“…Recently, numerous molecular phylogenetic studies on earthworms have been conducted (Jamieson et al, 2002;Pop et al, 2003Pop et al, , 2007Heethoff et al, 2004;Pérez-Losada et al, 2005Chang et al, , 2007Chang et al, , 2008Chang et al, , 2009Admassu et al, 2006;Huang et al, 2007;King et al, 2008;Cameron et al, 2008;Minamiya et al, 2009;Richard et al, 2009;Novo et al, 2009Novo et al, , 2010Knott and Haimi, 2010). Many of these studies used the mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) gene (Pop et al, 2003(Pop et al, , 2007Pérez-Losada et al, 2005Admassu et al, 2006;Chang et al, 2007Chang et al, , 2008Chang et al, , 2009Huang et al, 2007;King et al, 2008;Cameron et al, 2008;Minamiya et al, 2009;Rougerie et al, 2009;Novo et al, 2009Novo et al, , 2010Knott and Haimi, 2010) because of the ease of primer design and the range of phylogenetic signals and rapid evolutionary rate of this gene (Hebert et al, 2003). To clarify the phylogenetic relationships of A. vittatus with different degree of degraded reproductive organs, we examined the morphological variations, such as the possession rate of both the male and spermathecal pores in A. vittatus found in various locations in Sendai city around Mt.…”