Morphological and molecular characterisation of Aporcelaimellus simplex (Thorne & Swanger, 1936) Loof & Coomans, 1970 and a new concept for Aporcella Andrássy, 2002 (Dorylaimida: Aporcelaimidae)

Abstract

This contribution presents a study of Iberian and Californian populations of Aporcelaimellus simplex , including morphological, morphometric and molecular data. The species is characterised and distinguished by its lip region offset by an expansion, pars refringens vaginae absent, and conical tail with a small but distinct hyaline terminal portion. No significant difference exists between American and European populations. Molecular data and the derived evolutionary tree show a topology in which this species forms a well-supported group with members of Discolaiminae, far from other representatives of Aporcelaimellus. Putting special emphasis in the absence of pars refringens vaginae , A. simplex is transferred to the genus Aporcella . The taxonomy of this genus is revised in depth, with the proposal of an emended diagnosis, the provision of a list of 13 valid species (mostly new combinations from Aporcelaimellus ) as well as a key to their identification and a compendium of their main morphometrics. Aporcella debruinae sp. n. is proposed for Aporcelaimellus papillatus apud de Bruin & Heyns, 1992.