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1.
Braz. j. biol ; 76(4): 1021-1028, Oct.-Dec. 2016. tab, graf
Artículo en Inglés | LILACS | ID: biblio-828095

RESUMEN

Abstract The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent.


Resumo A descarga de fósforo e nitrogênio via efluente do sistema intensivo de truticultura foi quantificada através da utilização de indicadores ambientais. As cargas de nutrientes, o balanço de massa, a quantidade estimada de nutrientes na ração e a quantidade de nutrientes convertidos em biomassa de peixes foram calculados com base nas concentrações de fósforo (P) e nitrogênio (N) na ração e na água. Da ração oferecida, 24,75 kg estavam disponíveis como P e 99,00 kg como N, destes, 9,32 kg de P (38%) e 29,12 kg de N (25%) foram convertidos em biomassa de peixe e 15,43 kg P (62%) e 69,88 kg N (75%) foram exportados via efluente. As cargas e o balanço de massa mostram a descarga excessiva de nutrientes via efluente, corroborado pela taxa de conversão alimentar (2,12:1), devido à baixa eficiência na utilização da ração, portanto, propõe-se a utilização deste parâmetro zootécnico como indicador ambiental. Além disso, as práticas de manejo alimentar não são adequadas, destacando a baixa frequência de alimentação durante o dia, quantidade excessiva e baixa qualidade da alimentação ofertada. Esses resultados demonstram a necessidade de manejo alimentar adequado e de monitoramento do efluente.


Asunto(s)
Animales , Fósforo/análisis , Oncorhynchus mykiss/crecimiento & desarrollo , Explotaciones Pesqueras , Agua Dulce/química , Alimentación Animal/análisis , Nitrógeno/análisis , Contaminantes Químicos del Agua/análisis , Brasil , Biomasa
2.
Braz J Biol ; 76(4): 1021-1028, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27224731

RESUMEN

The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent.


Asunto(s)
Alimentación Animal/análisis , Explotaciones Pesqueras , Agua Dulce/química , Nitrógeno/análisis , Oncorhynchus mykiss/crecimiento & desarrollo , Fósforo/análisis , Animales , Biomasa , Brasil , Contaminantes Químicos del Agua/análisis
3.
J Comp Pathol ; 150(2-3): 258-65, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24016778

RESUMEN

In mammalian species, profibrogenic cells are activated to become myofibroblasts in response to liver damage. Few studies have examined hepatic myofibroblasts and their role in liver damage in teleosts. The aim of the present study was to investigate the involvement of myofibroblast-like cells in rainbow trout (Oncorhynchus mykiss) with hepatic damage induced by aflatoxin B1 (AFB1). Histopathological and immunohistochemical analyses characterized alterations in the liver stroma during the carcinogenic process. Anti-human α-smooth muscle actin (SMA) and anti-human desmin primary antibodies were used in immunohistochemistry. Only the anti-SMA reagent labelled cells in trout liver. In the livers of control fish, only smooth muscle in blood vessels and around bile ducts was labelled. In the livers from AFB1-treated fish, SMA-positive cells were present in the stroma surrounding neoplastic lesions and in areas of desmoplastic reaction. These observations indicate that in teleosts, as in mammals, the myofibroblast-like cell is involved in fibrosis associated with liver injury. Chronic liver injury induced in trout by aflatoxin may provide a useful model system for study of the evolution of such mechanisms.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hígado/patología , Miofibroblastos/patología , Aflatoxina B1 , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Inmunohistoquímica , Hígado/metabolismo , Miofibroblastos/metabolismo , Oncorhynchus mykiss
4.
Braz J Biol ; 67(2): 355-61, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17876448

RESUMEN

Growth is one of the most important aspects in the genetic improvement of cultured fish species. Consequently, genetic parameters related to this feature and their response to selection have been the focus of most research in this area. Such research indicates that, in general, there is enough additive genetic variance related to growth, justifying the use of selection. Based on the usefulness of cytogenetic and molecular markers in the fish culture, the aim of the present work was to analyze the possible relationships among cytogenetic characteristics, specifically the NOR phenotypes, and the increase in length and weight in specimens of the rainbow trout (Oncorhynchus mykiss), resultant from directed mating between homozygous females and heterozygous males according to their NOR phenotypic patterns. The equations of the relationship between length and weight of the analyzed specimens followed the model Wt = a Lt(b), showing b values higher than 3, determinant of a positive allometric growth. The results showed that the different NOR phenotypes were not related with the growth values for length and weight in any statistical test.


Asunto(s)
Acuicultura , Región Organizadora del Nucléolo/genética , Oncorhynchus mykiss/genética , Fenotipo , Selección Genética , Aumento de Peso/genética , Animales , Análisis Citogenético , Femenino , Heterocigoto , Homocigoto , Masculino , Modelos Genéticos , Oncorhynchus mykiss/crecimiento & desarrollo
5.
Braz. j. biol ; 67(2): 355-361, May 2007. ilus, graf, tab
Artículo en Inglés | LILACS | ID: lil-460010

RESUMEN

Growth is one of the most important aspects in the genetic improvement of cultured fish species. Consequently, genetic parameters related to this feature and their response to selection have been the focus of most research in this area. Such research indicates that, in general, there is enough additive genetic variance related to growth, justifying the use of selection. Based on the usefulness of cytogenetic and molecular markers in the fish culture, the aim of the present work was to analyze the possible relationships among cytogenetic characteristics, specifically the NOR phenotypes, and the increase in length and weight in specimens of the rainbow trout (Oncorhynchus mykiss), resultant from directed mating between homozygous females and heterozygous males according to their NOR phenotypic patterns. The equations of the relationship between length and weight of the analyzed specimens followed the model Wt = a Lt b, showing b values higher than 3, determinant of a positive allometric growth. The results showed that the different NOR phenotypes were not related with the growth values for length and weight in any statistical test.


O crescimento é um dos mais importantes aspectos considerados no melhoramento genético de espécies de peixes cultivadas. Conseqüentemente, a ênfase das pesquisas na área tem sido avaliar os parâmetros genéticos relacionados com esta característica e sua resposta à seleção. Essas pesquisas indicam, em geral, haver variância genética aditiva suficiente para justificar o uso da seleção. Considerando que a utilização de marcadores citogenéticos ou moleculares pode ser de grande valia para a piscicultura, o presente trabalho teve como objetivo analisar a possível relação entre as características citogenéticas, de modo específico os padrões fenotípicos das NORs e o crescimento em comprimento e em peso dos exemplares de trutas arco-íris (Oncorhynchus mykiss) resultantes de acasalamentos dirigidos entre fêmeas homozigotas e machos heterozigotos, conforme caracterização do padrão fenotípico da NOR. As equações da relação comprimento e peso dos indivíduos analisados seguiram o modelo onde Wt = a Lt b, mostrando valores de b maiores que 3, determinante de um crescimento do tipo alométrico positivo. Os resultados mostraram que os padrões fenotípicos da NOR dos indivíduos homozigotos e dos heterozigotos não apresentaram diferenças estatisticamente significativas entre seus valores de crescimento em comprimento ou peso.


Asunto(s)
Animales , Masculino , Femenino , Acuicultura , Región Organizadora del Nucléolo/genética , Oncorhynchus mykiss/genética , Fenotipo , Selección Genética , Aumento de Peso/genética , Análisis Citogenético , Heterocigoto , Homocigoto , Modelos Genéticos , Oncorhynchus mykiss/crecimiento & desarrollo
6.
J Exp Zool ; 287(7): 493-502, 2000 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11110163

RESUMEN

Triploidy was induced in the rainbow trout in order to evaluate whether the altered numbers and sizes of triploid cells could modify fin regeneration. Amputation of one lobe of the tail fin of diploid and triploid juveniles resulted in regeneration for experimentals and controls. Nevertheless, both rate and frequency of regeneration in triploids were significantly increased as compared with diploids, a fact that can be attributed to the increased nuclear and cellular volume in a wide range of tissues, whereas the cell numbers were reduced. These data suggest that a great deal of interesting and important research could be done using triploid animals as experimental models for studying the regeneration of appendages.


Asunto(s)
Oncorhynchus mykiss/fisiología , Ploidias , Regeneración/genética , Animales
7.
Chromosome Res ; 3(3): 182-90, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7780662

RESUMEN

The surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and oocytes of rainbow trout in order to visualize the process of autosome and sex chromosome synapsis in this species. The structure of lateral elements (LEs) of the SC and the chromosome synapsis process at the stages of leptotene, zygotene and pachytene are described. Comparative analysis of SCs of spermatocytes and oocytes showed a difference in the synaptic process, i.e. in spermatocytes all LEs were synapsed before the appearance of centromeric regions in the biarmed elements, while in the oocytes some fully synapsed LEs, including the centromeric region of the biarmed elements, were found together with fully or partially unsynapsed LEs. In males the sex chromosome synapsis starts only after all autosomes have synapsed. Irregular synapses involving three or four LEs were found in 3.4% of the cells analyzed in mid or late zygotene. Multivalents were found in males and females. Some aspects of initial meiotic development and their implications in rainbow trout cytogenetics, genetics and evolution are discussed.


Asunto(s)
Oncorhynchus mykiss/genética , Cromosomas Sexuales/ultraestructura , Complejo Sinaptonémico , Animales , Núcleo Celular/ultraestructura , Cromosomas/ultraestructura , Femenino , Masculino , Microscopía Electrónica , Oocitos/ultraestructura , Tinción con Nitrato de Plata , Espermatocitos/ultraestructura
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