Rodrigo Yudi Fujimoto

Morphological and hematological studies of Trypanosoma spp. infecting ornamental armored catfish from Guamá River-PA, Brazil

A total of 281 specimens of freshwater armored ornamental fish species (Leporacanthicus galaxias,Lasiancistrus saetiger, Cochliodon sp., Hypostomus sp., Pseudacanthicus spinosus, Ancistrus sp. and Rineloricaria cf. lanceolata) were captured at the hydrological basin of Guamá River, Pará, Brazil. The infection by Trypanosoma spp. was inspected. The morphological and morphometric characterization of the parasites and the hematological parameters were determined. Leporacanthicus galaxias and Pseudacanthicus spinosus presented 100% infection prevalence, and the other species showed a variable prevalence of infection. The parasites showed clearly different morphotypes and dimensions, and probably belong to different species. The hematological response to the infection varied with the host. Cochliodon sp. showed no differences between infected and not infected fish. In other species several modifications on some hematological parameters were found, but apparently without causing disease. It is emphasized the possibility of introduction of the parasites in new environments due to the artificial movements of these ornamental fish.

Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius) exposed to formalin

The objective of this work was to evaluate the acute toxicity of formalin and histopathological effects on the Amazon ornamental fish, bluespotted coridora (Corydoras melanistius). A randomized design was used, with ten concentrations of formalin (40%) (0, 3, 6, 12, 25, 50, 100, 150, 200 and 250 mg.L(-1)) with four replicates and five fish per container (3L) in static system for 96 hours. The moribund fish were killed and fixed in 10% formalin to proceed the histopathological analysis of gill, liver and kidney. At the end of this experiment the following mortality rates (%) were obtained in increasing order of exposure: 0, 0, 0, 0, 0, 65, 85, 100, 100 and 100%. The lethal concentration 50% (LC(50-96h (I))) estimated was 50.76 mg.L(-1) with regression of y = 0.51x, and r(2) = 0.80. Further, in higher concentrations morphological changes as gill hyperplasia, with filling of interlamellar spaces, disorganization of liver arrangement, and necrosis in kidney were observed. In this study, the formalin can be considered slightly toxic to bluespotted corydora, and cause morphological changes when exposed to high concentrations. The use of formalin to treat of ornamental fish in the inner river of capture with wrong concentration can provoke negative environmental and biological effects.

Trichodinidae in commercial fish in South America.

Ciliates of the family Trichodinidae are protozoan parasites of importance for fish farming in South America, given that at high infestation levels, they cause significant mortality among farmed fish. Although data on economic losses due to parasitosis are not available for South America, mortality outbreaks correlated to trichodinids are very common in the tilapia production chain, especially in Brazil, the largest aquaculture chain in the country. In Brazil in the past, trichodinids were considered only as Trichodina sp. Today, they have been better studied and identified taxonomically in wild and farmed fish. However, in other countries in South America, trichodinids continue to be described only as Trichodina sp. This review presents the history of occurrences of trichodinids in fish of interest in South America, highlighting 15 new species that have been described in three genera in Brazil, along with information on parasite-host-environment relationships, diagnostic methods and treatments. The occurrence of parasitic ciliates must be correlated with farming conditions such as stress factors, water quality, seasonality, age and host immunity to elucidate the critical points of each production system. Furthermore, for tropical fish, studies on treatment against trichodinid species are needed to provide support for approval of antiparasitic medications for use in fish farming. However, it is recommended that the production sector use intensive production systems that are more sustainable, with biosafety protocols, to increase production and productivity.

Morphological deformities in the osseous structure in spotted sorubim Pseudoplatystoma coruscans (agassiz & spix, 1829) with vitamin c deficiency

Vitamin C is essential for fish diets because many species cannot syntethize it. This vitamin is needed for bone and cartilage formation. Moreover, it acts as antioxidant and improve the immunological system. The present work investigated the effects of vitamin C diet supplementation to spotted sorubim (Pseudoplatystoma coruscans) fingerlings by frequency of bone and cartilage deformation. Ascorbyl poliphosphate (AP) was used as source of vitamin C in the diets for spotted sorubim fingerlings during three months. Six diets were formulated: one diet control (0 mg/kg of vitamin C) and 500, 1,000, 1,500, 2,000 and 2,500 mg AP/kg diets. Fishes fed without vitamin C supplementation presented bone deformation in head and jaws, and fin fragilities. Thus, 500 mg AP/kg diet was enough to prevent deformation and the lack of vitamin C supplementation worsening the development of fingerlings.

Crescimento de tambaqui em resposta a densidade de estocagem em tanques-rede

The tambaqui Colossoma macropomum is rearing on different systems and environments and has shown good production in cages. The aim of this study was to evaluate the growth of tambaqui at different stocking densities in a lake supplied by rainwater and its effects on environmental quality. The experiment was conducted in consecutive phases: nursery at densities of 50, 100, 200 and 300 fingerlings m-3 and growth at densities of 20, 40 and 60 juveniles m-3. Water temperature, dissolved oxygen, pH and conductivity were monitored daily. Sediment and water samples were collected for analyses of nitrogen and phosphorus monthly. In the nursery, yield of 14,03 kg m-3 was significantly higher for fish at 300 fingerlings m-3. The highest weight gain was obtained at 50 fingerlings m-3. Survival over 97% was observed in the nursery. In the growth phase, weight gain and specific growth were inversely proportional to densities. Feed conversion and condition factor were not influenced by the evaluated densities. The density of 20 juveniles m-3 is more adequate to grow tambaqui in cages. Tambaqui cage culture did not alter the levels of nitrogen and phosphorus nutrients of lake water. Increased levels of organic matter, nitrogen and phosphorus in the sediment below the cages were verified without creating events of eutrophication. The results show that the tambaqui cage culture is viable in lakes provided with rainwater and can be integrated with multiple-use water services.

Seasonality of nematode larvae in Iguanodectes spilurus (Characidae) an ornamental fish from northeastern Para, Brazil

The current study presents a parasitological survey of larval nematodes from freshwater ornamental fish Iguanodectes spilurus caught in the watercourse of the Caete River, in the northeast region of the State of Para, Brazil. A total of 176 specimens, 1.36±0.75 g weight and 5.53±0.98 cm total length, were analyzed. Nematode larvae were identified as Capillaria sp., Procamallanus sp. and Anisakidae, with prevalence of 70.45% and infection intensity ranging from 1.81 to 4.70 larvae. The highest prevalence 57.38% occurred in the liver, but no seasonality was observed, indicating high infection throughout the year. Seasonality was observed in fish parasitized in the stomach, intestine and caecum, with prevalence and mean intensity of 17.61% and 2.32 parasites, 12.5% and 1.81 parasites, 10.79% and 2.21 parasites, respectively. The highest degree of infection was observed in the rainy season, probably due to increased availability of intermediate hosts or food.

Parasites of four ornamental fish from the Chumucuí River (Bragança, Pará, Brazil)

The objective of the present study was to evaluate the parasite fauna of four species of ornamental fish collected in the Chumucuí River, municipality of Bragança, Pará, Brazil. From June 2006 to December 2007. Fishes (n=307) belonging to four species were collected, including 23 specimens of Moenkhausia sanctaefilomenae (redeye tetra), 37 Carnegiella strigata (marbled hatchetfish), 7 Chilodus punctatus (spotted headstander), and 240 Astyanax bimaculatus (twospot astyanax). The parasites found belonged to three taxa: monogeneans in the gills, nematodes (larvae of Capillaria sp. and Contracaecum sp.) in the digestive tract and liver and acanthocephalans (Quadrigyrus torquatus, Q. brasiliensis and Q. nickoli) in the stomach and intestine. Astyanax bimaculatus presented higher prevalence of acanthocephalans in the wet season, and lower prevalence of nematodes in the dry season. The possible importance of these parasites in the exportation of ornamental fish is discussed.

Efeitos do tratamento com formalina e sulfato de cobre sobre os parâmetros hematológicos e parasitos monogenéticos em juvenis de Hemigrammus sp. (Osteichthyes: Characidae)

O objetivo deste trabalho foi avaliar a eficacia da formalina e sulfato de cobre no controle de monogeneticos em juvenis de Hemigrammus sp e seu efeito na contagem diferencial de leucocitos. Utilizou-se um delineamento inteiramente casualizado com 5 tratamentos e 3 repeticoes. Todos os tratamentos tiveram duracao de tres dias e corresponderam a: T1, controle; T2 e T3 banho por imersao de uma hora em formalina, em duas concentracoes uma de 0,25 ml e outra 0,1 ml formalina L-1; o T4, banho de 24 horas com 0,025 ml de formalina L-1; e o T5, banho de 24 horas com sulfato de cobre (0,3 mg L-1). Apos o periodo experimental observou-se que em T2 ocorreu 100% de mortalidade. O T3 e T5 proporcionaram eficacia de 100%, porem os peixes apresentaram intoxicacao e mortalidades de 66 e 80%, respectivamente. T4 apresentou eficacia de 77,7% e diminuicao dos indices parasitologicos: numero total de parasitos de 11,3± 9, intensidade media de infeccao de 3,2± 2 e prevalencia de 47,1%. Quanto aos leucocitos observou-se que no T3, T4 e T5 ocorreram diferencas na proporcao de linfocitos, monocitos e neutrofilos em relacao ao controle. O CuSO4 e a formalina reduzem a carga parasitaria, mas apresentaram-se toxicos nas maiores concentracoes.

Dermocystidium sp. infection in farmed hybrid fish Colossoma macropomum × Piaractus brachypomus in Brazil

European Regional Development Fund (ERDF) through the COMPETE – Operational Competitiveness Programme; FCT – Foundation for Science and Technology; National Council for Scientific and Technological Development (CNPq), Grant/Award Number: 305195/2016-6, 305869/2014-0; CAPES/ EMBRAPA / Participation of J.C. Eiras was partially supported by the European Regional Development Fund (ERDF) through the COMPETE – Operational Competitiveness Programme, and national funds through FCT – Foundation for Science and Technology, under the project “Pest-C/MAR/LA0015/2011. The authors thank National Council for Scientific and Technological Development (CNPq) for financial support to R. Y. Fujimoto (305195/2016-6), M.L. Martins (305869/2014-0) and CAPES/EMBRAPA (15/2014) for PhD scholarship to N.C. Sousa.

Resposta hematológica do cascudo ornamental amazônico Peckoltia oligospila ao estresse de transporte.

O objetivo deste trabalho foi avaliar as respostas hematologicas do acari-bola Peckoltia oligospila submetido ao estresse de transporte. Variacoes nos parâmetros de sangue foram analisadas as zero, seis, 24, 48, 72 e 96 horas apos 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 apos transporte) foi o mais critico, com valores elevados de glicemia, eritrocitos e eritroblastos. Respostas secundarias tardias foram observadas para a proteina plasmatica total, o volume corpuscular medio (VCM) e a hemoglobina corpuscular media (HCM) em seis horas apos o transporte dos peixes, retornando aos valores basais apos esse periodo. O numero de leucocitos nao sofreu alteracoes apos o transporte. O estresse de transporte nao comprometeu a fisiologia de P. oligospila, o que indica que esse peixe e resistente ao estresse se comparado com outras especies. Porem, recomenda-se que nao se realize qualquer outro procedimento estressante durante pelo menos 24 horas da recuperacao dos peixes apos transporte, para garantir a saude e a sobrevivencia dos animais transportados.