Cytogenetic description of the earthworm Drawida ghilarovi Gates, 1969 (Oligochaeta, Moniligastridae) from the southern Russian Far East.

Galina V Roslik,Gennady N Ganin,Alim P Anisimov

doi:10.3897/compcytogen.v9i4.5741

Abstract

Sixty-six specimens of the earthworm Drawida ghilarovi Gates, 1969 (Oligochaeta, Moniligastridae) from 15 localities of the southern Russian Far East were studied cytogenetically. We examined chromosome sets during mitosis and diakinesis as well as DNA content in the spermatogenous and somatic cell nuclei. The populations and morphs displayed no differences in karyotype and ploidy levels estimated in terms of both chromosome number and DNA mass index: n = 10, 2n = 20; c = 1.1 pg, 2c = 2.2 pg. We conclude that polyploidy as a species- or race-forming factor is not typical of these earthworms.

Highlights

The karyology of Oligochaeta is mainly studied in the earthworms of the family Lumbricidae
The goal of the present study is to describe the karyotype and determine the ploidy levels in geographically remote D. ghilarovi populations from various biotopes of the northern, western, southern, and eastern parts of the species’ Far Eastern range
Specimens of D. ghilarovi were collected in fifteen localities of the southern Russian Far East (Fig. 1, Table 1)

Summary

Introduction

The karyology of Oligochaeta is mainly studied in the earthworms of the family Lumbricidae. A distinctive feature of the evolution of their karyotypes is polyploidy, which is widespread in the family. The polyploid races and subspecies occur as frequently as the diploid ones (Bulatova et al 1987, Perel 1987, Viktorov 1993, 1997, Kashmenskaya and Polyakov 2008, Garbar et al 2009, Vlasenko et al 2011). Di- and polyploid forms tend to be spatially isolated, with the latter occurring predominantly at the edges of the species’ ranges (Grebelnyi 2008, Kotsyuba et al 2010, Onyschuk and Garbar 2010). It was shown that polyploidy is not the cardinal mechanism of the microevolution of the lumbricid species and subspecies in the Caucasus (Bakhtadze et al 2008)

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