Morphological Characterization of Fresh and 20-Yr-Old Fixed Nematode Specimens of Sauertylenchus Maximus (Allen, 1955) Siddiqi, 2000 Deposited in the USDA Nematode Collection from Arlington National Cemetery, VA, USA

J Nematol. 2022 Oct 19;54(1):20220041. doi: 10.2478/jofnem-2022-0041. eCollection 2022 Feb.

Abstract

Sauertylenchus maximus was discovered during a survey conducted at the Arlington National Cemetery, Virginia, for the type specimens of Hoplolaimus galeatus. Besides the fresh material, the fixed specimens of S. maximus were also studied by molecular and morphological means. The morphological and morphometric characteristics of the recovered fresh material were consistent with the original and other description(s) of this species. The fixed specimens used in this study were preserved in a 3% formaldehyde and 2% glycerin solution for over 20 yr. Molecular analyses of the fresh and fixed specimens were performed using internal transcribed spacer, D2-D2 expansion segments of 28S large subunits, and 18S small subunit ribosomal DNA sequences. To our knowledge, this represents the first report of S. maximus from Virginia and the first report of a successful DNA extraction from fixed nematode specimens.

Keywords: 18S rDNA; 28S rDNA; ITS rDNA; Sauertylenchus maximus; USDANC; fixed specimens; taxonomy.