Studies on The Karyotypes of Birds Ⅻ.The 12 Species of Passeriformes

The karyotypes of 12 species of belonging to Passeriformes were studied from bone marrow cells with colohicine-hypotonic air-drying technique.Diploid numbers and chromosome morphology of related species previouly studied are compared with the results of the present study.Karyotype of all the studied species have considerable similarities in the whole appearance and size grouping of the chromosomes wihtin the karyotype,but defailed morphological analysis shows a difference among the karyotypes of the different species.Within the Alaudidae (Larks) Dipoid numbers range from 72 to 80,but it is probable that this largely reflects difficulties in accurately counting the number of microchromosomes.The Z-and W-chromosomes are the largest elements and are metacentric and submetacentric respectively.Centric fissinons or reciprocal translocations involving macro- and microchromosomes might have contributed to the reduction in the number of macroautosomes in these genera.