ABSTRACT The tissue response of the fish Gambusia punctata (Poey, 1854) grown under natural conditions under chronic heavy metal exposure is reported. Adult individuals of both sexes were captured 10 km downstream of a former open-pit mining area in Santiago de Cuba, Cuba. Branchial deformities with moderate extension were identified in 80% of the investigated individuals. Likewise, 100% presented numerous ferric iron deposits inside the enterocytes.

RESUMEN Se notifica la respuesta tisular del pez Gambusia punctata (Poey, 1854) crecido en condiciones naturales bajo la exposición crónica de metales pesados. Se capturaron individuos adultos de ambos sexos, a 10 km aguas debajo de una antigua zona minera a cielo abierto en Santiago de Cuba, Cuba. Se identificaron deformaciones branquiales con una extensión moderada en el 80% de los individuos investigados. Asimismo, el 100% presentó numerosos depósitos de hierro férrico en el interior de los enterocitos.

ABSTRACT Biofloc technology (BFT) has several advantages, such as low water supply requirements and apparent feed conversion ratio (FCR), and high densities. However, there is no information on adequate densities and their effect on the large-scale production of different species. In this study, we determined the effects of the stocking density of monosex red tilapia reared using BFT on the growth performance, water quality parameters, and chemical characteristics of fish on a large scale and under culture conditions in eastern Colombia. In total, six circular tanks (diameter: 14 m, height: 1 m, and capacity: 153 m³) were used in this investigation. Two stocking densities were considered: treatment 1 (T30: 30 fish/m³) and treatment 2 (T40: 40 fish/m³), in triplicate. The water quality parameters of the two treatment densities were within the normal ranges for the species, but dissolved oxygen decreased throughout the production process. The T30 and T40 treatments did not result in significant differences in growth performance. At the end of the trial, the FCRs were 1.6 and 1.7 from T30 and T40, respectively. Fishes raised at a lower density had a similar weight gain; however, their final biomass was not significantly different. BFT did not affect the nutritional characteristics of fish; the percentage of protein (%) in tilapia was 17.81% ±1% and 16.72% ±1% in the T30 and T40 groups, respectively. None of the fish were infected by Salmonella spp. or Vibrio cholerae.

RESUMO Tecnologia de bioflocos (BFT) tem vantagens em termos de redução do fornecimento de água, redução da taxa aparente de conversão alimenta FCR e aumento das densidades. Entretanto, não há informações sobre densidade adequadas e seu impacto na produção em largas escala das diferentes espécies. Este estudo teve como objetivo determinar os efeitos da densidade de povoamento da tilápia vermelha masculinizada no BFT sobre desempenho produtivo, parâmetros de qualidade da água e características químicas dos peixes em larga escala e sob condições de cultivo no leste da Colômbia. Foram usados seis tanques circulares de 14 m de diâmetro, com capacidade de 153-m3, as densidades estudadas foram tratamento 1 (T30-30 peixes/m³) e tratamento 2 (T40-40 peixes/m³), em triplicado. Os parâmetros de qualidade da água das duas densidades estavam dentro das faixas normais para a espécie, mas o oxigênio dissolvido tendia a diminuir durante todo o processo de produção. As densidades de estocagem de T30 e T40, respectivamente, não resultaram em diferenças significativas no desempenho de crescimento. No final da experiência, FCR eram 1,6 e 1,7 de T30 e T40, respectivamente. Os peixes produzidos com menor densidade tiveram um ganho de peso semelhante; entretanto, a biomassa final não apresentou diferenças significativas. O BFT não afetou as características nutricionais, a porcentagem (%) de proteína foi 17.81 ±1 e 16.72 ±1 para T30 e T40, respetivamente. Não há presença de bactérias Salmonella spp. e Vibrio cholerae na carne de tilápia.

Abstract Feeding accounts for 50%-60% of production costs in fish farming, and alternative raw materials are used to lower production costs. These raw materials can alter nutritional values and sensory aspects of the final product. The present study describes the results for the proximal composition, sensory, and microbiological analyses of red tilapia (Oreochromis sp.) fed with a biofloc meal (fish sediment residue). The results showed that the red tilapia biofloc meal contained protein levels over 30%, with 3% nitrogen and 6% calcium. Fish fed biofloc meal showed productive performances within the ranges established for the species. Sensory analysis revealed that the cooked product’s appearance was very characteristic, presenting a slight metallic flavor and moderate juiciness. The bromatological composition analysis indicated that each 100g of tilapia contained 16 g of protein. Finally, the microbiological study guarantees compliance with the local tandards and confirms that the product does not contain significant levels of microorganisms that could cause foodborne diseases when consumed by humans. In conclusion, the use of biofloc meal at a small red tilapia farm proved to be a sustainable alternative for feeding Oreochromis sp.

Two cases of canines infected with Hepatozoon canis are described in the city of Cúcuta, Colombia. The first patient of 18 months of age came to consultation with vomiting, anorexia, and progressive weight loss. In the second case, it was intended to perform preventive ovariohysterectomy, but the patient presented anemia in the pre-surgical clinical tests. For both cases, the diagnosis was by blood smear, observed at 100X. For the second case the diagnose was confirmed by PCR. The treatment established was symptomatic, using drugs such as oxytetracycline and doxycycline. This is the first report of hepatozoonosis in the city of Cúcuta.

Se describen dos casos de caninos infectados con Hepatozoon canis en la ciudad de Cúcuta, Colombia. La primera paciente de 18 meses de edad llegó a consulta con vómitos, anorexia y pérdida progresiva de peso. En el segundo caso se pretendía realizar ovariohisterectomía preventiva, pero en los exámenes clínicos prequirúrgicos presentó anemia. Para los dos casos, el diagnóstico fue mediante extendido sanguíneo, observado a 100X. Para el segundo caso, el diagnóstico se confirmó con la prueba de PCR. El tratamiento instaurado fue sintomático, usando fármacos como oxitetraciclina y doxiciclina. Este es el primer reporte de hepatozoonosis en la ciudad de Cúcuta.