Journals / Turkish Journal of Zoology / 2012 / Cilt: 36 - Sayı: 1

Microtaxonomy of fragmenting Enchytraeus species using molecular markers, with a comment on species complexes in enchytraeids

Pages
85–94
DOI
—

Abstract

Populations of Enchytraeus that reproduce by fragmentation are distributed worldwide, but their species-level taxonomy is unresolved because morphological differences are inconclusive. Therefore, we compared the isozyme and RAPD-PCR patterns of 5 populations of fragmenting enchytraeids from widely distant localities (Japan, Iran, Greece, and Brazil). Among these populations, 3 were identified (E. japonensis, E. bigeminus, and E. dudichi) and 2 were unidentified. Multiple isozyme bands suggested polyploidy in all investigated populations. In all RAPD-PCR algorithms except 1, the fragmenting group formed a cluster separate from 2 nonfragmenting Enchytraeus species. All 5 populations were clearly separable on the levels of protein and DNA, but the unidentified Greek populations clustered more closely with E. japonensis. It remains unknown whether the fragmenting group in Enchytraeus is monophyletic or polyphyletic. Although every investigated population may deserve species rank, a consistent classification is impossible at present.

Özet

Populations of Enchytraeus that reproduce by fragmentation are distributed worldwide, but their species-level taxonomy is unresolved because morphological differences are inconclusive. Therefore, we compared the isozyme and RAPD-PCR patterns of 5 populations of fragmenting enchytraeids from widely distant localities (Japan, Iran, Greece, and Brazil). Among these populations, 3 were identified (E. japonensis, E. bigeminus, and E. dudichi) and 2 were unidentified. Multiple isozyme bands suggested polyploidy in all investigated populations. In all RAPD-PCR algorithms except 1, the fragmenting group formed a cluster separate from 2 nonfragmenting Enchytraeus species. All 5 populations were clearly separable on the levels of protein and DNA, but the unidentified Greek populations clustered more closely with E. japonensis. It remains unknown whether the fragmenting group in Enchytraeus is monophyletic or polyphyletic. Although every investigated population may deserve species rank, a consistent classification is impossible at present.

Keywords: Key words: Cryptic species, molecular diversity, Enchytraeidae, Oligochaeta, Clitellata, Annelida, Enchytraeus bigeminus group

Microtaxonomy of fragmenting Enchytraeus species using molecular markers, with a comment on species complexes in enchytraeids — AJIndex