Mya truncata

MYA TRUNCATA View in CoL MAY REFLECT A SPECIES COMPLEX

The ABGD analysis indicated that M. truncata was a candidate species complex ( Fig. 5C View Figure 5 ), which included two distinct groups (ABGD Groups 3 and 4; Table 3). The COI genetic distances between individuals of these groups ranged from 6.93 to 7.26% ( Table 3). While these are intermediate values between the maximum intraspecific p -distance (1.70%) within M. japonica + M. arenaria and the minimum interspecific p -distance (10.68%) among the other Mya species, this may reflect a true species-level difference, which is consistent with Petersen (1999) and Layton et al. (2014). At present, we are unable to fully resolve the taxonomic status of M. truncata . All the M. truncata COI sequences examined in this study were obtained from individuals collected in Nunavut, Canada ( Layton et al., 2014). However, individuals in ABGD Group 3 were collected near Cornwallis Island, whereas individuals in ABGD Group 4 were collected around Igloolik Island, indicating possible spatial structure to the putative species complex. Specimens collected from the entire range of M. truncata (eastern Pacific, Arctic and northern Atlantic) and additional data (e.g. spermatozoan ultramorphology) are needed to clarify the taxonomic status of M. truncata .