Necturus Chromosome Evolution 



43 



10 



QfiSs e 



§s 



SSSSBSsss 



12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 



B 

 10 \ 



fiflSUSQ 



55§s 



10 



X 



X i 



S^gft 



SB8§sass 







D 



10 



% 



XX 



12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 



Fig. 3. Idiograms of Necturus species showing four kinds of karyotypes found 

 in the genus. A, N. lewisi; B, N. punctatus; C. N. alabamensis; D, N. maculosus. 

 Dark regions and lines represent C-band heterochromatin. Stippled areas on 

 Y-chromosomes represent light staining C-band heterochromatin. Presumed 

 homologous chromosomes are connected by dashed lines between idiograms. 



