Navegando por Assunto "Parasitos"

Agora exibindo 1 - 17 de 17

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Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae)
(Universidade Federal do Pará, 2016-03) MACEDO, Lilian Cristina; MELO, Francisco Tiago de Vasconcelos; ÁVILA-PIRES, Teresa Cristina Sauer de; GIESE, Elane Guerreiro; SANTOS, Jeannie Nascimento dos
Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the “Osvaldo Rodrigues da Cunha” Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.
Acesso aberto (Open Access)
Aspectos anatomopatológicos em cães naturalmente infectados por Hepatozoon canis
(Universidade Federal do Pará, 2017-02) LIMA, Pâmela Aparecida de; BARÇANTE, Joziana Muniz de Paiva; BOELONI, Jankerle Neves; BEZERRA JÚNIOR, Pedro Soares; WOUTERS, Flademir; WOUTERS, Angelica Terezinha Barth; VARASCHIN, Mary Suzan; SEIXAS, Josilene Nascimento
Canine hepatozoonosis is mainly caused by protozoa Hepatozoon canis and H. americanum that are transmitted by ingestion of infected ticks. Clinical signs may be unspecific or difficult to identify, because usually hepatozoonosis occurs associated with other disease. In Brazil, the parasite and the disease, have been identified in several states, however little is known about the clinical and anatomopathological lesions resulting from the infection. This paper reports five cases of natural infection by Hepatozoon canis in dogs from Minas Gerais State and describes for the first time in Brazil the necropsy and histopathological findings related to infection. Meronts of Hepatozoon sp., submitted to morphometric evaluation, were observed in histological sections of liver, spleen, bone marrow and kidney.
Acesso aberto (Open Access)
Diversidade de helmintos parasitos de uma população de Osteocephalus cabrerai (Anura: Hylidae) na Amazônia brasileira
(Universidade Federal do Pará, 2024-10) NEVES, Jorge Kevin da Silva; MELO, Francisco Tiago de Vasconcelos; http://lattes.cnpq.br/8939740618818787; https://orcid.org/0000-0001-8935-2923
Amphibians are good models for studies of parasite diversity due to their wide range of life strategies, standing out as hosts for various groups of nematodes, trematodes, cestodes, monogeneans, and acanthocephalans. The structure of parasitic communities in anurans can be influenced by various biotic or abiotic factors. Despite being extensively studied, the taxa found are rarely identified to the species level. To date, no parasitological studies have been conducted on representatives of Osteocephalus cabrerai, leaving the parasitic fauna of these anurans completely unknown. This study aims to characterize the diversity of parasitic helminths of O. cabrerai from the Beija-Flor Brilho de Fogo Extractive Reserve. This thesis comprises two chapters. The first chapter consists of a published Research Article that presents the first records of parasites for O. cabrerai, analyzing the composition and characteristics of the parasitic community, patterns of parasite distribution, and the correlation between host biotic factors and the characteristics of the community. We predominantly found nematodes with a monoxenous life cycle, high prevalence, and abundant infection. Most specimens represent the first record of parasites for the genus Osteocephalus. Additionally, in our analyses, individuals with greater body mass tended to have higher susceptibility to parasitic helminth infections. The second chapter presents a Short Communication with the first molecular and phylogenetic analyses involving A. pella, concluding that the genus Aplectana is not monophyletic. We provide the first study on the helminth community structure of O. cabrerai and add the first sequence of Aplectana from the Neotropical region. Thus, we enhance the understanding of the diversity and ecology of parasitic helminths in anurans, as well as the phylogenetic relationships of species within the family Cosmocercidae.
Acesso aberto (Open Access)
Effects of chromium supplementation on the infrapopulations of Anacanthorus penilabiatus (Monogenoidea) and Piscinoodinium pillulare (Dinoflagellida) parasites of Piaractus mesopotamicus (Characidae)
(2010-08) FUJIMOTO, Rodrigo Yudi; CASTRO, Marcello Pardi de; MARTINS, Maurício Laterça; MORAES, Flávio Ruas de; VARELLA, Jamille Elzira de Almeida; DINIZ, Daniel Guerreiro
This study evaluated the parasitism by Anacanthorus penilabiatus (Monogenoidea) and Piscinoodinium pillulare (Dinoflagellida) in the gills of "pacu", Piaractus mesopotamicus supplemented with chromium in the diet. Randomised delineation by using factorial scheme (4x2x2) for Monogenoidea and 4x2x3 for Dinoflagellate with four levels of chromium (0, 6, 12, 18mg/kg diet), two stocking densities (4kg/m3 and 20kg/m3), two classes of length (higher and lower than 17 cm) for a period of 7, 60 and 90 days, and four replicates was used. The fishes in low density which received 12 and 18mg/kg showed decreased monogeneoidea values, seven days after the experiment begin. Six, 12 and 18 mg/kg caused reduction in the dinoflagellate number in the fishes maintained at 20kg/m3. It was possible that chromium supplementation (12 e 18mg/kg) favoured the fishes health by reducing Monogenoidea and Dinoflagellida number in lower and higher densities, respectively.
Acesso aberto (Open Access)
Estrutura da comunidade de helmintos parasitos de Bothrops atrox (Linnaeus, 1758) (Serpentes: Viperidae) da Amazônia Oriental brasileira
(Universidade Federal do Pará, 2025-05) MOURA, Fred Gabriel Haick de; MELO, Francisco Tiago de Vasconcelos; http://lattes.cnpq.br/8939740618818787; HTTPS://ORCID.ORG/0000-0001-8935-2923; MASCHIO, Gleomar Fabiano; http://lattes.cnpq.br/7967540224850999; https://orcid.org/0000-0002-9013-4437
Snakes play an important role in the life cycles of a wide variety of parasitic helminths, acting as both definitive and intermediate hosts. Several factors can influence the diversity, composition, and structure of parasite communities associated with these reptiles. Bothrops atrox, a venomous snake belonging to the family Viperidae and widely distributed throughout the Amazon, is of great medical relevance. Despite having a relatively well-documented helminth fauna, gaps remain in our understanding of the parasite-host dynamics involving this species. Therefore, the objective of this study was to analyze the diversity and structure of the helminth community of B. atrox in two localities within the Brazilian Amazon. This dissertation is structured into two chapters. In the first, we present results from a comparative analysis of the helminth community structure in B. atrox from two contrasting Amazonian environments: ombrophilous forest and natural open fields. Our analyses revealed a higher abundance of parasites in hosts from forested areas, and a positive correlation between host body size and parasite abundance. This is the first study specifically dedicated to investigating the diversity and structure of helminth communities in B. atrox across different ecosystems. In the second chapter, we describe a new species of the genus Kalicephalus, based on morphological characteristics and molecular data. This species showed the highest levels of abundance, dominance, and prevalence in forest communities. The chapter also brings new insights into the evolutionary history of the genus, contributing to a better understanding of its diversity and evolution. Thus, our study provides new data for understanding the diversity and ecology of helminth parasites of snakes in the Amazon.
Acesso aberto (Open Access)
Estudo morfológico de microparasitas em Aequidens plagiozonatus Kullander 1984 (Osteiththyes: Cichlidae)
(Universidade Federal do Pará, 2010-12-22) VIDEIRA, Marcela Nunes; MATOS, Edilson Rodrigues; http://lattes.cnpq.br/7895814591867510
The ornamental fish market has been growing gradually in recent years and the increasing pressure on the banks of natural fishery resources, seeks to find alternatives to the continued production of fish through aquaculture or is the search for new features or even slightly, such as fish Aequidens plagiozonatus, common name cará pixuna. Based on this knowledge is important to perform studies characterizing the parasitological profile of these species of fish in order to verify and control the spread of parasites that cause imbalance in aquatic ecosystems. The objective this study was to provide a better understanding the bioecology, through a survey of actions caused by parasitic microparasites (microsporídios, myxosporídios e coccidios) emphasizing the morphology of these organisms. For this, five collections were made, totaling 100 specimens, which were autopsied and having their organs. Parasitized organs were removed fragments, fixed and processed for light microscopy. Hepatosomatic index were calculated and the prevalence of the parasite specimens for each group of parasites analyzed, giving the enfaze microparasites. From the observations made were 3 phyla were found: Myxozoa, Microsporidia and Apicomplexa. We observed the first occurrence of mixosporidiose urinary bladder of this species. We also observed the occurrence of multiparasitism and the multifocal localization of some parasites. The prevalence of microsporidia in the studied was 100%, 18% myxosporeans, Apicomplexa 45%. These data represent an important contribution to the study sanitary fish A. plagiozonatus in the region, since any activity that involves the extraction of natural resources should be managed through planning and management measures to allow the equilibrium of ecosystems, promoting sustainable use of its resources and guaranteeing the preservation of the system, so that it can prevent the spread and transfer of disease by means of aquatic animals. Keywords: Fish, Ictioparasitology, Aequidens plagiozonatus, microparasites.
Acesso aberto (Open Access)
Experimental infection in Notodiaptomus sp. (Crustacea: Calanoida) with larvae of Camallanus sp. (Nematoda: Camallanidae)
(2007-04) MARTINS, Maurício Laterça; GHIRALDELLI, Luciana; GARCIA, Fabiana; ONAKA, Eduardo Makoto; FUJIMOTO, Rodrigo Yudi
This trial registered the experimental infection viability with nematode larvae Camallanus sp. in Notodiaptomus sp., a crustacean, which can be an intermediate host. Adult females of nematode were dissected from the intestines of Xiphophorus maculatus (Osteichthyes: Poeciliidae), at a fish farm in the State of São Paulo. Females were slightly compressed for larvae release, collected with Pasteur pipette and separated on Petri dishes with 9ml filtered water at 28.1ºC, from zooplankton culture. Treatments consisted of Petri dishes with 60 and 105 copepods, in which 120, 150 and 210 larvae of nematode were added in four replications. Twenty-four and 36h after exposition to the larvae, the copepods were fixed in 70% alcohol to record the amount of fixed larvae. Twenty four hours after exposition, 60 copepods group with 120 larvae showed significantly higher prevalence (46.5%) when compared to 105 copepods and 120 larvae (33.2%). Thus, these answers suggested that 120 larvae were enough for a successful infectivity. Experimental infection was available and so, it was used as a pattern to life cycle studies of camallanid nematodes and hosts susceptibility tests.
Acesso aberto (Open Access)
Fauna microparasitária de Brachyplatystoma rousseauxii e Mugil curema desembarcados na Amazônia oriental
(Universidade Federal do Pará, 2013-11-29) DIAS, Lilian de Nazaré Santos; MATOS, Edilson Rodrigues; http://lattes.cnpq.br/7895814591867510; PAIVA, Rosildo Santos; http://lattes.cnpq.br/0510818763187669; FREITAS, José de Arimatéa; http://lattes.cnpq.br/2382745365421156
The gilthead bream Brachyplatystoma rousseauxii and white mullet Mugil curema are species of fish consumption and considerable commercial value found in estuarine cost of Pará The microparasites phyla Apicomplexa, Microspora and Myxozoa are organisms that can be found parasitizing vertebrates and invertebrates, including the fish, some pathogenic potential and even zoonotic and economic impact. To discover the fauna microparasites affecting fish , 62 specimens of B. rousseauxii and 58 M. curema estuarna captured on the coast of the city of Vigia de Nazare and Mosqueiro District, in Belem, Para state were examined as methods and techniques for morphological analysis (microscopy light), ultrastructural (transmission electron microscopy, TEM) and molecular biology (phylogenetic analysis). It was observed that there are three phyla (three in B. rousseauxii and two in M. curema) captured hosts in the two locations , plus the largest parasitic index was determined in specimens of both captured on the coast of the estuarine Vigia de Nazare , higher incidence of co microparasites phyla Apicomplexa and Myxozoa, beyond multiparasitism in B. rousseauxii Morphological analysis revealed the presence of Calyptospora sp. (Apicomplexa), Ellipsomyxa sp., Henneguya sp., Myxobolus sp. and Meglishcha sp. (Myxozoa) and Kabatana sp. (Microspora) in B. rousseauxii and Ellipsomyxa sp., Myxobolus sp. and Microspora phylum microparasito in M. curema. The data analysis of morphological and ultrastructural Myxospora found in B. rousseauxii and M. curema are suggestive of new species microparasites these two hosts. Phylogenetic analysis of the data did not provide results that allow the classification of Kabatana sp. (Microspora) and Henneguya sp. (Myxozoa) found parasitizing B. rousseauxii microparasites as new species in this host due to low bootstrap value, but by analyzing the distance p was possible to suggest that these are new species. Studies about microparasites in Amazonian fish are needed for the knowledge of the occurrences, characterization d new species, the pathogenic potential hosts and possible risk to the consumer.
Acesso aberto (Open Access)
Frequência e diversidade de enteroparasitos veiculados por hortaliças comercializadas na cidade de Belém-PA e sua relação com a sazonalidade climática
(Universidade Federal do Pará, 2010) BORGES, Samuel da Luz; BATISTA, Evander de Jesus Oliveira; http://lattes.cnpq.br/2206444845201080
The intestinal parasites are an important healthy problem to human population worldwide. The consumption of vegetables is one of the major routes of transmission of this pathogens. This study aimed to determine the frequency and diversity of intestinal parasites transmitted by vegetables sold in the metropolitan region of Belém-PA and its relation to the seasonal climate of the region. It was used 252 samples of three species of vegetables, of which 84 were of lettuce (Lactuca sativacurly variety), 84 were watercress (Nasturtium officinale) and 84 were coriander (Coriandrum sativum) purchased in open markets, gardens and in a supermarket, from November of 2008 to December of 2009. Each samples was washed with 500ml of PBS, permitting the spontaneous sedimentation and centrifuging 30 ml of the final sediment. The final sediment was analyzed in an optical microscope. The levels of contamination of the three species of vegetables were obtained by the monthly average of intestinal parasite structures identified in each vegetable and by the total number of parasites identified in the samples of each open market, garden and supermarket. In the results obtained in the microscopic analysis of samples were applied the Chi-square and Fisher's Exact Test to determine the existence or not of significant differences between these results. It was used the significance level α ≤ 0.05. This microscopic analysis showed a contamination of 100% of the samples at open markets, gardens and supermarket included in the study, there isn’t statistical difference in overall frequency of parasites among them. Strongyloides stercoralis was the most prevalent parasite, followed by complex Entamoeba histolytic / dispar and the hookworms, both in samples from the gardens, as in samples of the open markets and the supermarket. The cress and lettuce had higher rates of parasitic contamination that coriander. It had been characterized seasonal influence on the intensity of parasites in vegetables investigated because there was statistical difference between the results obtained with a higher prevalence of parasites in samples of summer, for the samples of winter. There wasn’t also statistically significant difference between the monthly averages of contamination of vegetables sold in open markets, gardens and supermarket, indicating that the hygienic conditions under which the vegetables are sold, although important to keep their flavors, have less influence on levels of parasitic contamination, which seems to be associated with the place and growing conditions these plants. These datas permit a good level of comparison to future studies.
Acesso aberto (Open Access)
Gobioides broussonnetii (Gobiidae): a new host for Pterobothrium crassicolle (Trypanorhyncha) on Marajó Island, northern Brazil
(2013-09) VIDEIRA, Marcela Nunes; SILVA, Michele Velasco Oliveira da; DIAS, Lilian de Nazaré Santos; MATOS, Patrícia Santos; ALMEIDA, Henrique Diniz Ferreira de; COSTA, Marcondes Lima da; SÃO CLEMENTE, Sérgio Carmona de; MATOS, Edilson Rodrigues
In the present study, the cestoid Pterobothrium crassicolle Diesing, 1850 (Trypanorhyncha), was observed parasitizing specimens of the violet goby (Gobioides broussonnetii Lacepède, 1800) collected from the estuary of the Paracauarí River on Marajó Island in the north of the Brazilian state of Pará, between January 2009 and December 2010. Tissue samples were analyzed, which led to identification of blastocysts containing plerocercoid larvae. These larvae were processed for scanning electron microscopy. Sixty G. broussonnetii specimens were dissected, and P. crassicolle was found in 48 (80%) of them. The violet goby, G. broussonnetii, is a new host for P. crassicolle.
Acesso aberto (Open Access)
Infestation by Haematopinus quadripertusus on cattle in São Domingos do Capim, state of Pará, Brazil
(Universidade Federal do Pará, 2012-09) SCOFIELD, Alessandra; CAMPOS, Karinny Ferreira; SILVA, Aryane Maximina Melo da; OLIVEIRA, Cairo Henrique Sousa de; BARBOSA NETO, José Diomedes; CAVALCANTE, Gustavo Góes
Severe infestation with lice was observed on crossbred cattle (Bos taurus indicus × Bos taurus taurus) in the municipality of São Domingos do Capim, state of Pará, Brazil. Sixty-five animals were inspected and the lice were manually collected, preserved in 70% alcohol and taken to the Animal Parasitology Laboratory, School of Veterinary Medicine, Federal University of Pará, Brazil, for identification. The adult lice were identified as Haematopinus quadripertusus, and all the cattle examined were infested by at least one development stage of this ectoparasite. The specimens collected were located only on the tail in 80% (52/65) of the cattle, while they were around the eyes as well as on the ears and tail in 20% (13/65). Nits, nymphs and adults of the parasite were respectively collected from 98.46% (64/65), 38.46% (25/65) and 23.08% (15/65) of the animals examined. This is the first report of bovine pediculosis caused by H. quadripertusus in the state of Pará, Brazil. Further studies should be conducted to determine the occurrence pattern of this species in Brazil and its importance to livestock production.
Acesso aberto (Open Access)
Light and electron microscopy of Myxobolus sciades n. sp. (Myxozoa), a parasite of the gills of the Brazilian fish Sciades herzbergii (Block, 1794) (Teleostei: Ariidae)
(2010-03) AZEVEDO, Carlos José Correia de; CASAL, Graça Maria Figueiredo; MENDONÇA, Ivete Lopes de; CARVALHO, Erisson; MATOS, Patrícia Santos; MATOS, Edilson Rodrigues
A myxosporean parasite in the gill lamellae of the freshwater teleost fish, Sciades herzbergii (Ariidae) (Block, 1794), from the Poti River (Northeast of Brazil) was described by light and electron microscopy studies. Polysporic histozoic cyst-like plasmodia containing several life-cycle stages, including mature spores, were observed. The spores were pyriform and uninucleate, measuring 9.15 ± 0.39 μm (n = 50) long, 4.36 ± 0.23 μm (n = 25) wide and 2.61 ± 0.31 μm (n = 25) thick. Elongated pyriform polar capsules (PC) were of equal size (4.44 ± 0.41 μm long and 1.41 ± 0.42 μm in diameter) and each contained a polar filament with 9-10 coils obliquely arranged in relation to the axis of PC. The PC wall was composed of two layers of different electron densities. Histological analysis revealed the close contact of the cyst-like plasmodia with the basal portion of the epithelial gill layer, which exhibited some alterations in the capillary vessels. Based on the morphological and ultrastructural differences, the similarity of the spore features to those of the genus Myxobolus and the specificity of this host to previously described species, we describe a new species named Myxobolus sciades n. sp. in this study.
Acesso aberto (Open Access)
Myxidium volitans sp. nov., a parasite of the gallbladder of the fish, Dactylopterus volitans (Teleostei: Triglidae) from the Brazilian Atlantic coast: morphology and pathology
(2011-08) AZEVEDO, Carlos José Correia de; CASAL, Graça Maria Figueiredo; SÃO CLEMENTE, Sérgio Carmona de; LOPES, Leila Maria Silva; MATOS, Patrícia Santos; ABDEL-BAKI, Abdel Azeem; OLIVEIRA, Elsa; MATOS, Edilson Rodrigues
Myxidium volitans sp. nov. (Myxozoa: Myxidiidae) parasitizing the hypertrophied green-brownish gallbladder of the teleost Dactylopterus volitans, collected in the Atlantic coast near Niterói, Brazil was described based on ultrastructural studies. The spores were fusiform, sometimes slightly crescent-shaped on average 21.7 ± 0.3 µm (mean ± standard deviation) (n = 50) long and 5.6 ± 0.4 µm (n = 30) wide. The spore wall was thin and smooth, comprising two equally-sized valves joined by a hardly visible sutural ridge. Spores containing two pyriform polar capsules (PC) (5.0 ± 0.4 × 2.3 ± 0.3 µm) (n = 30) are situated in each extremity of the spore. The PC wall was composed of hyaline layer (0.20-0.29 µm thick) and by a thin external granular layer. Each PC contains a polar filament (PF) with irregular arrangements that was projected from its apical region to the bases of PC and coiled laterally from bases to the tip of PC. Some regular striations and S-like structures in the periphery of the PFs with four-five irregular sections were observed. Based on the spore morphology, ultrastructural differences and the specificity of the host we describe this parasite as a new myxosporidian, named M. volitans sp. nov.
Acesso aberto (Open Access)
A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda) on fishes from Northeast of Pará, Brazil
(2008-12) DINIZ, Daniel Guerreiro; VARELLA, Jamille Elzira de Almeida; HOSHINO, Maria Danielle Figueiredo Guimarães; SANTOS, Arthur Felipe Lima dos; FUJIMOTO, Rodrigo Yudi; MONFORT, Karla Cibele Fragoso; PIRES, Marcus Alexandre Borges; MARTINS, Maurício Laterça; EIRAS, Jorge Costa
The infection of the estuarine teleost fishes Mugil gaimardianus Desmarest, 1831 (Mugilidae), Arius phrygiatus Valenciennes, 1839 (Ariidae), Conodon nobilis Linnaeus, 1759 (Haemulidae), Cetengraulis edentulus Cuvier, 1829 (Engraulidae), and Anableps anableps Linnaeus, 1758 (Anablepidae) by praniza larvae of Gnathiidae (Crustacea, Isopoda) was studied in specimens fished off the Atlantic Ocean in Northeast of Pará State, near Bragança, Brazil. The highest infection prevalence value was found in Anableps anableps (42.3%) and the lowest in Conodon nobilis (9.1%). The mean intensity varied from 1 parasitein Conodon nobilis to 19.5 in Arius phrygiatus. A description of the larvae is provided. The morphology of the mouthparts is related to the blood sucking activity, and is compared with the characteristics of other gnathiidae species.
Acesso aberto (Open Access)
Pesque-solte: pesca repetitiva, variáveis hematológicas e parasitismo no peixe híbrido tambacu
(2013-08) VARANDAS, Daniela Nomura; MARTINS, Maurício Laterça; MORAES, Flávio Ruas de; RAMOS, Fabrício Menezes; SANTOS, Rudã Fernandes Brandão; FUJIMOTO, Rodrigo Yudi
The objective of this work was to evaluate the hematological and parasitological responses of tambacu (Colossoma macropomum x Piaractus mesopotamicus) subjected to catch-and-release stress and to different stocking densities in a catch-and-release system. Two hundred and ten fish with mean initial weight of 785.33±152.02 g and mean total length of 34.43±2.21 cm were maintained in ponds and divided into three groups: without fishing and low density (G1), with fishing and low density (G2), and with fishing and high density (G3). No significant differences were observed between the mean values for hemoglobin concentration, erythrocyte number, differential counting of leukocytes, and glucose. The fish from the G3 group showed higher parasite and thrombocyte numbers, and lower weight gain and hematocrit. The activity of catch-and-release, associated with high stocking density, can disrupt organic balance and animal performance, favoring parasitosis.
Acesso aberto (Open Access)
Protozoan parasites of Xiphophorus spp. (Poeciliidae) and their relation with water characteristics
(2009-02) GARCIA, Fabiana; FUJIMOTO, Rodrigo Yudi; MARTINS, Maurício Laterça; MORAES, Flávio Ruas de
This work investigated the relationship between water characteristics and infestation of protozoan parasites, Icthyophthirius multifiliis and Trichodina sp., in swordtails (Xiphophorus helleri) and platy (Xiphophorus maculates) collected in an ornamental fish farm in São Paulo, Brazil. Fish were monthly collected from ponds and tanks for one year. The prevalence rates in fish from tanks and ponds were, respectively, 34.2% and 22.5% for I. multifiliis, and 13% and 54.2% for Trichodina sp. Increased electric conductivity and pH provoked reduction of I. multifiliis infestation. Low oxygen concentration increased Trichodina sp. infestation. The use of salt to increase the electric conductivity of water was a method to control I. multifiliis. Low dissolved oxygen and the addition of organic fertilizer favored the reproduction of Trichodina sp.
Acesso aberto (Open Access)
Ultrastructural description of Ceratomyxa microlepis sp. nov. (Phylum Myxozoa): a parasite infecting the gall bladder of Hemiodus microlepis, a freshwater teleost from the Amazon River
(2013-04) AZEVEDO, Carlos José Correia de; ROCHA, Sonia Maria Rodrigues da; CASAL, Graça Maria Figueiredo; SÃO CLEMENTE, Sérgio Carmona de; MATOS, Patrícia Santos; AL-QURAISHY, Saleh; MATOS, Edilson Rodrigues
A new ceratomyxid parasite was examined for taxonomic identification, upon being found infecting the gall bladder of Hemiodus microlepis (Teleostei: Hemiodontidae), a freshwater teleost collected from the Amazon River, Brazil. Light and transmission electron microscopy revealed elongated crescent-shaped spores constituted by two asymmetrical shell valves united along a straight sutural line, each possessing a lateral projection. The spores body measured 5.2 ± 0.4 µm (n = 25) in length and 35.5 ± 0.9 µm (n = 25) in total thickness. The lateral projections were asymmetric, one measuring 18.1 ± 0.5 µm (n = 25) in thickness and the other measuring 17.5 ± 0.5 µm (n = 25) in thickness. Two equal-sized subspherical polar capsules measuring 2.2 ± 0.3 µm in diameter were located at the same level, each possessing a polar filament with 5-6 coils. The sporoplasm was binucleate. Considering the morphometric data analyzed from the microscopic observations, as well as the host species and its geographical location, this paper describes a new myxosporean species, herein named Ceratomyxa microlepis sp. nov.; therefore representing the first description of a freshwater ceratomyxid from the South American region.