Biogeography and karyotypes of freshwater planarians (Platyhelminthes, Tricladida, Paludicola) in southern Brazil.
Zoolog Sci
; 24(2): 123-9, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17409725
ABSTRACT
In the Tricladida (Platyhelminthes), the incidence of different biotypes identified by several ploidy levels is very common. Planarians collected in the State of Rio Grande do Sul were identified using cytogenetics. Different species distributions were observed with respect to Rio Grande do Sul's geomorphology, which could have been caused by their different microhabitats. Girardia tigrina and G. anderlani consisted of diploid and triploid individuals, whereas G. schubarti showed diploids, triploids, and mixoploids; for all these species, individuals of different ploidies were sympatric. Only for diploid G. anderlani were B chromosomes observed. These B chromosomes seem to have an irregular segregational behavior during mitosis, and possibly also during meiosis. However the processes (e.g., selection, mutation) of maintaining 2n, 3n, and 2n/3n individuals within natural populations of G. schubarti remain to be clarified.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Planárias
/
Cromossomos
Limite:
Animals
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article