The aim of this study was to investigate parasites crustacean fauna in ,, ,, ,, ,, ,, and of the State Amapá and Pará, in northern Brazil. A total of 242 parasites, including ,, ,, ,, , and undetermined Lernaeidae, were collected from these hosts. The species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than, was most abundant in the integument of and. 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.

Among Kinetoplastida, the Trypanosoma is the genus with the highest occurrence infecting populations of marine fish and freshwater in the world, with high levels of prevalence, causing influences fish health and consequent economic losses, mainly for fish populations in situation stress. This study investigated infections of Hypostomus spp. by Trypanosoma spp. and leeches, as well as blood parameters of this host in the network of tributaries of the Tapajós River in the state of Pará, in the eastern Amazon region in Brazil. Of the 47 hosts examined, 89.4% were parasitized by Trypanosoma spp. and 55.4% also had leeches attached around the mouth. The intensity of Trypanosoma spp. increased with the size of the host, but the body conditions were not influenced by the parasitism. The number of red blood cells, and hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin (MCH), total number of leukocytes and thrombocytes showed variations and negative correlation with the intensity of Trypanosoma spp. in the blood of the hosts. The results suggest that the leeches were vectors of Trypanosoma spp. in Hypostomus spp.

Myxozoans are a diverse group of parasitic cnidarians, with some species recognized as serious pathogens to their hosts. The present study describes 2 new myxobolid species (Myxobolus figueirae sp. nov. and Henneguya santarenensis sp. nov.) infecting skin and gill filaments of the Amazonian pimelodid fish Phractocephalus hemioliopterus, based on ultrastructural, histology and phylogenetic analysis. The fish were caught in the Amazon River, Pará, Brazil. The plasmodial development of M. figueirae sp. nov. was in the dermis and those of H. santarenensis sp. nov. were of the intralamellar type. For both species, the plasmodia were surrounded by a connective tissue layer, but there was no inflammatory infiltrate. For M. figueirae sp. nov., mature spores were ovoid measuring 9.1 to 10 (9.5 ± 0.3) µm in length, 5.8 to 6.9 (6.4 ± 0.3) µm in width and 4.4 to 4.5 (4.5 ± 0.1) µm in thickness. Two polar capsules were elongated and of unequal size. For H. santarenensis sp. nov., mature spores were ellipsoidal in the frontal view, measuring 26.3 to 36.1 (31.9 ± 3) µm in total length, 9.6 to 11.9 (10.8 ± 0.5) µm in body length, 3.7 to 4.9 (4.3 ± 0.3) µm in width and 16.6 to 25.6 (21 ± 3.1) µm in caudal process. The polar capsules were elongated and of equal size. Phylogenetic analysis, based on partial small subunit ribosomal DNA (SSU rDNA) sequences and using the closest myxozoan sequences to each one of the species studied here based on previous GenBank data, showed M. figueirae sp. nov. and H. santarenensis sp. nov. clustering in distinct lineages. While H. santarenensis sp. nov. clustered in a well-supported subclade composed of Henneguya species that infect gills of South American pimelodid hosts, M. figueirae sp. nov. clustered in a weakly supported subclade containing parasite species of bryconid hosts.

Traira (Hoplias malabaricus) is a neotropical fish that is widely distributed in freshwater environments in South America. In the present study, we documented the occurrence of metacercariae of Austrodiplostomum spp. (Diplostomidae) in the eyes and cranial cavity of H. malabaricus and described parasite-induced behavioral changes in the host. The fish were collected from the upper São Francisco River, in the Serra da Canastra mountain range, Minas Gerais, transported alive to the laboratory, observed for 2 weeks, and subsequently examined for parasites. Of the 35 fish examined, 28 (80 %) had free metacercariae in the vitreous humor (mean intensity=95.4; mean abundance=76.3), and 24 (68.57 %) had free metacercariae in the cranial cavity, mainly concentrated below the floor of the brain, at the height of the ophthalmic lobe (mean intensity=12.91; mean abundance=8.85). Specimens of H. malabaricus with a high intensity of infection in the brain displayed changes in swimming behavior.

The objective of the present study was to discover the hematological indices of Hoplias malabaricus infected by larvae of Contracaecum sp. A total of 105 fish were collected from two lakes located in the municipal district of Pirassununga, São Paulo, Brazil, of which 95.2% were infested by L3 larvae of Contracaecum sp., with an average intensity of 348.7 ± 231.55 helminths/fish. A total of 76 fish were analyzed to establish hematological parameters. Following analysis, it was found that there was a significant difference between hematological parameters Hct, erythrocytes (Er), thrombocytopenia (p = 0.01), and Hb (p = 0.02) in lakes A and B, while there was no significant difference for leukocyte (p = 0.68), mean corpuscular volume, mean corpuscular hemoglobin (p = 0.06), and mean corpuscular hemoglobin concentration (p = 0.47). The intensity of infection correlated negatively with Er (r(s) = -0.42; p < 0.01) and positively for (r(s) = 0.48; p < 0.01). The high intensity of infection by Contracaecum sp. in H. malabaricus did not affect the health of the fish despite causing alterations in hematological variables.

This study describes the hematological alterations in Astyanax altiparanae associated with infestation with Lernaea cyprinacea. The study was carried out in a lagoon of the MogiGuaçu River, in the municipality of Pirassununga, in the state of São Paulo, Brazil. Of 46 fish examined, 45.6% had their integument infested by L. cyprinacea, with a mean intensity of 4.9 parasites per fish and a mean abundance of 2.2, giving a total of 139 recovered crustaceans. The abundance of L. cyprinacea correlated positively with the length and weight of the hosts, and the intensity of infestation was higher in female hosts. Macroscopic observation of lesions associated with the parasite showed a severe inflammatory reaction around the site of attachment of L. cyprinacea, associated with a lower relative condition factor and blood parameters. The hematocrit, number of red blood cells and thrombocytes were higher in non-parasitized than in parasitized fish. However, the hemoglobin concentration, hematimetric indices and the number of white blood cells were not influenced by infestation. KEY WORDS: Ectoparasites · Hematology · Infestation · Continental fish Resale or republication not permitted without written consent of the publisherDis Aquat Org 120: [77][78][79][80][81] 2016 Gallio et al. , Raissy et al. 2013). Often such damage can lead to secondary infections caused by bacteria and fungi in hosts (Gabrielli & Orsi 2000, Thatcher 2006, Gallio et al. 2007, Raissy et al. 2013. Heavy infestations may cause mass mortalities of wild and farmed fish and make the fish undesirable to anglers, thus affecting fishery management targets (Thatcher 2006, Raissy et al. 2013. L. cyprinacea was introduced to Brazil along with carps imported from Hungary, and presently these parasites can be found infesting diverse wild fish populations in various hydrographic basins of the country (Medeiros & Maltchik 1999, Gabrielli & Orsi 2000, Gallio et al. 2007).In fish populations, blood parameters can be important tools for understanding the physiology and oxygen carrying capacity, as well as the immune system, of fish , Ranzani-Paiva et al. 2013. Therefore, blood cell parameters may be good indicators of the health status of a fish population (Nair & Nair 1983, Ranzani-Paiva et al. 2013. However, few studies have addressed the effects of the infestation of parasitic crustaceans on the hematological parameters of fish (Nair & Nair 1983, Silva-Souza et al. 2000, TavaresDias et al. 2007, Fajer-Ávila et al. 2011, Peña-Rehbein et al. 2013). This study investigated the effect of moderate levels of infection by L. cyprinacea on the hemato logical parameters of A. altiparanae from the Mogi-Guaçu River, part of the upper Pa raná River basin (Brazil). MATERIALS AND METHODSIn August 2012, 46 specimens of Astyanax altiparanae were caught in a lagoon of the Mogi-Guaçu River, in the municipality of Pirassununga, in the state of Sao Paulo, Brazil (21°55' 55'' S, 47°22' 37'' W) (Fig. 1). Fish were caught with gillnets of different meshes (5, 10 and 12 mm) ...

The present study describes Trypanosoma spp. infection and blood parameters in Pterygoplichthys pardalis from the Tapajós River basin in eastern Amazon (Brazil). Of 32 fi sh examined, 40.6% were infected by Trypanosoma spp., while a total of 112 trypomastigotes were found. Two Trypanosoma morphotypes were characterized and compared with species described in literature infecting other Loricariidae, and a similarity of 94% was found with one species described for another host. The plasma glucose and aspartate aminotransferase levels, hematocrit, number of total erythrocytes, mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) in the infected and uninfected fi sh were similar, but hemoglobin was lower in fi sh infected with Trypanosoma spp. Hemoglobin levels declined with the abundance of the hemoparasites, but the condition factor was similar among fi sh infected and uninfected by Trypanosoma spp. This is the fi rst study on the hemoparasitism by Trypanosoma spp. and blood parameters in P. pardalis.

SummaryHoplias malabaricus and Hoplerythrinus unitaeniatus are Erythrinidae family widely distributed in the Amazon River system of great value to both commercial and subsistence fishing for riverine populations. As such, the objective of the present study was to investigate the endoparasite communities of H. malabaricus and H. unitaeniatus of a tributary of the Amazon River in the north of Brazil. The endoparasite communities of H. unitaeniatus and H. malabaricus were taxonomically similar (85%) and consisted of Clinostomum marginatum, Contracaecum sp., Guyanema seriei seriei, Procamallanus (Spirocamallanus) inopinatus, Pseudoproleptus sp. and Gorytocephalus spectabilis, although the dominant endoparasite was C. marginatum, which was the most prevalent and abundant. All the specimens of both H. malabaricus and H. unitaeniatus were parasitized, with a total of 1237 helminths collected in the former host and 1151 helminths collected in the latter. Hoplerythrinus unitaeniatus possessed greater parasite species richness. Both hosts had an aggregate dispersion of parasites, and the abundance of C. marginatum, Contracaecum sp. and G. spectabilis correlated positively with the weight and length of the hosts. The condition factor was not affected by parasitism, but the abundance of C. marginatum and Contracaecum sp. increased when the condition factor of the hosts decreased. This is the first report of G. seriei seriei for H. malabaricus and Pseudoproleptus sp. for H. unitaeniatus.