. of bitstreams: 1 CPAF-AP-2020-Innate-immune-response-of-pirarucu.pdf: 276238 bytes, checksum: 221944425940fbbc325ab8e961ff9479 (MD5) Previous issue date: 2020

This study compared the parasites fauna of Hyphessobrycon takasei and H. amapaensis from hydrographic basins in Amapá state, Brazil. Of the 42 H. takasei examined, 95.2% were parasitized by one or more species such as Dactylogyridae gen. sp., encysted metacercariae of digenean, adults and larvae of Procamallanus (Spirocamallanus) inopinatus and larvae of Camallanus sp. A total of 224 parasites were collected from H. takasei, and there was a dominance of nematode species and dispersion pattern aggregated of parasites. The species richness of parasites varied of 0 to 3 species, Brillouin index of 0-0.97 and evenness of 0-0.70. Of the 32 specimens of H. amapaensis examined, 28.1% were parasitized by Camallanus sp. larvae, which presented random dispersion pattern. For H. takasei, no correlation of host length with Brillouin diversity and species richness of parasites was found. The presence of these nematode species and metacercariae of digenean indicates that these fish may act as intermediate hosts. This is the first study to gather information about the parasite fauna of these endemic fish from the eastern Amazon, providing records that contribute new reports on occurrence of parasite species in new localities. This study on parasites of H. takasei and H. amapaensis may help prevent the introduction of parasites in other regions of the country, as well as in other countries due to aquarium fish. Since the ornamental fish exportation from the Brazil is largely dominated by wild Amazonian species, biosecurity export conditions should be require all exported fish to be inspected and certified to show no clinical signs of parasite and diseases. Lastly, this knowledge on the parasitic epidemiology may help improve the health and quality of these fish being exported from the Amazon region, reducing losses on all stages of this production chain. Made available in DSpace on 2019-07-27T00:52:37Z (GMT). No. of bitstreams: 1 CPAFAP2019ParasiticfaunaofHyphessobrycon.pdf: 1030381 bytes, checksum: 9a8e205223d54f3249187d70692a4429 (MD5) Previous issue date: 2019

The current study tested the efficacy of a dietary immunostimulant additive (Aquate Fish?®) on the growth performance, and on the physiological and immune responses of Arapaima gigas. Two trials were carried out: a feeding trial for 30 days with the experimental diets and a challenge trial for 7 days, in which fish were bacterial challenge (Aeromonas hydrophila) following by 60 s handling stress. During the feeding trial, fingerlings were fed diets supplemented with 0 (control), 6, 9 and 12 g Aquate Fish?®/kg diet. Dietary supplementation did not influence feed intake, feed conversion and condition factor, but increased the final biomass, number of erythrocytes, thrombocytes, leukocytes, lymphocytes, monocytes, hemoglobin, glucose, globulins and plasma triglycerides in fish fed at a concentration of 12 g/kg diet. After bacterial infection, mortality occurred only in fish fed control treatment, whereas respiratory burst of leukocytes, number of leukocytes and lymphocytes increased in fish that received 12 g of dietary supplementation. The results indicated that dietary supplementation with 12 g of Aquate Fish?® improved biomass and immunity performance of A. gigas fingerlings, without negatively affecting blood biochemical parameters. Made available in DSpace on 2019-09-10T00:56:00Z (GMT). No. of bitstreams: 1 CPAFAP2019Growthphysiologicalandimmune.pdf: 184829 bytes, checksum: d15cf60e4f16da2c64a7003e57d1da27 (MD5) Previous issue date: 2019

This study compared the structure and composition of the parasite communities in Callichthys callichthys and Megalechis thoracata of a tributary of the Amazon River system, northern Brazil. A total of 447 parasites was collected from 38 specimens of each host, and 44.7% and 36.8% of fish species respectively were found to be infected with 1 or more species of parasite. The similarity in parasite assemblages between hosts was high (61%) with both infected at similar levels by Genarchella genarchella, larvae of Eustrongylides sp., Rhabdochona sp. and plerocercoids of Proteocephalidae. However, the dominant parasites found in C. callichthys were metacercariae of Posthodiplostomum sp., which did not infect M. thoracata. In M. thoracata the dominant parasite was G. genarchella, and this host species was also infected by Gorytocephalus spectabilis which did not infect C. callichthys. The parasite communities were dominated by endoparasites, and species richness of parasites, Shannon diversity index and evenness were similar for both hosts. The results indicate that these fish species are intermediate hosts of the endohelminths found. Finally, the variation in the parasite community between sympatric hosts occurred probably due to the hosts? distribution in the environment and the diet of each host species. Made available in DSpace on 2018-06-15T00:37:07Z (GMT). No. of bitstreams: 1 CPAFAP2018Diversityandsimilarityoftheparasites.pdf: 2091749 bytes, checksum: 6780109b2d842659f1436dd5b3259704 (MD5) Previous issue date: 2018-06-14

This study aimed to determine the lethal concentration and the structural and ultra-structural effects caused by the formalin exposure on juveniles of Arapaima gigas. Ninety fish (60.1± 2.5g and 20.2±0.9cm) were exposed to 0, 22, 44, 66, 88 and 110mg L-1 in order to determine the lethal concentration (LC50-96h) that was 36.4mg L-1 of formalin. Sublethal effects were evaluated using histopathological analysis on the gills and assessment of behavioral alterations and clinical signs. The LC50 of formalin for 24, 48 and 72h was 88.3, 64.7 and 56.8mg L-1 respectively. Clinical signs and behavioral changes were found: erratic swimming, lethargy, crowding on the water surface, loss of hydrodynamic equilibrium, spasms and agonistic confrontation, which were observed only at 88 and 110mg L-1. The histological alteration index (HAI) showed that 66, 88 and 100mg L-1 presented significant difference (p

Este estudo avaliou a fauna de metazoários parasitando Pygocentrus nattereri, Gymnotus carapo, Astyanax abramis e Astyanax sp. da bacia do Igarapé da Fortaleza, estado do Amapá (Brasil). Os peixes foram coletados de outubro de 2012 a abril de 2013, e as quatro espécies de hospedeiros examinados estavam parasitados por 14 táxons de metazoários e um total de 580 parasitos foram coletados. Somente larvas de Contracaecum sp. foram comuns a todos os hospedeiros examinados e metacercárias de Posthodiplostomum sp. ocorreram em três espécies de hospedeiros, enquanto Ergasilus sp. foi encontrado somente em G. carapo. Monogeneas Urocleidoides affinis ocorreram somente em A. abramis e Astyanax sp., enquanto em P. nattereri foram encontradas outras cinco espécies de monogeneas e G. carapo outras três espécies. Portanto, houve uma predominância de ectoparasitos e entre os endoparasitos a predominância foi de estágios larvais. Este é o primeiro relato desses parasitos para P. nattereri, G. carapo, A. abramis e Astyanax sp. Made available in DSpace on 2018-07-05T01:18:10Z (GMT). No. of bitstreams: 1 CPAFAP2018Metazoariosparasitosdequatroespecies.pdf: 336102 bytes, checksum: 3b06ea7d1aad44ce602a87930cbdc949 (MD5) Previous issue date: 2018-07-04

Immunostimulants in farmed fish diets has been considered an effective approach to health management. This study aimed to assess antioxidant effects and resistance against pathogens of Colossoma macropomum (tambaqui) fed essential oil (EO) of M. piperita at 0%, 0.5%, 1.0% and 1.5% kg−1 commercial feed during 30 days. Tambaqui were challenged with Aeromonas hydrophila and did not present clinical signs of alterations. Higher hepatic catalase activity was observed in fish fed 1.0% of M. piperita EO, compared with 1.5%. Renal superoxide dismutase and glutathione peroxidase decreased in the fish fed M. piperita EO. Hepatic and renal lipid hydroperoxide increased among fish fed diets with 1.0 and 1.5% of EO. Tambaqui fed 1.0% of M. piperita EO showed respiratory activity increase, compared with 0.5%. Monocytes and PAS-GL were abundant in fish fed higher EO concentrations. Reduction in monogenoideans abundance was observed in fish fed 0.5 and 1.0% of EO. Although anti-helminth effects were observed, M. piperita EO in tambaqui diet did not promote leukocytes and lysozyme activity increases at the concentrations assessed. It can be suggested that other concentrations should be tested in future studies, as the combined use with other products, such as immunostimulants and probiotics. Made available in DSpace on 2018-03-15T00:35:46Z (GMT). No. of bitstreams: 1 CPAFAP2018Antioxidantseffectsandresistance.pdf: 161913 bytes, checksum: 44f7da506feeca4d82a79dcfeb2fe8d9 (MD5) Previous issue date: 2018-02-27

This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3%) was the most parasitized host, while C. ephippifer (6.7%) was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities. Made available in DSpace on 2018-04-07T00:33:14Z (GMT). No. of bitstreams: 1 CPAFAP2018ParasitesofornamentalfishcommercializedinMacapa.pdf: 546956 bytes, checksum: bb9305cd858debd8dad8c7fb3233e4b1 (MD5) Previous issue date: 2018-04-06

This paper describes the first study on parasite diversity in Auchenipterus nuchalis Spix & Agassiz, 1829 (Auchenipteridae). In 31 fish caught in a tributary of the Amazon River, 10,708 parasites were collected, such as Ichthyophthirius multifiliis, Piscinoodinium pilullare, Cosmetocleithrum striatuli, metacercariae of Posthodiplostomum sp, and larvae and adults of Procamallanus (Spirocamallanus) inopinatus. These parasite species showed aggregated dispersion, except for C. striatuli, which had a uniform dispersion. The component community of parasites showed a low Brillouin diversity (0.67 ± 0.27), low species richness (3.5 ± 0.8) and low evenness (0.43 ± 0.17), and it was characterized by the presence of species with high prevalence and abundance. Protozoan species were the prevalent parasites, which may be a consequence of the host?s mode of life, while the low presence of endoparasites in A. nuchalis suggests that this fish may occupy an intermediate trophic level in the food web. These data represent the first record of such parasite species for this host.

The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas, Cichla monoculus, Cichla ocellaris, Cichla jariina, Satanoperca jurupari, Leporinus friderici, Leporinus fasciatus, Hoplias malabaricus, Phractocephalus hemioliopterus, Serrasalmus altispinis, Pseudoplatystoma tigrinum and Potamotrygon motoro of the State Amapa´ and Para´, in northern Brazil. A total of 242 parasites, including Argulus elongatus, Argulus multicolor, Argulus juparanaensis, Argulus nattereri, Dolops discoidalis, Dolops longicauda, Braga patagonica, Braga fluviatilis, Livoneca guianensis and undetermined Lernaeidae, were collected from these hosts. The Argulus species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than D. discoidalis, was most abundant in the integument of A. gigas and P. tigrinum. Finally, the present study reported nine new hosts for the crustacean parasite species and expanded knowledge of the occurrence of some parasite species in the Jari River basin, in eastern Amazon.

This study evaluated the in vitro and in vivo antiparasitic efficacy of formalin against Dawestrema cycloancistrium, the effects on the physiological response of Arapaima gigas and the residual action on fish muscle after 96h of exposure. As regards the in vitro assay, 0, 22, 44, 66, 88, 110, 330, 660 and 880 mg L-1 formalin were tested. After 1h of exposure to 660 and 880 mg L-1 formalin, there was a 100% mortality of D. cycloancistrium as well as after 2h of exposure at 330 and 110 mg L-1 and 3h of exposure at 44, 66 and 88 mg L-1. Concerning the in vivo test, when fish were exposed to formalin at 0, 220, 330, 440 and 550 mg L-1, there was 100% survival at all concentrations and exposure times evaluated. Baths of 1h with 440 and 550 mg L-1 formalin showed 93.3% and 99.3% efficacy respectively. However, the baths of 12h with 55 and 66 mg L-1 formalin had the efficacy of 44.5% and 55.5% respectively. In 1h baths with 220, 330, 440 and 550 mg L-1 formalin, hematocrit, hemoglobin, number of total erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, plasma glucose levels, cortisol, total proteins, chloride, calcium, sodium, potassium and magnesium of the fish presented no differences in relation to the control values. However, in baths of 12h with 33, 44, 55 and 66 mg L-1 formalin, there was a decrease in hematocrit, plasma levels of calcium and chloride, and increased levels of glucose and cortisol, depending on the concentration of formalin used. In the fish muscle, the formalin residue decreased after 96h in all concentrations and periods evaluated, returning to values close to the control ones. The results indicate that formalin had its efficacy successfully proved in the treatment against D. cycloancistrium at higher concentrations such as 440 and 550 mg L-1 formalin and shorter exposure time (1h) without compromising fish homeostasis and consumer food safety. Statement of relevance: The manuscript represents original research on use of formalin in vitro and in vivo for treating infection by monogenoidean Dawestrema cycloancistrium in Arapaima gigas, the giant fish from Amazon. In the fish, muscle the residue levels of formalin after exposure was also investigated. Formalin have efficacy in the treatment against D. cycloancistrium at higher concentrations (440 and 550 mg.L-1) of formalin and shorter exposure time (1h) and without compromising A. gigas homeostasis and consumer food safety.

The present study investigated the fauna of metazoan parasites of a Geophagus proximus population from the lower Tapajós River, in the state of Pará, northern Brazil. A total of 137 monogeneans were collected from the gills of G. proximus , including Sciadicleithrum kritskyi , Sciadicleithrum paranaensis and Sciadicleithrum geophagi , while 119 Raphidascaris (Sprentascaris ) lanfrediae nematodes and 28 metacercariaes of digenea undetermined were collected from the intestine. Hosts harboring four species of parasites were predominant. The parasites had an aggregated dispersion pattern. The present study represents the first record of S. geophagi parasitizing G. proximus , increasing the geographic distribution of these parasite species to the Tapajós River basin. Made available in DSpace on 2017-04-11T16:04:15Z (GMT). No. of bitstreams: 1 CPAFAP2017MetazoanparasitesofGeophagus.pdf: 2627868 bytes, checksum: 867c6fbb3ea8b35ccf1160f02dfd2c40 (MD5) Previous issue date: 2017-04-10

The hematological and biochemical responses of pirarucu fingerlings (Arapaima gigas) fed with diets containing different concentrations of a glucomannan product derived from yeast and algae were evaluated in order to ascertain the effect of these diets on fish physiology. Four treatments were conducted, with three replications, with 12 fish in each tank. The product evaluated (MycosorbA+®) was incorporated into the commercial diet, at four concentrations: 0, 1, 2 and 4 g.kg-1, called M0%, M0.1%, M0.2% and M0.4%, respectively. After 45 days of feeding, blood samples from six fish in each replicate were collected to perform the analyses. Their weight and length were determined to calculate the condition factor and weight gain, but no differences (P > 0.05) were observed among the treatments. No changes to the hematocrit, hemoglobin or erythrocyte levels or to the hematimetric indices of the pirarucus were observed. The glucose and triglyceride levels of the pirarucus in the M0.1% and M0.2% groups were significantly lower than those of the M0% group. The M0.2% group showed higher albumin levels (P < 0.05) than M0% and M0.4%. The M0.4% group showed a total cholesterol level that was significantly higher than in all other treatments. MycosorbA+® contributed towards increasing the levels of defense cells in A. gigas. It would be possible to use this product at concentrations of between 0.1% and 0.2%, given that they increase the levels of some defense cells and plasma albumin concentrations, without changes to hematological parameters, cholesterol and triglyceride plasma levels or condition factor.

This study investigated the parasitic fauna of Cichlasoma bimaculatum of a tributary from the Amazon River system, northern Brazil. The prevalence of infection was 94.6 % and, in total, 428 267 parasites, such as Ichthyophthirius multifiliis, Piscinoodinium pillulare (Protozoa), Gussevia arilla (Monogenoidea), Posthodiplostomum sp. (Digenea) and Procamallanus (Spirocamallanus) inopinatus (Nematoda) were collected. However, the dominance was mainly of I. multifiliis, while P. (S.) inopinatus was the parasite species with the lower levels of prevalence and abundance of infection. These parasite species showed an aggregated dispersion pattern. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and abundance, specifically ectoparasites, and a low number of endoparasites. The observed pattern is explained by the mode of life of the host and it is suggested that C. bimaculatum occupies a low trophic level at the food web.

This study investigated the metazoan parasite fauna in Peckoltia braueri and Pterygoplichthys pardalis from a tributary of the Amazon River system, in northern Brazil. In P. braueri, 630 parasites were collected, belonging to Unilatus unilatus, Nothogyrodactylus sp., Genarchella genarchella, Proteocephalus sp., Gorytocephalus elongorchis, Dolops longicauda and Hirudinea gen. sp., with a dominance of monogenean species. In P. pardalis, 120 parasites were collected, belonging to U. unilatus, Acanthostomum gnerii and Gorytocephalus elongorchis, and this acanthocephalan was the dominant species. In both hosts, the parasites presented clumped distribution, high prevalence, low abundance, low Shannon diversity, and low species richness, with a predominance of helminth species. In P. braueri, host length was positively correlated with parasite species richness and Shannon index. There was no difference in the body condition of parasitized and non-parasitized fishes in either host. This was the first report of these parasites in P. braueri and P. pardalis.

This study compared the blood characteristics of hybrid tambacu (Colossoma macropomum x Piaractus mesopotamicus) from three fish farms in the Macapá, State of Amapa (Brazil), which has a similar management. There were differences in the levels of dissolved oxygen in the water and pH in the ponds of the fish farms, but condition factor showed good body condition of the fish. In blood of tambacu were identified thrombocytes, lymphocytes, monocytes, neutrophils, PAS-positive granular leukocytes (PAS-GL) and eosinophils. Plasma glucose and protein levels, hematocrit, total leucocyte count, total thrombocytes count, monocytes, neutrophils and eosinophils count were similar among the three fish farms. However, hemoglobin concentration, total erythrocytes count, mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), number of lymphocytes and PAS-GLshowed differences among fish of these fish farms. Although the results showed a relative similarity between the blood parameters in the fish of the different fish farms, but the management conditions regarding the water quality in the ponds and food should be improved to increase the productivity in these fish farms.

This study was the first investigation on the parasites of Triportheus rotundatus, a Characiformes fish from the Amazon, in Brazil. All the fish collected (100%) in a tributary from the Amazon River system were infected by one or more parasite species. The mean species richness of parasites was 4.9 ± 0.9, the Brillouin index was 0.39 ± 0.16, the evenness was 0.24 ± 0.09 and the Berger-Parker dominance was 0.81 ± 0.13. A total of 1316 metazoan parasites were collected, including Anacanthorus pithophallus, Anacanthorus furculus, Ancistrohaptor sp. (Dactylogyridae), Genarchella genarchella (Derogenidae), Posthodiplostomum sp. (Diplostomidae), Procamallanus (Spirocamallanus) inopinatus (Camallanidae), Echinorhynchus paranensis (Echinorhynchidae) and Ergasilus sp. (Ergasilidae), but monogenoideans were the dominant parasites. These parasites presented an aggregate dispersion pattern, except for P. (S.) inopinatus, which showed a random dispersion pattern. The body conditions of the hosts were not affected by the parasitism levels. This first report of these parasites for T. rotundatus indicates that the presence of ectoparasites and endoparasites was due to hosts behavior and availability of infective stages in the environment, and this was discussed. Made available in DSpace on 2017-04-13T23:55:12Z (GMT). No. of bitstreams: 1 CPAFAP2017Firststudyoncommunitiesofparasites.pdf: 5705681 bytes, checksum: 375b63ec8409516f87635509013d2204 (MD5) Previous issue date: 2017-04-13

This study examined the in vitro and in vivo, histopathological, anti-parasitic and hematopathological effects of the essential oil of Lippia origanoides on Colossoma macropomum. Essential oil concentrations of 10, 20, 40, 80, 160 and 320 mg·L-1 were tested in vitro against monogenoideans (Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri) from the gills of C. macropomum. Concentrations of 320 and 160 mg·L-1 were 100% effective against these parasites within 20 and 60 min of exposure, respectively. The 80 mg·L-1 concentration was approximately 80% effective with 3 h of exposure, reaching 100% with 6 h of exposure. The 40 mg·L-1 concentration was also 100% effective with 6 h of exposure. The other concentrations were only weakly effective in vitro. Parasite mortality in controls (water or water + alcohol) began after 3 h, with 100% mortality after 8 h. In vivo tests, in which fry of C. macropomum were placed in baths with 20 mg·L-1 of the essential oil for 60 min, and 40 mg·L-1 for 30 min, did not lead to reductions in parasite abundances. In addition, the essential oil had an anaesthetic effect on fish, increased total protein levels, increased monocyte and neutrophil numbers, and reduced haematocrit. Slight to moderate and severe damage was observed in the gills of C. macropomum fingerling immediately after exposure to the essential oil, and 24 h after the treatments were applied, with no difference between treatments. Histological changes observed in the gills after exposure to concentrations of 20 and 40 mg·L-1 of L. origanoides essential oil were: hyperplasia and fusion of the lamellar epithelium, capillary dilation, displacement of the lamellar epithelium, and lamellar aneurism and epithelial rupturing with haemorrhaging. Oedema, mucous and chloride cell proliferation, lamellar hypertrophy, congestion and necrosis were less frequently observed. It can be concluded that the essential oil of L. origanoides was dose-dependent in vitro effect against monogenoidean parasites of C. macropomum. Unfortunately, the low concentrations tolerated by the fish in the vivo assay (20 and 40 mg·L-1) was not effective. Statement of relevance: The manuscript represents original research on use of the essential oil of Lippia origanoides against ectoparasites of Colossoma macropomum, an important finfish of Amazon region. This manuscript includes treatment in vitro against monogenoideans, and in vivo against protozoans and monogenoideans. Besides, histopathological and hematological analysis of the fish exposed to different concentrations of L. origanoides, a medical plant from North, Central and South America, were performed.

Aeromonas hydrophila is causing substantial economic losses in world aquaculture. This study determined the tolerance limit (LD50-96h) of A. hydrophila in Arapaima gigas, and also investigated the clinical signs after intradermal inoculation.

The present study compared the community of parasites in populations of Triportheus angulatus and T. curtus from a tributary of the Amazon River in northern Brazil. All hosts had one or more parasite species, 862,687 parasites were collected from T. curtus and 302,008 from T. angulatus. Species richness of parasites, Shannon diversity index and evenness index were higher for T. angulatus. The parasite communities of both hosts was similar (99%) and composed by Ichthyophthirius multifiliis, Anacanthorus pitophallus, metacercariae and Procamallanus (Spirocamallanus) inopinatus, with dominance of I. multifiliis. However, low infection level by Piscinodinium pilullare, Dolops sp. and Contracaecum larvae occurred only in T. angulatus, and Spironucleus sp. was found only in T. curtus. There were differences in the prevalence, intensity and mean abundance for some parasites of both hosts. There was aggregated dispersion of parasites in both hosts, but the infection of P. (S.) inopinatus in T. angulatus showed a random dispersion. For T. angulatus and T. curtus, the diversity and abundance of parasites were influenced by the host size. This was the first report of these parasite species for T. curtus, as well as of I. multifiliis, P. pilullare, Dolops sp., P. (S.) inopinatus and Contracecum sp. for T. angulatus.

The aim of this study was to investigate the component community of parasite metazoans of Piaractus brachypomus in the lower Amazon River, northern Brazil. From 34 necropsied fish, 27,384 metazoan parasites were collected, such as Anacanthorus spathulatus, Mymarothecium viatorum and Notozothecium janauachensis (Monogenoidea); Spectatus spectatus and Contracaecum sp (Nematoda); Clinostomum marginatum and Dadaytrema oxycephala (Digenea); and Argulus carteri and Ergasilus sp. (Crustacea). The dominant species was S. spectatus followed by monogenoidean species, and there was aggregated dispersion of parasites, except for D. oxycephala and Contracaecum sp., which presented random dispersion. Positive correlation among the abundance of the three monogenoideans species were found, thus indicating that there was no competition between the species of these parasites on the gills of hosts. The abundances of some parasite species showed positive correlations with the size of the hosts, but the condition factor of the fish was not affected by the parasitism levels. It showed that this host had a metazoan community characterized by high species richness of metazoans, low evenness and high diversity of parasites, with prevalence of endoparasites, including larval stages. This was the first record of C. marginatum, A. carteri, Ergasilus sp. and Contracaecum sp. for P. brachypomus.

O ambiente aquático é suscetível à contaminação por pesticidas, sabendo-se que inclusive a diluição destes compostos químicos pode acarretar em diversas variações na homeostase dos vertebrados aquáticos. As consequências destes agentes podem ser diretas e/ou indiretas, manifestando-se em níveis bioquímicos, fisiológicos e morfológicos do organismo, como também por reflexos estruturais na dinâmica das populações e comunidades. Deste modo o objetivo do presente estudo foi avaliar os possíveis riscos e efeitos no tecido sanguíneo em relação ao uso de um biopesticida a base de Bacillus thuringiensis em uma espécie de peixe da bacia amazônica muito utilizada em cultivo e consumo humano ? o Tambaqui (Colossoma macropomum).

This study investigated the parasite communities of wild Acestrorhynchus falcatus and Acestrorhynchus falcirostris populations living in sympatry in Brazilian Amazon. In these two hosts, a total of 12 parasite species e 1-9 parasite species were found per fish, and 10 of these species are metazoans. Eight species of parasites were common to both host species and four of them exhibited differences in abundance and/or prevalence. Parasite communities of the hosts were taxonomically similar (83%) and composed of both ectoparasites and endoparasites, and characterized by high prevalence and high abundance of endoparasites and an aggregated dispersion pattern. For A. falcirostris, the dominant parasite was Ichthyophthirius multifiliis, and for A. falcatus, it was Piscinoodinium pillulare. Shannon diversity and Berger-Parker dominance were similar for both hosts, while the parasites species richness and evenness showed differences influenced by the ectoparasites species. These two populations of hosts that inhabited the same geographical area had different sizes, but were exposed to the same infective stages, and acquired qualitatively and quantitatively similar endoparasites community, thus indicating that the amounts and types of prey congeneric that they were eating were similar. Therefore, the overlap in the same occurrence area play an important role in the parasite communities to these phylogenetically related hosts.

Os estudos sobre os parasitos e doenças parasitárias são de grande interesse para a piscicultura, uma vez que podem afetar o crescimento dos peixes. O objetivo deste estudo foi investigar a fauna parasitária e relação parasito-hospedeiro em Colossoma macropomumx Piaractus brachypomus(tambatinga) de 10 pisciculturas do estado do Amapá, Amazônia. Dos 503 peixes examinados, 63,1% estavam parasitados e 49.299.189 parasitos foram coletados, tais como Ichthyophthirius multifiliis, Piscinoodinium pillulare, Trichodinasp., Tetrahymenasp., Anacanthorus spathulatus, Linguadactyloides brinkmanni, Mymarothecium boegeri, Notozothecium janauachensis, Procamallanus (Spirocamallanus)inopinatus, Neoechinorhynchus buttneraee Perulernaea gamitanae. Porém, a dominância foi de I. multifiliis, seguida de P. pillularee monogenoideas, parasitos que apresentaram padrão de dispersão agregado juntamente com P. gamitanae. Houve correlação positiva do comprimento dos hospedeiros com a prevalência parasitária total, bem como do tamanho dos peixes com a abundância de I. multiliis, P. pillulare, monogenoideas e P. gamitanae, mas os níveis infecção não influenciaram o fator de condição relativo dos hospedeiros. A ocorrência de ectoparasitos foi favorecida pelo manejo e pobre condição sanitária das pisciculturas, mas a presença de espécies de endoparasitos foi devido ao abastecimento dos viveiros com água provenientes de corpos de água naturais. Este foi primeiro relato de I. multiliis, P. pillulare, Trichodinasp., Tetrahymenasp., A. spathulatus, N. janauachensis, N. buttneraee P.(S.) inopinatus para tambatinga no Brasil.

Este estudo investigou os parâmetros hematológicos de Mylossoma duriventre Cuvier, 1817 da bacia do Rio Solimões, estado do Amazonas, Amazônia central, no Brasil. Variações intraespecíficas foram observadas para os parâmetros investigados, mas o hematócrito foi o parâmetro com menor variação. O número de eritrócitos mostrou correlação altamente positiva com o hematócrito. Nas extensões sanguíneas M. duriventre foram quantificados e caracterizados linfócitos, monócitos, neutrófilos, eosinófilos e leucócitos granular PASpositivo, mas houve predominância de linfócitos e neutrófilos. Tais leucócitos apresentaram características similares a de outras espécies de serrasalmídeos. Porém, foram observadas variações interespecíficas em alguns parâmetros investigados quando comparados a outros Serrasalmidae e Characidae da literatura. Este foi o primeiro estudo sobre parâmetros hematológicos de M. duriventre e os resultados obtidos poderão servir de comparação para outros estudos com esse peixe em outros ambientes.

The aim of this study was to investigate the parasitic endohelminth fauna of Metynnis hypsauchen from Jari River basin, in Brazilian Amazon. The 30 examined fish were parasitized by one or more species of endoparasites. A total of 4337 parasites were collected including Dadayus pacuensis, Procamallanus (Spirocamallanus) inopinatus, Spinoxyuris oxydoras, Contracaecum sp. and Acanthocephala gen. sp. However, there was a dominance of D. pacuensis followed by S. oxydoras, and all parasites showed an aggregate dispersion. There was positive correlation between the abundance of P. (S.) inopinatus and the length and abundance of D. pacuensis with the weight of the host. The body condition of the hosts was not affected by parasitism. This first study on parasites of M. hypsauchen showed that this fish is an intermediate or definitive host for some species of these parasites.

Foram avaliadas as infestações parasitárias em híbridos tambatinga (Colossoma macropomum e Piaractus brachypomus) criados em tanque-rede no estado do Amapá, norte do Brasil. A boca, opérculos, brânquias e trato gastrointestinal de 50 espécimes foram examinados para coleta de protozoários e metazoários. Dos peixes necropsiados, 60% estavam com as brânquias parasitadas por Ichthyophthirius multifiliis (Ciliophora), Piscinoodinium pillulare (Dinoflagellida) e Mymarothecium boegeri (Monogenoidea). Houve baixa comunidade parasitária constituída por elevado parasitismo por protozoários e baixo parasitismo por monogenoidea, que ocorreu em 10% dos hospedeiros. Assim, a dominância foi de I. multifiliis e P. pillulare, parasitos que apresentaram dispersão agregada nos hospedeiros. O parasitismo não teve efeito sobre as condições corporais dos hospedeiros, uma vez que o fator de condição relativo (Kn) de peixes parasitados (Kn = 0,999 ± 0,008) e não parasitados (Kn = 1,000 ± 0,018) foi similar, provavelmente devido aos moderados níveis de infestação por ectoparasitos. Este primeiro estudo sobre níveis de infestações parasitárias em híbridos tambatinga do Brasil mostrou uma baixa riqueza de espécies de parasitos.

The parasitic fauna of wild Osteoglossum bicirrhosum from central Amazon (Brazil) and wild Astronotus ocellatus from eastern Amazon (Brazil) as well as the host-parasite relationship were evaluated. 87.5% O. bicirrhosum were parasitized only by Gonocleithrum aruanae (Monogenoidea). 92.8% A. ocellatus were parasitized by Ichthyophthirius multifiliis (Ciliophora), Gussevia asota (Monogenoidea), Posthodiplostomum sp. metacercariae (Diplostomidae), Procamallanus inopinatus adults and Contracaecum larvae (Anisakidae). High levels of infection by G. aruanae occurred in O. bicirrhosum while in A. ocellatus the highest levels of infection were caused by helminthes ectoparasites such as G. asota, and endoparasites such as Posthodiplostomum sp., P. inopinatus and Contracaecum sp. There was a significant (p>0.05) negative correlation between the intensity of helminthes species and the relative condition factor (Kn) from A. ocellatus, indicating that these parasites are pathogenic for hosts. The parasite fauna of O. bicirrhosum was scarce, while the parasites for A. ocellatus were mainly helminthes species, including adults and larval forms. Such differences on parasites fauna of both omnivore hosts may due to their history life as well as environmental and biological factors.

Os parasitos têm sido reconhecidos como importantes componentes dos ecossistemas. Esses usam o ambiente para a sua transmissão e podem infectar diversas espécies de peixe no ecossistema. O presente estudo investigou a ecologia parasitária em Squaliforma emarginata e Harttia duriventris da bacia Igarapé Fortaleza, região de Macapá, estado do Amapá, Norte do Brasil. Para ambos os peixes houve similar nível de infecção por Ichthyophthirius multifiliis (Ciliophora), parasito dominante e com dispersão agregada. Spironucleus sp. (Hexamitidae) ocorreu somente nas brânquias de H. duriventris, enquanto Trinigyrus mourei (Monogenoidea) e Procamallanus inopinatus (Camallanidae) foram encontrados somente S. emarginata. O índice de Brillouin, riqueza de espécies de parasitos, uniformidade e dominância de Berger-Parker foram maiores em S. marginata, mas para ambos os hospedeiros a comunidade parasitária foi caracterizada por baixa diversidade e baixa uniformidade. Em H. duriventris e S. emarginata, o baixo parasitismo não afetou o fator de condição relativo (Kn) dos hospedeiros. Em S. emarginata houve correlação positiva da abundância de I. multifiliis com o comprimento, peso e Kn dos hospedeiros, enquanto que em H. druventris somente o peso e Kn mostram correlação com a abundância desse ciliado. Este foi o primeiro registro de I. multifiliis, Spironucleus sp. e P. inopinatus para H. duriventris e S. emarginata.

Specimens of Braga patagonica Schiödte & Meinert, 1884 (Isopoda: Cymothoidae) from freshwater fishes deposited in Ichthyological Collection of Amazon National Research Institute (INPA), in central Amazon and from fishes from eastern Amazon (Brazil) were investigated. Prevalence, infection intensity and body measures of B. patagonica for different populations of this cymothoid in wild fishes species from Amazon were carried out. Four species of Serrasalmidae, one Characidae, one Cichlidae, one Cynodontidae, one Curimatidae, one Acestrorhynchidae and one Sciaenidae were recorded as new hosts for B. patagonica in the Amazon. This study indicates a low intensity and low parasitic specificity of B. patagonica, and also recorded the first parasitism by this ectoparasite in farmed Colossoma macropomum, describing its highly pathogenic effect.

We investigated the ecological relationships between parasites and the host silver arowana Osteoglossum bicirrhosum Cuvier, 1829 from Amazonian basin, in Brazil. A total of 1,570.539 parasites belonging to different taxa were found including Ichthyophthirius multifiliis, Piscinoodinium pillulare (Protozoa), Gonocleithrum aruanae, Gonocleithrum planacrus, Gonocleithrum coenoideum (Monogenoidea) and Camallanus acaudatus (Nematoda); all had an aggregated dispersion. Made available in DSpace on 2015-02-11T09:05:42Z (GMT). No. of bitstreams: 1 CPAFAP2014ParasitediversityOsteoglossum.pdf: 130757 bytes, checksum: 1e9be5cd34de3aefee63bce2d6cad357 (MD5) Previous issue date: 2015-01-20

This study is the first investigation on seasonal dynamics of parasites component community of the Aequidens tetramerus from an Amazon River tributary, in Northern Brazil. A total of 239,2407 parasites were recovered from 92 hosts examined from February to October 2011. Such parasites included Ichthyophthirius multifiliis, Tripartiella tetramerii and Trichodina nobilis (Protozoa), Dolops longicauda (Argulidae), Gussevia alioides, Gussevia disparoides (Monogenoidea), Digenea metacercarie, Pseudoproleptus larvae, Anisakidae larvae (Nematoda), Proteocephalidea plerocercoid (Eucestoda) and Gorytocephalus spectabilis (Acanthocephala). Ciliates were the most dominant and abundant taxon, while cestodes were the least prevalent. The parasites showed seasonal variation in their infection dynamics associated with environmental changes during the Amazonian drainage season, except the infection with I. multifiliis. The parasites community in A. tetramerus was also characterized by higher diversity, species richness and uniformity during the drainage season when compared to Amazon flood season. With the exception of T. tetramerii, these parasite species are new records for A. tetramerus.

Este estudo relata a primeira ocorrência de protozoários nas brânquias de tamoatá Hoplosternum littorale (Hancock 1828) (Siluriformes: Callichthyidae) no Brasil. Dos espécimes examinados, no período de julho a agosto de 2011, 95,3% estavam com as brânquias parasitadas por protozoários Ichthyophthirius multifiliis (Ciliophora) e/ou Piscinoodinium pillulare (Dinoflagellida), sendo que os maiores índices de infecção foram causados por I. multifiliis. A abundância desses parasitos não foi influenciada pelo tamanho dos peixes e não afetou o fator relativo de condição (Kn) dos hospedeiros. Este é o primeiro relato de índices epidemiológicos para H. littorale na Amazônia brasileira.

The present work morphologically characterizes Paratrichodina africana from the gills of wild and farmed Nile tilapia from Northern Brazil (eastern Amazonia). Ninety fish were captured for parasitological analysis in Macapá, State of Amapá, from a wetland area bathed by the Amazon River commonly called ?Ressaca do Zerão? (n = 52), as well as from a local fish farm (n = 38). Wet smears of the skin and gills of the captured fish were air dried at room temperature and impregnated with silver nitrate by Klein?s method for posterior examination of the adhesive disc structures. Total prevalence of parasitism was 16.6% (23% in fish from wetland and 7.8% in farmed fish). Characterized as a small‑sized trichodinid, it presented the following measures: 33.2 ± 4.7 μm body diameter, 17.5 ± 2.1 μm adhesive disc, 10.0 ± 0.9 μm denticulate ring, and 22.6 ± 2.0 denticles. Paratrichodina africana reported in this study strongly resembles those described for other localities, but it differs by presenting greater body length. This is the fourth report of P. africana parasitizing a host fish.

This work is the first study on parasitic fauna of Curimata cyprinoides Linnaeus, 1766 (Curimatidae) and the host-parasite relationship. The total of 154,740 parasites such as Ichthyophthirius multifiliis (Ciliophora), trophozoite of Spironucleus sp. (Hexamitidae), Urocleidoides sp. (Monogenoidea), Digenea gen. sp. and Polymorphus sp. (Polymorphidae) were collected. The component community showed low diversity (HB = 0.004 ± 0.020) and parasite species richness (1.4 ± 0.6). However, I. multifiliis and Urocleidoides sp. were prevalent and with higher intensity on the host population and also aggregated the distribution pattern. The occurrence of these ectoparasites in C. cyprinoides may be a consequence of its alimentary diet. Positive correlation between the abundance and size of I. multifiliis and the relative condition factor of the host were observed and discussed. These data represent increased knowledge of the biology of these parasites. Furthermore, this study expanded the geographic distribution of some parasite species for this new host from Brazil.

The objective of this work was to evaluate the parasitic fauna of hybrid tambacu (Colossoma macropomum x Piaractus mesopotamicus) from fish farms and the host; parasite relationship. A hundred and fourteen fish were collected from four fish farms in Macapá, in the state of Amapá, Brazil, 80.7% of which were infected by: Ichthyophthirius multifiliis (Ciliophora); Piscinoodinium pillulare (Dinoflagellida); Anacanthorus spatulatus, Notozothecium janauachensis, and Mymarothecium viatorum (Monogenoidea); Neoechinorhynchus buttnerae (Acanthocephala); Cucullanus colossomi (Nematoda); Perulernaea gamitanae (Lernaeidae); and Proteocephalidae larvae (Cestoda). A total of 8,136,252 parasites were collected from the examined fish. This is the first record of N. buttnerae, C. colossomi, N. janauachensis, M. viatorum, and Proteocephalidae for hybrid tambacu in Brazil. Ichthyophthirius multifiliis was the most prevalent parasite, whereas endohelminths were the less. A positive correlation was observed between number of I. multifiliis and total length and weight of fish, as well as between number of P. gamitanae and total length. The infection by I. multifiliis had association with the parasitism by Monogenoidea. Low water quality contributes to high parasitism of hybrid tambacu by ectoparasites, which, however, does not influence the relative condition factor of fish.

This study presents the first report of infection by Linguadactyloides brinkmanni Thatcher & Krytsky, 1983 (Monogenoidea, Dactylogyridae, Linguadactyloidinae) on the gills of hybrid tambatinga (Colossoma macropomum x Piaractus brachypomus) from fish farms from the city of Macapá, state of Amapá, Brazil. Out of 201 hybrid tambatinga examined, ten were infected by L. brinkmanni (prevalence= 4.9%). From these hosts, 21 specimens of L. brinkmanni were collected and the mean intensity of infection was 2.1 (1-4 parasites/host). This study expands the distribution of this monogenoidean for a new host.

This study describes the parasitic fauna of Mylossoma duriventre caught at Lake Coari, a tributary of the middle Solimões River, in the state of Amazonas (central Amazon, Brazil) and the relative condition factor (Kn). Out of 70 necropsied specimens, 90% had the gills parasitized by the helminth Anacanthorus paraspathulatus Kritsky, Boeger & Van Every, 1992 (Dactylogyridae: Anacanthorinae) and the intestine by Eustrongylides Jägerskiöld 1909 (Nematoda: Dioctophymatidae) larvae. A total of 19,763 specimens of A. paraspathulatus were collected, but the infection by Eustrongylides sp. larvae seemed to be accidental, after all, only three hosts were trophically infected. However, there was no significant difference (p

This study describes the parasitic fauna of Oxydoras niger from the Coari Lake, tributary of the medium Solimões River, State of Amazonas, Brazil, and the relationship between the number of Monogenoidea and the condition factor. From a total of 27 examined fish, 70.3% were parasitised by at least one parasite species as follows: Ichthyophthirius multifiliis (Protozoa), Chilodonella sp. (Protozoa), Cosmetocleithrum gussevi, C. confusus, C. parvum and Cosmetocleithrum sp. (Monogenoidea), Paracavisona impudica (Acanthocephala), Cucullanus grandistomis (Nematoda), Proteocephalus kuyukuyu (Cestoda) and Dadaytrema sp. (Digenea). Monogenoidea helminthes were the most prevalent parasite when compared to protozoan and intestinal helminthes. This study showed that O. niger has a great parasite diversity composed mainly of monogenoideans followed by acanthocephalan and digenean. This is the first record of Dadaytrema in O. niger from the Brazilian Amazon. There was a positive correlation between the number of monogenoideans and the condition factor (Kn) of fish, and with this mean intensity of infection, fish welfare was not affected. Este estudo descreve a fauna parasitária de Oxydoras niger do lago Coari, tributário do médio rio Solimões, estado do Amazonas, Brasil, e a relação entre o número de Monogenoidea e o fator de condição. De um total de 27 peixes examinados, 70,3% estavam parasitados por pelo menos uma espécie de parasito como segue: Ichthyophthirius multifiliis (Protozoa), Chilodonella sp. (Protozoa), Cosmetocleithrum gussevi, C. confusus, C. parvum and Cosmetocleithrum sp. (Monogenoidea), Paracavisona impudica (Acanthocephala), Cucullanus grandistomis (Nematoda), Proteocephalus kuyukuyu (Cestoda) and Dadaytrema sp. (Digenea). Helmintos monogenóideos foram os mais prevalentes quando comparados com protozoários e helmintos intestinais. Este estudo mostrou que O. niger apresenta grande diversidade de parasitos composta principalmente de monogenóideos seguidos de acantocéfalos e digenéticos. Este foi o primeiro relato de Dadaytrema em O. niger na Amazônia brasileira. Foi observada correlação positiva entre o número de monogenóideos e o fator de condição (Kn) e nessa intensidade média de infecção o bem-estar do peixe não foi afetado.

The purpose of this work was to determine the mean lethal concentration (LC50-96h) of copper sulfate (CuSO4) for juveniles Colossoma macropomum (Characidae), to evaluate the effectiveness of different concentrations of CuSO4 on elimination of parasites, as well as to study the effects of CuSO4 on blood parameters after short-term exposure. After determination of the LC50-96h from 17.5 mg L-1 of CuSO4, it was investigated the effects of exposure for 48 h to 1.75, 4.37 and 8.75 mg L-1 of CuSO4, on parasites and blood parameters. In gills and skin, concentrations of 4.37 and 8.75 mg L-1 of CuSO4 eliminated Monogenoidea Anacanthorus spathulatus. In fish exposed to different concentrations of CuSO4, plasma total protein, chloride, potassium, glucose and copper levels, hemoglobin and hematocrit were similar to controls, whereas sodium levels presented decrease in fish exposed to 1.75 and 4.37 mg L-1. Red blood cell counts decreased in fish exposed to different three concentrations of CuSO4, while the Mean Corpuscular Volume (MCV) increased. However, exposure to 8.75 mg L-1 of CuSO4 caused decrease on total leukocytes, lymphocytes, neutrophils and PAS-positive granular leukocytes (PAS-GL) number when compared to control fish.

This study describes the parasitic fauna and the host-parasite relationship of Semaprochilodus insignis Jardine, 1841 from Coari Lake, a tributary of the middle Solimões River (state of Amazonas, Brazil) in Central Amazonia. Of 56 fish examined, 23.2% had gills parasitized by Gyrodactylus Gemini Ferraz, Shinn & Sommerville 1994 (Monogenoidea: Gyrodactylidae), and the intestine by Procamallanus inopinatus Travassos, Artigas & Pereira, 1928 (Nematoda: Camallanidae). The highest rates of infection were caused by G. gemini. Even though the relative condition factor (Kn) was not affected by parasitism, there was a positive correlation between the intensity of both helminthes, the Kn and the total length of the hosts. This is the first report on the parasitic fauna of S. insignis with occurrences of G. gemini and P. inopinatus for this Neotropical host from the Amazonia.

This study aimed to report infection by metacercariae of the genera Posthodiplostomum Dubois, 1936 (Diplostomidae) and Herpetodiplostomum Dubois, 1936 (Proterodiplostomidae) in the gills of Oscar Astronotus ocellatus Agassiz, 1831 (Cichlidae) from Lake Pracuúba, in the municipality of Pracuúba, State of Amapá (eastern Amazonia), Brazil. Out of 202 A. ocellatus examined, 142 had gills infected by metacercariae of Herpetodiplostomum sp. (prevalence= 70.3%) and Posthodiplostomum sp. (prevalence= 59.4%). However, 97 hosts were infected by both metacercariae species (prevalence= 48.0%). A total of 1123 specimens of Herpetodiplostomum sp. and 463 specimens of Posthodiplostomum sp. were collected and the mean intensity of infection was 7.8 ± 11.6 and 3.9 ± 4.4, respectively. This is the first report of Digenea in A. ocellatus.

Farming of native carnivore fish species has drawn attention due to their promising use in aquaculture. Among these species, tucunaré of the genus Cichla stand out, them being of high economical interest for sport fishing and Amazon's industry of ornamental fish. The present study describes the weight-length relationship (WLR), relative condition factor (Kn), red blood cell parameters, thrombocytes and leukocytes count of Cichla temensis Humboldt, 1821, farmed in central Amazon. Fish that underwent food training during fingerling culture received extruded ration containing 45% of crude protein during fattening, and had Kn with values from 0.925-1.199, which indicated good health condition during the culture. The equation obtained from the WLR was W = 0.0073Lt3.1435, indicating an isometric growth, which is the desirable for fish of fish farm. Red blood cell counts, total thrombocyte and leukocyte counts, hematocrit, hemoglobin concentration, mean corpuscular volume (MCV), concentration of mean corpuscular hemoglobin (MCHC), lymphocytes, monocytes and neutrophils had intra-specific variation. A significant (p