Three uncharted endemic earthworm species of the genus Eutyphoeus (Oligochaeta: Octochaetidae) from Mizoram, India.

Abstract

Integrative approach of taxonomy drives us to the discovery of three new species of the genus Eutyphoeus Michaelsen 1900, namely Eutyphoeus phawngpuiensis sp. nov., Eutyphoeus serei sp. nov. and Eutyphoeus tawi sp. nov. from protected forests of Mizoram, India. E. phawngpuiensis sp. nov. belongs to the Eutyphoeus hastatus group, and is characterized by holandric male organs, having spermathecal pores at a or ab, bidiverticulate spermathecae, and lack of genital marking glands. While, E. tawi sp. nov. has spermathecal pores at b or lateral to b, without lateral intestinal caeca. E. serei sp. nov. belongs to the Eutyphoeus gigas group, and is distinguished by having metandric male organs, lacking female pore of right side, and having spoon shaped tip of penial setae without ornamentation. Molecular characterization using coi gene marker also supports the findings. The maximum intraspecific distances and distance to the nearest neighbour of E. phawngpuiensis sp. nov., E. serei sp. nov. and E. tawi sp. nov. were recorded 3.5%, 9.37%; 2.35%, 14.83%; and 2.28%, 12.86% respectively. The key to Eutyphoeus species of India was also updated.