3.2 cox1 haplotype network
A total of 37 haplotypes were detected in S. lomentaria , and these haplotypes formed three haplogroups (group A–C; Figure 2). Group A had 26 haplotypes and was detected throughout Japan, Europe, North America (both Pacific and Atlantic coasts), and Argentina. Group B had six haplotypes and was detected in the Sea of Japan coast of southern Honshu and North America. Group C had five haplotypes and was detected from the Pacific coast of central Honshu. Samples of parthenogenetic populations in Japan had group A haplotypes without exception. Most haplotypes from Europe, North America, and Argentina were identical or close to those from parthenogenetic populations from Japan and formed a big star-like network pattern (i.e., one frequent haplotype together with several less frequent haplotypes). Group A included haplotypes which did not found in male samples (haplotypes indicated by arrowheads in Figure 2).