| sympatric occurrence of three cytotypes and four morphological types of b chromosomes of astyanax scabripinnis (pisces, characiformes) in the river ivaí basin, state of paraná, brazil. | chromosomes of astyanax scabripinnis from the tatupeba stream, ivaí basin (state of paraná, brazil), were analyzed. astyanax scabripinnis population presents 3 different diploid numbers (2n = 46, 48 and 50) and b chromosomes in each cytotype. eighty per cent of the females among individuals of cytotype i (2n = 50) has a metacentric b macrochromosome, whereas three different types of b chromosomes were identified in individuals of cytotype ii (2n = 48). cytotype iii (2n = 46) showed two b chromos ... | 2005 | 16134341 |