Identificação morfológica de organismos semelhantes à anaplasmataceae em monócitos de surubim híbrido (Pseudoplatystoma reticulatum x P. corruscans) – relato de caso

The aim of this study was to report the occurrence of Anaplasmataceae-like organisms in monocytes from the hybrid surubim catfish. During the hematological evaluation of fish infected by Pseudomonas sp. in a fish farm located in the State of Mato Grosso do Sul we observed into the monocytes the presence of numerous pleomorphic inclusions of various sizes, rough in appearance which presented basophilic staining. These inclusions were similar to elementary bodies, initial bodies and morule of the bacteria from Anaplasmataceae family, often diagnosed in domestic mammals. This is the first report of its occurrence possibly belonging to the family of Anaplasmataceae in cultured fish in Brazil. Additional studies are necessary for molecular characterization of this bacteria, pathogenic potential, life cycle and impact on the intensive production of fish.Este trabalho tem por objetivo relatar a ocorrência de organismos semelhantes à Anaplasmataceae em monócitos de surubim híbridos. Durante a avaliação hematológica em peixes infectados por Pseudomonas sp., num evento natural, nos peixes cultivados no Estado de Mato Grosso do Sul, verificou-se a presença de várias inclusões pleomórficas, exibindo aparência rugosa e coloração predominantemente basofílica, apresentando-se em monócitos de apenas um indivíduo de surubim híbrido. Estas inclusões são similares aos corpúsculos elementares, corpos inicias e mórulas de bactérias pertencentes à família Anaplasmataceae. Estudos adicionais são necessários para caracterização molecular desta bactéria, bem como caracterização do potencial patogênico, ciclo de vida e impacto de sua ocorrência na produção intensiva de peixes e saúde pública

Trichodina heterodentata (Ciliophora: Trichodinidae): a new parasite for Piaractus mesopotamicus (Pisces: Characidae)

Trichodinids are mobile peritrichous ciliated protozoa, and widely known as ectocommensals and/or parasites of fish and other aquatic organisms. Little is known about the trichodinid fauna in Brazilian fish. This study reports Trichodina heterodentata Duncan, 1977 as a new parasite for freshwater fish Piaractus mesopotamicus Holmberg, 1887. This is the first record of this trichodinid in southeastern Brazil. Fifty specimens impregnated with 2% silver nitrate and another fifty stained with Giemsa were used for morphometry on the taxonomic characteristics. T. heterodentata in this study is medium size, with a disc-shaped body measuring 49.0 to 61.0 mu m, parasitizing the skin, fins and gills of pacu. Measurement comparisons between the present material and other records from different countries are presented.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Trichodina heterodentata (Ciliophora) infestation on Prochilodus lineatus larvae: a host-parasite relationship study

Prochilodus lineatus is a freshwater fish species found in South America. It is common in aquaculture, but few studies regarding diseases of this fish have been performed. This study presents data of the occurrence of Trichodina heterodentata Duncan, 1977, as well as the pathological alterations detected by light and scanning electron microscopy (SEM). Twenty 20-day-old larvae were harvested from an earth pond and examined. Larvae showed erratic swimming on the pond edges and some had a whitish tegument. Larval smears were either impregnated with silver nitrate or stained with Giemsa stain to observe the taxonomic features of the ciliates. Five larvae were fixed in formalin solution for histopathological analysis, and another five specimens were fixed in glutaraldehyde for SEM. All larvae were diagnosed with a severe infestation by trichodinid T. heterodentata. Histological sections showed discrete hyperplasia of the gill filaments with subepithelial oedema of the secondary lamellae. In the SEM, suction areas were observed on the skin, gill and eye; corrosion and ulceration of the fins were associated with the bacterial presence of cocci on the lesions. This is the first report of T. heterodentata in P. lineatus that is responsible for an acute disease that culminates in larval mortality.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Hematological parameters of Pimelodus maculates (Osteichthyes: Pimelodidae) from polluted and non-polluted sites in the Itajaí-Açu river, Santa Catarina State, Brazil - DOI: 10.4025/actascibiolsci.v31i2.3267

This study evaluated the hematological response of Pimelodus maculates captured in two environments with different levels of pollution in the Itajaí-Açu river, Santa Catarina State, southern Brazil. One of them, hereby named reference site, is a water captation site that supplies the city of Blumenau, in which the riparian forest is preserved and there is no sewage discharge. The other, denominated polluted site, is characterized by discharge of domestic sewage. After water quality analysis, fish were captured, transported to the laboratory and anesthetized for the hematological exam. In the polluted site, the most probable number of fecal coliforms and water transparency were respectively higher and lower than that observed at the reference site. The main results were an increased percentage of hematocrit and reduced numbers of lymphocytes and monocytes in the differential counting in fish from the polluted site. Red blood cells, total white blood cells and total counting of thrombocytes did not vary between environments. The number of neutrophils remained at high levels in fish from both environments. This study demonstrated that water quality might affect the hematological parameters in free-living fish.This study evaluated the hematological response of Pimelodus maculates captured in two environments with different levels of pollution in the Itajaí-Açu river, Santa Catarina State, southern Brazil. One of them, hereby named reference site, is a water captation site that supplies the city of Blumenau, in which the riparian forest is preserved and there is no sewage discharge. The other, denominated polluted site, is characterized by discharge of domestic sewage. After water quality analysis, fish were captured, transported to the laboratory and anesthetized for the hematological exam. In the polluted site, the most probable number of fecal coliforms and water transparency were respectively higher and lower than that observed at the reference site. The main results were an increased percentage of hematocrit and reduced numbers of lymphocytes and monocytes in the differential counting in fish from the polluted site. Red blood cells, total white blood cells and total counting of thrombocytes did not vary between environments. The number of neutrophils remained at high levels in fish from both environments. This study demonstrated that water quality might affect the hematological parameters in free-living fish

First report of Myxobolus sp infection in the skeletal muscle of Neotropical freshwater fish Piaractus mesopotamicus

Although there are several reports of Myxobolus species infecting the somatic muscle of teleost fish, species of this genus have not been described parasitizing the muscle tissue of pacus, Piaractus mesopotamicus. This study presented the first report of natural infection by Myxobolus sp. in the skeletal muscle of pacus reared in intensive system. Twenty-one fish (+/- 142.2 g; +/- 23.1 cm) were captured (April 2013) from an intensive fish farm in So Paulo State, southeast Brazil. Spores of Myxobolus sp. were contained within plasmodia and showed oval morphology with the apical portion slightly pyriform and two polar capsules pyriform retaining the same ratio to each other. In the histopathological study, the skeletal muscle do not present signs of inflammation. The integrity of myofibrils within the infected fibers showed some degree of degeneration, with partial loss of myofibrillar details and striations. Spores were found infecting the skeletal muscle of 18 fish (85.7 %). Finally, the high prevalence of Myxobolus sp. infection in the skeletal muscle of P. mesopotamicus and the absence of macroscopic lesions in the muscle tissue indicate the necessity of more meticulous examinations during the health management in the rearing system and at slaughter of pacus to ensure best quality of meat.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq