The first record and description of females of the genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) from the South Shetland Islands

Abstract

There is a single record of the rare terrestrial nematode genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) in the type locality on Chiloé Island (South Chile). The type species of the genus, Acunemella torta Andrássy, 2002, was described on the basis of only two male specimens. In this article, mature females of the genus Acunemella are described for the first time based on morphology and morphometrics of specimens from Deception Island (South Shetland Islands). The current article is the first report of this genus from the Antarctic region. Females from Deception Island are characterized by a didelphic-amphidelphic genital system, with both branches almost equally developed, a distinct muscular sphincter between oviduct and uterus, a curling outer surface of the uterus, pars refringens vaginae moderately sclerotized, with two relatively large (4–6 × 12–13 μm) rounded triangular pieces, a vulval region with well-developed cuticular folds. Morphologically, females are similar to originally described males but differ by longer bodies, more distinctly offset lip regions and the shape of sperm cells in uterus. Verifying the taxonomic status of the population described in this article requires the analysis of additional materials.

Keywords

• antarctica
• deception island
• morphology
• nematodes
• taxonomy