Pesque-solte: pesca repetitiva, variáveis hematológicas e parasitismo no peixe híbrido tambacu

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.

Água levemente salinizada aumenta a eficiência da larvicultura de peixes neotropicais

The objective of this work was to evaluate the effect of slightly saline water in an intensive larviculture of tambaqui, matrinxã, apaiari, and piau, during the initial days of active feeding. Larvae were reared in artificial saline water, at concentrations from 0 (freshwater) to 14 g L-1 NaCl (at a 2.0 g L-1), and fed with two portions of Artemia nauplii, following a specific protocol for each species, in a completely randomized design, with 3 replicates. Tambaqui, matrinxã and apaiari larvae can be reared at saline concentrations till 2 g L-1 without impairing growth and survival. Piau larvae were more tolerant and endured saline water until 4 g L-1. At saline concentrations above that, fish mortality increased and reached 100% at 6 g L-1, for matrinxã and apaiari, and at 10 g L-1, for tambaqui. Saline water at 2 g L-1 provided a higher survival for matrinxã, and higher growth for tambaqui, apaiari and piau. These last two species showed a better growth performance with the highest quantity of nauplii. Slightly saline water at 2 g L-1 is beneficial to these studied species, as it optimizes larval growth potential and the use of Artemia nauplii as live food.

Desempenho produtivo e respostas fisiopatológicas de tambaquis alimentados com ração suplementada com β-glucano

O objetivo deste trabalho foi avaliar o efeito do imunoestimulante β-glucano na dieta do tambaqui (Colossoma macropomum) sobre o desempenho produtivo, as respostas fisiológicas e imunológicas, e a resistência ao desafio com Aeromonas hydrophila. O experimento foi conduzido em delineamento inteiramente casualizado, em arranjo fatorial 5x2, com cinco níveis de β-glucano na dieta (0, 0,1, 0,2, 0,4 e 0,8%) e dois tempos de amostragem (antes e após o desafio com A. hydrophila), com três repetições. Os peixes (28,65±0,49 g; 12,14±0,07 cm) foram alimentados, por 60 dias, com dieta (28% de proteína bruta) suplementada com preparação comercial de β-glucano. Após o período de alimentação, avaliou-se o desempenho produtivo, e os peixes foram desafiados com A. hydrophila. Os parâmetros hematológicos e imunológicos (concentração e atividade de lisozima) foram avaliados antes e após o desafio bacteriano. Após o desafio bacteriano, observouse a ocorrência de anemia normocítica-normocrômica. A suplementação com β-glucano não alterou a concentração nem a atividade da lisozima; porém, a menor concentração de β-glucano (0,1%) favoreceu maior sobrevivência para a espécie quando desafiada com Aeromonas hydrophila. A suplementação de β-glucano não exerce influência sobre o desempenho produtivo e nem sobre os parâmetros hematológicos do tambaqui.

Variáveis hematológicas em tambaquis anestesiados com óleo de cravo e benzocaína

The objective of this work was to evaluate the anesthetic effect of clove oil and benzocaine on the hematology and osmotic fragility of erythrocytes in tambaqui (Colossoma macropomum). Thirty adult fish were evaluated in three treatments: a control, without anesthetic; anesthesia with clove oil at 50 mg L-1; and anesthesia with benzocaine at 100 mg L-1. Blood was collected for hemogram determination, and a test for the erithrocyte osmotic-fragility was applied. The utilized doses of clove oil and benzocaine are not appropriate for hematologic studies to establish reference values for tambaqui because they cause significant changes of the hematologic parameters, such as leukocytosis and iatrogenic hemolysis.

Análise econômica da criação de tambaqui em tanques-rede: estudo de caso em assentamento da reforma agrária

Aquaculture is a crucial source of income and livelihood for millions of people around the world. Most fish farms require technical knowledge expertise and qualified staff. This research was developed in Santa Felicidade Settlement Project Cocalzinho de Goias city - GO, where a substantial part of the settlers by INCRA are exploring subsistence farming activities. After meeting open to the 76 settler's families, those who joined the project received courses on intensive farming of tambaqui (Colossoma macropomum) in net cages. The production was an innovative technique, fully realized with the participatory labor of family members, without prejudice of the main activities. The economic analysis showed the return on invested capital in 7.5 years within the financial activity with 7.1% Internal Return Rate higher than the average interest rate market. The Net Cash Flow showed ability to fulfill financial obligations from the second year. The implementation of more productive cycles optimizes the workforce with increased operational efficiency. Diet alternatively produced with local ingredients can minimize the effects of critical variables of the project, since it does not affect productivity.

Genetic Identification of F1 and Post-F1 Serrasalmid Juvenile Hybrids in Brazilian Aquaculture

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exigência de proteína digestível em dietas para juvenis de tambaqui e a dinâmica do crescimento muscular por aspectos morofológicos e turnover isotópico do carbono-13 e do nitrogênio-15

Pós-graduação em Zootecnia - FCAV

Characterization of the commercial fish production landed at Manaus, Amazonas State, Brazil

The present work aims to update a series of information about the regional fishing production, by presenting and characterizing the contribution of the different sub-systems of the Amazon basin to the catch landed at the main fishing market of Manaus, Brazil, from 1994 to 1996. Collectors specifically hired for this function registered key information on the fisheries. Thirty nine types or groups of fish were found in the fishing production landed. Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã (Brycon cephalus), sardine (Triportheus spp.), aracu (Anostomidae) and tambaqui (Colossoma macropomum) were the most important items during three consecutive years. In 1994 these items summed up 91.6% of the total production; in 1995 and 1996 these values were, respectively, 85.3% and 86.4% of the total production. Tambaqui landed decreased remarkably during the period 1976-1996. There was a strong seasonal component in the production of the main species; jaraqui and matrinchã were mostly landed between April and June, while curimatã, pacu, and sardine were mostly landed during the dry season. Other important items showed a strong inter-annual variation in their production. The fishing production landed came mostly from the sub-system of the Purus River (around 30% of the total production). The subsystem of the Medium-Solimões contributed with an average of 15% and the sub-systems of the Madeira, Lower-Solimões, Upper-Amazon and Juruá, together contributed with 11.5% of the total production landed. Finally, the remaining sub-systems contributed with only 7.6% of the production.

Influência da temperatura e da concentração do cloreto de sódio (NaCl) nas isotermas de sorção da carne de tambaqui (Colossoma macroparum)

As isotermas de sorção da carne de tambaqui desidratada osmoticamente foram determinadas a três temperaturas (5, 17 e 29ºC) e com duas concentrações de solução osmótica (10 e 30% de NaCl), pelo método gravimétrico. Quatro modelos de sorção foram testados para verificar o melhor ajuste; GAB, Oswin, BET e PELEG. Os dados experimentais se ajustaram satisfatoriamente aos modelos. O modelo escolhido para este trabalho foi o de PELEG. Para o ajuste nas curvas de sorção, foi feita a análise de regressão não-linear, usada o programa estatístico ORIGIN 4.0 para estimar as constantes dos modelos. A avaliação do melhor ajuste foi feita pela análise do coeficiente de determinação do ajuste (r²) e teste de Qui-quadrado (x²). Foram analisadas as influências da variação da temperatura e concentração de NaCl na atividade de água da carne do tambaqui. À medida que decresce a temperatura há um decréscimo na atividade de água. Um aumento na concentração do NaCl diminui a atividade de água. A propriedade termodinâmica estudada foi o calor isostérico de sorção. A medida que aumenta a concentração da solução osmótica aumenta o valor do calor isostérico de sorção.

Características morfológicas do miocárdio ventricular de Tambaqui (Colossoma macropomun; Characidae, Cuvier, 1818)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Induced ovulation and rearing of the pacu (Colossoma mitrei)

A method is described for spawning the economically important Brazilian characin species Colossoma mitrei. Ovulation was induced using a priming injection of 0.2 mg/kg partially purified gonadotropin SG-G100 followed at 8 h by injecting an extract of 20 mg/kg acetone-dried chum salmon pituitary powder. Spermiation was induced in the male using a similar primer followed by 14 mg/kg acetone-dried chum salmon pituitary powder. Eggs were successfully fertilized and incubated at 25-26°C. Hatching occurred at 20.5 h and a survival of 10% to fingerling size was achieved. © 1981.

Valores de DL50 em peixes e no rato tratados com pó de raízes de Derris spp e suas implicações ecotoxicológicas

Os timbós verdadeiros (plantas do gênero Derris), originários da Amazônia Brasileira, tem demonstrado importância crescente por produzirem uma classe de compostos flavonoídicos relacionados à rotenona, que possuem atividade tóxica para peixes e mamíferos. Neste estudo foi determinado a dose letal 50% (DL50) do extrato alcoólico do pó de Derris spp para três espécies de peixes filogeneticamente diferentes e um mamífero roedor (rato). As DL50 de 2,6 microgramas/ml para Collosoma macropomum (tambaqui), 4,8 microgramas/ml para Oreochromis niloticus (tilápia), 14,2 microgramas/ml para Plecostomus sp (cascudo) e DL50 de 100,0 mg/kg para Rattus norvegicus (rato) denotam acentuadas diferenças entre os valores de DL50, principalmente entre os peixes e o rato. Isto possivelmente é devido a fatores farmaco-cinéticos que se relacionam com as diferentes barreiras teciduais encontradas pelos rotenóides quando administrados pela via oral em mamíferos.

The effect of ions and adenosine nucleotides on the activity of lactate dehydrogenase from the epaxial muscle of fish

Lactate dehydrogenase was partially purified from the epaxial muscle of Piaractus mesopotamicus (pacu) and its hybrid Piaractus mesopotamicus x Colossoma macropomus (tambacu). This preparation was used for kinetic studies carried out at pH 6.0 and 7.5. It was also used for the study of the inhibition properties of adenosine nucleotides = ATP, ADP, AMP =, divalent ions Ni2+, Cu2+, Co2+ and the anions oxamate and oxalate.