Estudios citogenéticos en teleosteos marinos y dulceacuícolas de venezuela
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Data
2009-10-23
Autores
Nirchio T. , Mauro [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
La determinación del numero diploide (2n), la fórmula cariotípica y el Número Fundamental (NF) para 68 especies marinas y 26 dulceacuícolas pertenecientes a 39 familias contenidas en 18 ordenes reveló que el número diploide varió entre 2n=24 en Mugil curema (Mugilidae) y 2n=60 para Pygocentrus cariba, Serrasalmus rhombeus (Characidae) y Hoplosternum littorale (Callichthyidae) con una moda de 48 cromosomas representada en 47,3% (43/91) de todas las especies estudiadas. El porcentaje de especies que posee exclusivamente 48 cromosomas acrocéntricos (a) fue de 29,67% (27/91) y el NF varió entre 33/34 en Stephanolepis setifer (Tetraodontiformes) a 110 en Pygocentrus cariba y Serrasalmus rhombeus (Characiformes). En el grupo de peces marinos, el número diploide modal fue 48 y estuvo representado en 66,6% de todas las especies estudiadas, mientras que en los peces dulceacuícolas el complemento diploide modal fue 2n=54 representado en 30% de las especies estudiadas. La mediana del número de cromosomas fue estadísticamente mayor en los peces dulceacuícolas que en los marinos. EI el range medio del NF fue superior en el grupo de peces dulceacuícolas indicando que el grade de variación cariotípica, fue mayor en peces de aguas continentales en contraste con un patrón citogenético más conservado en los peces marinos. La proporción de especies con 48 cromosomas exclusivamente acrocéntricos predominó en el 36,7% de los peces marinos mientras que en los dulceacuícolas apenas alcanzó el 7,7%. Al comparar los Perciformes (linaje compuesto principalmente por peces marinos y uno de los más derivados en la filogenia de los Actinoperygii) contra el resto de los órdenes, se verificó que en aquellos, el 61,54% de las especies analizadas exhibieron cariotipos con 48 cromosomas a. AI graficar el número diploide de cromosomas y el NF contra la ordenación filogenética propuesta... (Resumen completo clicar acceso eletronico abajo)
Diploid number (2n), Karyotype formula and the fundamental number (NF) for 94 fish species, 68 marine and 26 freshwater species from 39 families contained in 18 orders revealed that the diploid number ranged between 2n = 24 in Mugil curema (Mugilidae) and 2n=60 for Pygocentrus cariba, Serrasalmus rhombeus (Characidae) and Hoplosternum littorale (Callichthyidae) with a mode of 48 chromosomes represented in 47.3% (43/92) of all studied species. The percentage of species with exclusively 48 acrocentric chromosomes was 29.67% (27/91) and the NF ranged from 33-34 in Stephanolepis setiter (Tetraodontiformes) to 110 in Pygocentrus cariba and Serrasalmus rhombeus (Characiformes). In the marine fish group the mbdal diploid number was 48 and was represented in 66.6% of all studied species, whereas in the freshwater fishes modal diploid complement was 2n=54 represented in 30% of the studied species. The median of the number of chromosomes was statistically higher in freshwater fishes than saltwater fishes. The NF was higher in the group of freshwater fishes indicating that the degree of karyotipic variation was greater in fish of inland waters in contrast with a more conserved cytogenetic pattern in the marine fishes. The proportion of species with 48 exclusively acrocentric chromosomes predominated in 36.7% of the marine fishes while it barely reached 7.7% in freshwater fishes. Comparing the Perciformes (a lineage composed mainly of marine fish and one of the most derived in the Actinoperygii phylogeny of the) against the rest of the orders, it was verified that in Perciformes 61.54% of analyzed species exhibited karyotypes with 48 chromosomes. When diploid number of chromosomes and the NF were plotted against the phylogenetic arrangement proposed by NELSON (2006) for actinopterigian fishes, both plottings revealed an inversely proportional relationship with values close to 60 in most ancestral... (Complete abstract click electronic access below)
Diploid number (2n), Karyotype formula and the fundamental number (NF) for 94 fish species, 68 marine and 26 freshwater species from 39 families contained in 18 orders revealed that the diploid number ranged between 2n = 24 in Mugil curema (Mugilidae) and 2n=60 for Pygocentrus cariba, Serrasalmus rhombeus (Characidae) and Hoplosternum littorale (Callichthyidae) with a mode of 48 chromosomes represented in 47.3% (43/92) of all studied species. The percentage of species with exclusively 48 acrocentric chromosomes was 29.67% (27/91) and the NF ranged from 33-34 in Stephanolepis setiter (Tetraodontiformes) to 110 in Pygocentrus cariba and Serrasalmus rhombeus (Characiformes). In the marine fish group the mbdal diploid number was 48 and was represented in 66.6% of all studied species, whereas in the freshwater fishes modal diploid complement was 2n=54 represented in 30% of the studied species. The median of the number of chromosomes was statistically higher in freshwater fishes than saltwater fishes. The NF was higher in the group of freshwater fishes indicating that the degree of karyotipic variation was greater in fish of inland waters in contrast with a more conserved cytogenetic pattern in the marine fishes. The proportion of species with 48 exclusively acrocentric chromosomes predominated in 36.7% of the marine fishes while it barely reached 7.7% in freshwater fishes. Comparing the Perciformes (a lineage composed mainly of marine fish and one of the most derived in the Actinoperygii phylogeny of the) against the rest of the orders, it was verified that in Perciformes 61.54% of analyzed species exhibited karyotypes with 48 chromosomes. When diploid number of chromosomes and the NF were plotted against the phylogenetic arrangement proposed by NELSON (2006) for actinopterigian fishes, both plottings revealed an inversely proportional relationship with values close to 60 in most ancestral... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Peixe de agua doce, Peixe de água marinha, Citogenetica, Evolução, Fresh water fish, Cytogenetics
Como citar
NIRCHIO T. , Mauro. Estudios citogenéticos en teleosteos marinos y dulceacuícolas de venezuela. 2009. 225 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2009.