Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L^-1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure.

Differential Expression of Myogenic Regulatory Factor Genes in the Skeletal Muscles of Tambaqui Colossoma macropomum (Cuvier 1818) from Amazonian Black and Clear Water

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

Níveis de aminoácidos digestíveis para juvenis de tambaqui, Colossoma macropomum e turnover isotópico do carbono - 13 e do nitrogênio - 15 no tecido muscular

Pós-graduação em Zootecnia - FCAV

Differential expression of a retrotransposable element, Rex6, in Colossoma macropomum fish from different Amazonian environments

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

Indução à triploidia no tambaqui Colossoma macropomum, pacu Piaractus mesopotamicus e o respectivo híbrido tambacu

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Níveis de carboidratos e lipídios em dietas para juvenis de tambaqui (Colossoma macropomum): variáveis produtivas, fisiológicas e turnover isotópico

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

Innovative molecular approach to the identification of Colossoma macropomum and its hybrids

Tambaqui (Colossoma macropomum) is the fish species most commonly raised in the Brazilian fish farms. The species is highly adaptable to captive conditions, and is both fast-growing and relatively fecund. In recent years, artificial breeding has produced hybrids with Characiform species, known as “Tambacu” and “Tambatinga”. Identifying hybrids is a difficult process, given their morphological similarities with the parent species. This study presents an innovative molecular approach to the identification of hybrids based primarily on Multiplex PCR of a nuclear gene (a-Tropomyosin), which was tested on 93 specimens obtained from fish farms in northern Brazil. The sequencing of a 505-bp fragment of the Control Region (CR) permitted the identification of the maternal lineage of the specimen, all of which corresponded to C. macropomum. Unexpectedly, only two CR haplotype were found in 93 samples, a very low genetic diversity for the pisciculture of Tambaqui. Multiplex PCR identified 42 hybrids, in contrast with 23 identified by the supplier on the basis of external morphology. This innovative tool has considerable potential for the development of the Brazilian aquaculture, given the possibility of the systematic identification of the genetic traits of both fry-producing stocks, and the fry and juveniles raised in farms.

Mudanças climáticas previstas para o final do século afetam o desempenho e o desenvolvimento esquelético de larvas de tambaqui (Colossoma macropomum)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphological structure of the liver in tambaqui, Colossoma macropomum (Cuvier, 1818)

This research aimed to describe the macroscopic and microscopic liver of tambaqui, Colossoma macropomum, Teleost freshwater Family Characidae, of great economic interest for the Amazon basin. We used six juveniles aged between six month and one year, from the small holding Esteio, Alta Floresta/MT, that develops mainly fish farming. The body was photographed in situ, described macroscopically, and fragments were removed and processed by routine histological techniques through paraffin embedding and HE staining. The liver, located ventrally to the swim bladder and craniodorsally to the stomach, is brownish red and consisted of three lobes, the right lateral, the left lateral and the ventral lobe. Microscopically, the parenchyma consists of hepatocytes varying from irregular rounded hexagonal to round forms with a large and central nucleus, and arranged in linear strings limited by sinusoids and radiating to central veins, but with absence of liver lobules. The central veins are distributed throughout the parenchyma, while the portal space consists in most cases only of a hepatic vein and bile duct; elsewhere exist artery and duct. Formation of portal triads was not founde. Melano macrophages were frequently seen dispersed throughout the central parenchyma. The morphofunctional study of the digestive system of fishes of the Amazon basin is important to obtain knowledge about their weight gain, large scale production for human consumption and preservation of the species, and has also its importance for being used as bioindicators today.

Análise de genes responsáveis pela formação gonadal do tambaqui (Colossoma macropomum).

O presente trabalho buscou identificar o comprimento do peixe em que genes indutores da formação de ovários e testículos iniciam sua expressão no tambaqui.

Atividade antibacteriana do óleo essencial de espécies de Lippia no controle de Aeromonas hydrophila isolados de tambaqui (Colossoma macropomum).

Este presente trabalho teve como objetivo avaliar a atividade antibacteriana do OE de Lippia alba, Lippia origanoides e Lippia sidoides cultivadas nas condições de Manaus, AM, frente a isolados da bactéria A. hydrophila, avaliando também a suscetibilidade do isolado frente ao mesmo OE.

Clonagem e análise de expressão de candidatos a genes de referência em tambaqui (Colossoma macropomum).

Neste trabalho, os genes 18S, beta-actina, gapdh e ef1alfa do tambaqui foram clonados e sequenciados, visando à obtenção e validação de genes de referência, candidatos aos estudos genômicos e de fisiologia na espécie.

Eficácia da folha da bananeira (Musa sp.) no controle de Monogenea, parasita de tambaqui (Colossoma macropomum).

O objetivo deste trabalho foi avaliar a eficácia da folha da bananeira (Musa sp.) no controle de monogeneas, parasitas de tambaqui (Colossoma macropomum).

Indução anestésica com óleo essencial de Lippia alba e respostas fisiológicas ao estresse de manuseio em tambaqui (Colossoma macropomum).

O presente estudo avaliou a atividade anestésica do óleo essencial de Lippia alba em tambaqui (Colossoma macropomum) e as respostas fisiológicas de estresse decorrentes da anestesia e do manuseio para biometria.

Respostas fisiológicas do tambaqui (Colossoma macropomum) alimentado com rações contendo farinha de folha de bananeira (Musa sp.).

O objetivo deste trabalho foi avaliar a eficácia da farinha de folha de bananeira (Musa sp.) na alimentação de tambaqui sobre os parâmetros hematológicos, as respostas metabólicas e o desempenho zootécnico.