Revision of Condyloderes (Kinorhyncha, Cyclorhagida) including description of Condyloderes shirleyi sp. nov.

The description of a new representative of the species-poor genus Condyloderes Higgins, 1969 from the Northeast Pacific (Alaska) is reported. The analyzed specimens of Condyloderes shirleyi sp. nov. showed a significant variation of numerous morphological characters, along with female-specific traits known also from other congeneric species. These findings stimulated the re-investigation of the type material of the six species of Condyloderes described so far, i.e., C. kurilensis Adrianov & Maiorova, 2016, C. megastigma Sorensen, Rho & Kim, 2010b, C. multispinosus (McIntyre, 1962) Higgins, 1969, C. paradoxus Higgins, 1969, C. setoensis Adrianov, Murakami & Shirayama, 2002, and C. storchi Higgins, 2004 in Martorelli & Higgins, 2004. Our study allowed to reveal various morphological novelties and to emend the diagnosis of these species and of the genus Condyloderes . Furthermore, our analysis led to synonymize C. megastigma with C. setoensis . The results of our investigation about the significant variation in C. shirleyi sp. nov. raise a wider question on species identity within Kinorhyncha, underscoring the necessity, if possible, to describe new species from a higher number of specimens and to concentrate on the morphological variation of the going-to-be-described species.