Differentiation within the Drawida ghilarovi complex (Moniligastridae: Annelida) revealed by multigene transcriptomic dataset analysis

Abstract

Drawida ghilarovi is an earthworm species with the northernmost distribution of all Monilidastridae in Asia. It includes multiple color morphs and has significant genetic diversity. In this study we used transcriptome sequencing to demonstrate that D. ghilarovi consists of three genetic clades that differ on both mitochondrial and nuclear genome levels. Pigmentation in D. ghilarovi appears to be labile, with frequent switching between different morphs. One of the clades of the complex is known from grey morphs only, the other consists of both grey and brown morphs, and the third one also has populations with black pigmentation. Two of the three clades are found only in the very south of the Russian Far East, while the third one has a distribution area that extends 800 km to the north, with the northernmost part of the distribution occupied by the black morph. We demonstrated that it would be phylogenetically unreasonable to divide the complex according to pigmentation, but splitting it according to genetic clades could be sensible.