Parthenogenesis in two Taiwanese mountain earthworms Amynthas catenus Tsai et al., 2001 and Amynthas hohuanmontis Tsai et al., 2002 (Oligochaeta, Megascolecidae) revealed by AFLP

Abstract: Parthenogenesis has been known in a variety of animal taxa and is commonly found in oligochaetes. Many pheretimoid earthworms in Megascolecidae have been known to be or suspected to be parthenogenetic, but there has not been any genetic investigation on them. Amynthas catenus and Amynthas hohuanmontis are earthworms belonging to the Pheretima complex of the family Megascolecidae. Both are endemic to Mt. Hohuan at an elevation of about 3000 m in central Taiwan, and both have spermathecae from three pairs in segments VI–VIII (sexthecal) to absence (athecal) and reproductive organs in different degrees of degeneration. Here we present the genetic evidence revealed by amplified fragment length polymorphism (AFLP) markers to confirm the parthenogenetic mode of reproduction in A. catenus and A. hohuanmontis. Sixty-two selective primer combinations were used to generate a total of 4593 and 4812 bands for A. catenus and A. hohuanmontis, respectively. We found that the two earthworms are automictic (meiotic) parthenogens with offsprings showing slightly reduced number of AFLP markers compared with their parents. There was no sperm in any of the spermathecae examined. Selection and reproductive success among different genotypes of the two earthworms will be an important topic for future investigation. [Copyright &y& Elsevier]