Antimicrobial resistance profile of Aeromonas spp. isolated from asymptomatic Colossoma macropomum cultured in the Amazonas State, Brazil.

Bacterial diseases are important factors that limit productivity in aquaculture. To reduce negative economic impacts, fish farmers use antimicrobials, often indiscriminately, and this action has led to bacterial resistance to drugs. The objectives of this study were to isolate and identify the main putative pathogenic bacterial species in tambaqui (Colossoma macropomum), establish the profile of resistance to antimicrobials by the methods of disc diffusion, and determine the minimum inhibitory concentration (MIC) values. Two hundred and ninety asymptomatic fish were collected between March and November 2015 from ten fish farms in the Amazonas state (Brazil). Of the total strains recovered from tambaqui, seven were identified as Aeromonas spp. by sequencing the 16S rRNA gene. These seven isolates showed resistance to ampicillin, 28% to erythromycin, and 28% to sulfonamide. Additionally, the seven isolates showed a MIC higher than the range evaluated for amoxicillin, penicillin, novobiocin, tylosin tartrate, and clindamycin, and 85% showed resistance to erythromycin. The results of this study indicate the need to increase the awareness of fish farmers and, most importantly, the government, about the lack of drug regulations for use in aquaculture, and good management practices, so the indiscriminate prophylactic and systemic use of antimicrobials be inhibited.

Growth and survival of the native oyster Crassostrea gasar cultured under different stocking densities in two grow-out systems in tropical climate / [Crescimento e sobrevivência da ostra nativa Crassostrea gasar cultivada em diferentes densidades em dois sistemas em clima tropical]

Survival and growth of the native oyster Crassostrea gasar along the juvenile and adult phases were evaluated in three different stocking densities [low (D), medium (2D) and high (3D)] and in two grow-out systems (fixed and floating system). The fixed system consisted of a rack made with PVC, fixed from the bottom with wood sticks. The floating system consisted of floating bags suspended by a rack made with PVC and maintained submerged from the seawater surface by eight floats. Survival and shell height of oysters cultured after 30, 60 and 90 days were registered in each phase and in each grow-out system. Results showed that the grow-out system did not affect survival and growth of C. gasar in the juvenile and adult phases. The tested densities affected the survival of oysters cultured over time in both phases but did not affect oyster growth. At times analyzed, it was observed positive growth in juvenile oysters grow after 90 days of culture. However, in the adult phase, no growth was observed after 90 days of culture. Oyster yield was higher in the density 3D, in both juvenile and adult phases. These findings contributed to the development of the oyster C. gasar culture.(AU)

A sobrevivência e o crescimento da ostra nativa Crassostrea gasar nas fases juvenil e adulta foram avaliados sob três diferentes densidades de estocagem [baixa (D), média (2D) e alta (3D)] e dois sistemas de engorda (fixo e flutuante). O sistema fixo consistiu em uma mesa de PVC, fixada na parte inferior com varas de madeira. O sistema flutuante consistiu em travesseiros flutuantes suspensos por uma mesa de PVC e mantidas submersas da superfície da água do mar por oito flutuadores. Registraram-se sobrevivência e altura da concha de ostras cultivadas após 30, 60 e 90 dias, em cada fase (juvenil e adulta) e em cada sistema (fixo e flutuante). Os resultados mostraram que o sistema de engorda não afetou a sobrevivência e o crescimento de C. gasar nas fases juvenil e adulta. As densidades testadas afetaram a sobrevivência das ostras ao longo do tempo, em ambas as fases, mas não afetaram o crescimento em altura. Nos tempos analisados, ostras juvenis apresentaram crescimento após 90 dias de cultivo. Porém, na fase adulta, não foi observado crescimento após 90 dias de cultivo. A produção de ostras, foi maior na densidade 3D, nas fases juvenil e adulta. Os presentes achados contribuíram para o desenvolvimento do cultivo da ostra C. gasar.(AU)

Sanitary conditions of the Goliath grouper Epinephelus itajara in captivity on estuarine environment: case report / Condições sanitárias do mero Epinephelus itajara em cativeiro em ambiente estuarino: relato de caso

This study aimed to report the sanitary conditions through the hematological analysis of grouper E. itajara reared in captivity on estuarine conditions. Seven Goliath groupers (1,881.5±1,246.03g) were captured and kept in two tanks located on estuary. After 20 days, fish were collected for morphologic and hemato-physiologic evaluation. Two fish had clinical signs such as hemorrhagic spots and loss of scale due to agonistic behavior. Blood samples were collected, and the hematological parameters (biochemical, erythrogram and leukogram) were determined. Blood cells were characterized by their size, color and shape. Univariate statistic and principal components analysis were used to identify a hematological standard between fish with or without clinical signs. Four leukocyte types were found: lymphocyte, monocyte, neutrophil and basophil. Regardless of the clinical signs the cell morphology did not present any difference among the fish. However, there is a significant correlation between erythrocyte and lactate on fish with clinical signs. Thus, agonistics encountered among the fish is a stressing factor in captivity conditions making it necessary to have adequate management related to the size of fish and stocking density.(AU)

Este estudo avaliou as condições sanitárias do peixe mero E. itajara mantido sob cativeiro, em condições estuarinas, pelas análises hematológica e morfológica. Sete peixes (1.881,5±1.246,03g) foram capturados e mantidos em tanques localizados no estuário. Após 20 dias, os peixes foram coletados para avaliações morfológica e hematológica. Dois peixes tiveram sinais clínicos, como manchas hemorrágicas e perda de escamas devido ao comportamento agonístico entre os peixes. Amostras sanguíneas foram coletadas dos peixes anestesiados com auxílios de seringas umedecidas com EDTA 3%. Determinaram-se os parâmetros hematológicos (bioquímico, eritrograma e leucograma). Células sanguíneas foram caracterizadas por seu tamanho, cor e padrão. Estatística univariada e análises de componentes principais foram usadas para identificar um padrão hematológico entre os peixes com e sem sinais clínicos. Quatro tipos de leucócitos foram encontrados: linfócito, monócito, neutrófilo e basófilo. Os sinais clínicos não apresentaram diferença entre os peixes e a morfologia celular. Contudo, observou-se uma correlação entre os peixes com sinais clínicos e a quantidade de eritrócitos e lactato. Assim, encontros antagônicos entre os peixes são um fator estressante em condições de cativeiro, tornando-se necessário um manejo mais adequado relacionado ao tamanho dos indivíduos e à densidade de estocagem.(AU)

Fauna parasitária e relação parasito-hospedeiro de tambaquis criados na região do Baixo São Francisco, nordeste do Brasil / Parasitic fauna and parasite-host relationship of tambaqui reared in São Francisco river basin, Brazilian northeast

Este trabalho teve como objetivo avaliar a fauna parasitária de tambaquis na região do Baixo São Francisco-AL/SE-Brasil e correlacionar os índices de prevalência e intensidade média com fatores bióticos e abióticos. Foram coletados 252 espécimes para análise parasitológica de 10 pisciculturas. Os parasitos foram contabilizados, identificados, e determinaram-se os índices de prevalência e intensidade média, que foram correlacionados com fatores bióticos e abióticos. Dos peixes coletados, 65,5% estavam parasitados por pelo menos um táxon. Foram encontrados 10 táxons: Monogeneas, Ichthyophthirius multifiliis, tricodinídeos, Piscinoodinium pillulare, Ichthyobodo sp., Dolops carvalhoi, Lernaea cyprinacea, Procamallanus (Spirocamallanus) inopinatus, Henneguya sp. e Myxobolus sp. As maiores prevalências foram encontradas para Monogeneas (49,2%) e Myxobolus sp. (31,5%). Correlações negativas entre prevalência e fatores bióticos (peso e comprimento) foram observadas para Monogeneas (r2= -0,49; r2= -0,43), Myxobolus sp. (r²= -0,46; r²= -0,39) e Henneguya sp. (r²= -0,41; r²= -0,39). O fator abiótico temperatura apresentou correlação negativa com as prevalências de Lernaea cyprinacea (r= -0,39) e tricodinídeos (r= -0,33), enquanto a condutividade elétrica apresentou correlação positiva (r= 0,40) com a prevalência de tricodinídeos. Conclui-se que a fauna parasitária dos tambaquis cultivados na região do Baixo São Francisco é diversificada e com a carga parasitária dependente da qualidade de água e do estágio de desenvolvimento dos peixes.(AU)

This study investigated the parasitic fauna of tambaquis reared in lower Sao Francisco region-Al/SE-Brazil correlating parasitic indices to abiotic and biotic factors. A total of 252 specimens of tambaqui were collected in ten fish farms for parasitological analysis. The parasites were counted, identified and the parasitological indices were determined and correlated to biotic and abiotic factors. Of all collected fish, 65,5 % were parasitized by at least one taxon. Ten taxa were found: Monogeneans, Ichthyophthirius multifiliis, trichodinids Piscinoodinium pillulare, Ichthyobodo sp, Dolops carvalhoi, Lernaea cyprinacea, Procamallanus (Spirocamallanus) inopinatus, Henneguya sp. and Myxobolus sp. The higher prevalences were found to monogeneans (49.2%) and Myxobolus sp. (31.5%). Negative correlation of prevalence and biotic factor (weight and length) were observed to monogeneans (r 2 = -0.49, r 2 = -0.43), Myxobolus sp (r²= -0.46; r²= -0.39) and Henneguya sp (r²= -0.41; r²= -0.39). Abiotic factor of temperature presented a negative correlation to prevalence of Lernaea cyprinacea and trichodinids (r= -0.39 e r= -0.33, respectively) and the electric conductivity presented positive correlation to trichodinids (r= 0.40). It was concluded that parasitic fauna of tambaquis cultured in Lower São Francisco region is diversified and the parasitic load dependent on water parameters and fish growth.(AU)

Resposta hematológica do cascudo ornamental amazônico Peckoltia oligospila ao estresse de transporte / Hematological response of Amazonian ornamental Peckoltia oligospila subjected to stress by transportation

O objetivo deste trabalho foi avaliar as respostas hematológicas do acari-bola Peckoltia oligospila submetido ao estresse de transporte. Variações nos parâmetros de sangue foram analisadas às zero, seis, 24, 48, 72 e 96 horas após o transporte. Respostas ao estresse foram observadas entre zero e seis horas do transporte, mas a maioria dos parâmetros retornou aos valores basais em 24 horas. O tempo de zero hora (momento imediato após transporte) foi o mais crítico, com valores elevados de glicemia, eritrócitos e eritroblastos. Respostas secundárias tardias foram observadas para a proteína plasmática total, o volume corpuscular médio (VCM) e a hemoglobina corpuscular média (HCM) em seis horas após o transporte dos peixes, retornando aos valores basais após esse período. O número de leucócitos não sofreu alterações após o transporte. O estresse de transporte não comprometeu a fisiologia de P. oligospila, o que indica que esse peixe é resistente ao estresse se comparado com outras espécies. Porém, recomenda-se que não se realize qualquer outro procedimento estressante durante pelo menos 24 horas da recuperação dos peixes após transporte, para garantir a saúde e a sobrevivência dos animais transportados.(AU)

The objective of this work was to evaluate the hematological responses of bola-pleco (Peckoltia oligospila) undergoing the stress of transportation. Variations on blood parameters were analyzed at 0, 6, 24, 48, 72 and 96h after transportation. Responses to stress were detected from 0 to 6h after the transportation of fish, however, most parameters returned to baselines values within 24h of transportation. The moment of 0h was the most critical, presenting higher values of glycemia, erythroblasts and erythrocytes. Late secondary responses were observed to total plasmatic protein, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) at 6h, returning to baselines values after this time. Leukocyte number was not affected by stress of transportation. The stress by transportation was not severe to influence the health of P. oligospila, indicating that fish is resistant to stress if compared to other species. However, we recommended no stressful procedures for at least 24 hours for recovery, in order to ensure health and survival of fish.(AU)

Efficacy of Ocimum gratissimum essential oil against the monogenean Cichlidogyrus tilapiae gill parasite of Nile tilapia / Eficácia do óleo essencial de Ocimum gratissimum contra o monogenea Cichlidogyrus tilapiae parasita de brânquias de tilápia-do-nilo

The phythotherapy is an alternative to use of chemotherapeutical agents against monogenean infection. This study evaluated the anthelmintic activity of essential oil Ocimum gratissimum against monogenean Cichlidogyrus tilapiae as well as its acute toxicity in tilapia juveniles. The mean lethal concentration (LC50) and different concentrations of the essential oil, both in vitro and in vivo assays (short and long-term baths) were assessed. The LC50 was 40.70mg.L-1 and in the in vitro assay this concentration showed 80% efficacy at the last two hours and in the in vivo assay 65.87% efficacy in long-term bath. However, it provoked morphological alterations on the gills such as hyperplasia and edema. The parasites exposure at the highest concentration (320mg.L-1) showed 100% mortality after 2h exposure in the in vitro assay, whereas in the in vivo assay, short-term baths of 5min for 3 consecutive days showed an efficacy of 87.71% without gills damage. These results demonstrate the anthelminthic activity of essential oil O. gratissimum and the safety concentration to use in Nile tilapia.(AU)

A fitoterapia é uma alternativa ao uso de agentes químicos contra infecções por parasitos monogenéticos. Este estudo avaliou a atividade anti-helmíntica do óleo essencial Ocimum gratissimum contra o monogenea Cichlidogyrus tilapiae , bem como sua toxicidade aguda e histopatologia em juvenis de tilápias. Foram avaliadas a concentração letal média (CL50) e diferentes concentrações de óleo essencial, tanto in vitro como in vivo (banho de curta e longa duração). A CL50 foi de 40,70mg.L-1; no ensaio in vitro, essa concentração apresentou 80% de eficácia, e no ensaio in vivo 65,87% de eficácia em banho de exposição crônica. No entanto, provocou alterações morfológicas nas brânquias, como hiperplasia e edema. A exposição dos parasitas na concentração mais elevada (320mg.L-1) mostrou 100% de mortalidade após duas horas de exposição no ensaio in vitro, enquanto no ensaio in vivo, em banho de curta duração de cinco minutos, durante três dias consecutivos, apresentou uma eficácia de 87,71%, sem danos às brânquias. Esses resultados demonstraram a atividade anti-helmíntica do óleo essencial de O. gratissimum e a concentração de segurança para uso na tilápia-do-nilo em banhos de curta duração.(AU)

Anesthesia by sprinkling method in the gills of tambaqui Colossoma macropomum does not influence intensity and morphology of monogeneans / Anestesia por meio de aspersão nas brânquias de tambaqui Colossoma maropomum não influencia a intensidade e a morfologia de monogeneas

Abstract The present study evaluates the influence of anesthesia on the parasitic fauna of monogenea fish parasites, as its intensity and viability. Two experiments were conducted: Evaluation of an anesthetic method by sprinkling eugenol directly on gills and evaluation of monogenea motility and viability; Comparison of immersion and directly sprinkling on the gills with benzocaine and eugenol followed by evaluation on parasite intensity. The results suggest that the anesthetic sprinkling didn't interfere in the parasite motility, morphology and body surface integrity analyzed by fluorescence method. The monogenean intensity in the gills was lower in fish anesthetized by immersion method compared to the sprinkling method and the control group. This method of anesthesia can be used in parasitological studies.

Resumo O presente estudo avalia a influência da anestesia sobre a fauna parasitária de monogeneas em peixes, sua intensidade e sua viabilidade. Dois experimentos foram realizados: Avaliação de um método anestésico por aspersão eugenol diretamente nas brânquias e avaliação da motilidade das monogeneas e sua viabilidade; e Comparação entre imersão e aspersão diretamente nas brânquias com benzocaína e eugenol, seguido de avaliação sobre a intensidade parasitária. Os resultados sugerem que a aspersão do anestésico não interferiu na motilidade, morfologia, superfície corporal e integridade do parasita, analisadas pelo método de fluorescência. A intensidade de monogenéticos nas brânquias foi menor nos peixes anestesiados pelo método de imersão em comparação com o método de aspersão e o grupo controle. O método de anestesia por aspersão nas brânquias pode ser utilizado em estudos parasitológicos.

Fish sperm subpopulations: Changes after cryopreservation process and relationship with fertilization success in tambaqui (Colossoma macropomum).

Fish tambaqui (Colossoma macropomum) is the native Brazilian fish with the highest agricultural production under intensive aquaculture in South America. However, the decrease in the genetic variability in fish farms has become necessary the improvement of cryopreservation process through new statistical studies of spermatozoa (like subpopulation studies). The evaluation of the kinetic data obtained with a computer-assisted sperm analysis system, applying a two-step cluster analysis, yielded in tambaqui three different subpopulations in fresh sperm: SP1, considered as a slow nonlinear subpopulation; SP2, considered as a fast nonlinear subpopulation, and finally; SP3, considered as a fast linear subpopulation. For cryopreserved sperm, the cluster analysis yielded only two sperm subpopulations: SP1', considered as a slow nonlinear subpopulation and SP2', which seemed to be an intermediate subpopulation (showing medium motility and velocity values) merged from SP2 and SP3 obtained from fresh sperm. Coefficients of correlation (r) and determination (r2) between the sperm subpopulations from fresh sperm and the fertilization rates were calculated, and SP2 and SP3 (the fast-spermatozoa subpopulations) showed a high-positive correlation with the fertilization rates (r = 0.93 and 0.79, respectively). In addition, the positive significant correlations found in curvilinear velocity (r = 0.78), straight line velocity (r = 0.57), and average velocity (r = 0.75) indicate that sperm kinetic features seem to be a key factor in the fertilization process in tambaqui, as occur in other fish species.

Anesthesia by sprinkling method in the gills of tambaqui Colossoma macropomum does not influence intensity and morphology of monogeneans.

The present study evaluates the influence of anesthesia on the parasitic fauna of monogenea fish parasites, as its intensity and viability. Two experiments were conducted: Evaluation of an anesthetic method by sprinkling eugenol directly on gills and evaluation of monogenea motility and viability; Comparison of immersion and directly sprinkling on the gills with benzocaine and eugenol followed by evaluation on parasite intensity. The results suggest that the anesthetic sprinkling didn't interfere in the parasite motility, morphology and body surface integrity analyzed by fluorescence method. The monogenean intensity in the gills was lower in fish anesthetized by immersion method compared to the sprinkling method and the control group. This method of anesthesia can be used in parasitological studies.

Characterization of the acute inflammatory response in the hybrid tambacu (Piaractus mesopotamicus male x Colossoma macropomum female) (Osteichthyes).

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

Characterization of the acute inflammatory response in the hybrid tambacu (Piaractus mesopotamicus male × Colossoma macropomum female) (Osteichthyes) / Caracterização da resposta inflamatória aguda no híbrido tambacu (Piaractus mesopotamicus macho × Colossoma macropomum fêmea) (Osteichthyes)

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

Este estudo avaliou a resposta inflamatória aguda induzida por injeções de 0,5 mL de solução salina (controle), 500 µg de carragenina e 0,5 mL de tioglicolato a 3 por cento na bexiga natatória de juvenis do híbrido tambacu. Os peixes foram distribuídos em três tratamentos, três repetições e aclimatados durante 10 dias antes do ensaio. A caracterização das células do exsudato inflamatório foi feita após coloração com Giemsa e PAS. Peixes injetados com carragenina apresentaram maior número de células no exsudato inflamatório do que com salina e tioglicolato. A porcentagem de trombócitos no exsudato foi maior nos injetados com carragenina quando comparada com a dos injetados com tioglicolato. Por outro lado, o percentual de granulócitos foi maior em animais injetados com tioglicolato do que em animais injetados com carragenina. A carragenina provocou maior migração de macrófagos para o foco inflamatório. O método de PAS confirmou a presença de três tipos de granulócitos: célula granular eosinofílica (CGE) tipo 1 com as características da célula granulocítica especial encontrada no sangue, CGE tipo 2, menor do que esta última, e de neutrófilos. Este estudo contribui para o melhor entendimento da resposta inflamatória e dos processos infecciosos em peixes nativos.

Protozoan parasites of Xiphophorus spp. (Poeciliidae) and their relation with water characteristics / Parasitos protozoários de Xiphophorus sp. (Poeciliidae) e a relação deles com as características da água

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 percent and 22.5 percent for I. multifiliis, and 13 percent and 54.2 percent 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.

Investigou-se a relação entre as características da água e a infestação de protozoários parasitos, Icthyophthirius multifiliis e Trichodina sp., em peixe espada, Xiphophorus helleri e em plati, Xiphophorus maculatus, coletados em uma piscicultura de peixes ornamentais no Estado de São Paulo, Brasil. Os peixes foram coletados mensalmente, durante um ano, dos viveiros e das caixas de estocagem. A prevalência da infestação nos peixes das caixas e dos viveiros foram, respectivamente, 34,2 por cento e 22,5 por cento para I. multifiliis e 13 por cento e 54 por cento para Trichodina sp. A elevada condutividade elétrica e o pH da água reduziram a infestação por I. multifiliis. A baixa concentração de oxigênio resultou em aumento na infestação por Trichodina sp. O uso do sal, para aumentar a condutividade elétrica da água, consistiu em um método de controle de I. multifiliis. A redução do oxigênio dissolvido e a adição de fertilizante orgânico favoreceram a reprodução de Trichodina sp.

Experimental infection in Notodiaptomus sp. (Crustacea: Calanoida) with larvae of Camallanus sp. (Nematoda: Camallanidae)

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 28.1°C, 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 percent 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 percent) when compared to 105 copepods and 120 larvae (33.2 percent). 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.

A viabilidade da infecção experimental com larvas do nematóide Camallanus sp. em Notodiaptomus sp., crustáceo com potencial para hospedeiro intermediário foi avaliada. Fêmeas adultas do nematóide foram extraídas de Xiphophorus maculatus (Osteichthyes: Poeciliidae), provenientes de piscicultura de peixes ornamentais no estado de São Paulo. As fêmeas foram ligeiramente pressionadas para liberar as larvas, coletadas com pipeta Pasteur e separadas em placas de Petri contendo 9ml de água filtrada a 28,1°C do próprio cultivo de zooplâncton. Os tratamentos consistiram de placas contendo 60 e 105 copépodes onde se adicionou 120, 150 e 210 larvas de nematóides em quatro repetições. Nos tempos de 24 e 36h após a exposição às larvas, os copépodes foram fixados em álcool 70 por cento para quantificação de larvas. Após 24h de exposição, o grupo com 60 copépodes na presença de 120 larvas apresentou maior prevalência (46,5 por cento) do que 105 copépodes com 120 larvas (33,2 por cento). Sugere-se que 120 larvas foram suficientes para o sucesso da infecção. A infecção experimental mostrou-se viável, servindo de modelo para o estudo do ciclo de vida de camalanídeos e testes de susceptibilidade de hospedeiros.

Haematological alterations of Leporinus macrocephalus (Osteichtyes: Anostomidae) naturally infected by Goezia leporini (Nematoda: Anisakidae) in fish pond

Estudou-se efeito da infecção por Goezia leporini Martins & Yoshitoshi, 2003 (Nematoda: Anisakidae) sobre as características hematológicas de Leporinus macrocephalus (Osteichthyes:Anostomidae) cultivado. Palidez das brânquias, rins, fígado e coração, pontos negros nos rins e acúmulo de líquido na cavidade visceral, estômago e intestinos foram observados. O conteúdo da vesícula biliar tinha aparência pálida e translúcida. Observaram-se alta e moderada correlações positivas entre número de nematóides e peso do peixe estimadas dentro dos grupos de peixe de 0-100g e 100-200g, respectivamente. As extensões sangüíneas revelaram variações no tamanho (anisocitose) e forma (poiquilocitose) dos eritrócitos, bem como eritrócitos em divisão. Não houve alteração (P>0,05) na contagem total de eritrócitos, de leucócitos, na taxa de hemoglobina e nos percentuais de trombócitos e monócitos. A infecção provocou redução (P<0,05) no percentual de hematócrito, no volume corpuscular médio, na concentração de hemoglobina corpuscular média e no percentual de linfócitos, e aumento (P<0,05) no percentual de neutrófilos e eosinófilos no sangue circulante de peixes infectados. Este é o primeiro relato no Brasil que relaciona hematologia e infecção por nematóides em peixes cultivados.

Prevalence and histopathology of Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae) in Prochilodus lineatus Valenciennes, 1836 from Volta Grande Reservoir, MG, Brazil.

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

Prevalence and histopathology of Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae) in Prochilodus lineatus Valenciennes, 1836 from Volta Grande Reservoir, MG, Brazil

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

Recent Studies on Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae), in Prochilodus lineatus Valenciennes, 1836, from Volta Grande Reservoir, MG, Brazil

The present work described helminth parasites of curimbatá, Prochilodus lineatus Valenciennes, 1836 from Volta Grande Reservoir, MG, Brazil. Eighteen fishes with average 46.7 + or - 1.1 cm length and 1,674.8 + or - 75.6 g weight were collected. Of the analysed fishes, 15 were parasitized with acanthocephalans in the intestine, showing a prevalence of 83.3 percent. The helminth was identified as Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae). It differs from other species in dimension of characters and morphology. From the original description of N. curemai, it differs from the biggest dimension of testis, elongated cement gland, nucleated lemnisci, eggs size, larger proboscis hooks length in the middle and in the third circle in males and larger hooks in the anterior circle in females. A smaller percentage occupied by the reproductive system in female trunk was reported. The observation of paratypes of N. curemai of Noronha (1973) showed a great similarity with those of the present work. This fact complements the helminth description from elsewhere