Figure 4. The standard and Em karyotypes of three species groups; grammicus, megalepidurus, and asper. S. mucronatus of the torquatus group is also illustrated to allow convenient comparison. The Em karyotypes differ from standard only by the relative enlargement of pair 9, which is indicated by the black border. A. S. mucronatus ♂ (F6202). B-D are all grammicus group: B S. grammicus ♂ (F5691), C. S. shannorum ♂ (F5065), D. S. heterolepis ♀ (5829). E and F are megalepidurus group: E. S. pictus ♂ (Y25591), F. S. megalepidurus ♂ (F6200). Asper group: G. S. asper ♂ (F5809). The central bar represents 10 micrometers.