Redescription of a predatory and cannibalistic nematode, Butlerius butleri Goodey, 1929 (Rhabditida: Diplogastridae), from South Africa, including its first SEM study

Abstract

Summary Butlerius butleri was isolated during a survey on free-living soil nematodes from South Africa. The South African population of B. butleri is characterised by having a large stoma divided into two chambers and bearing a thorn-like dorsal tooth, spicules 44 (41-49) μm long, gubernaculum 29 (28-30) μm long, three pairs of precloacal papillae and five pairs of postcloacal papillae, and a filiform tail 280 (204-332) μm long in females, 310 (256-356) μm long in males. The SEM observation showed the cheilostom is divided into six conical plates 2.1-2.3 μm long. Nblast of 18S rDNA revealed 99% similarity and 6-7 bp differences with the B. butleri (KP453998) from Iran. Molecular analysis of B. butleri based on the sequence of the 18S and 28S rDNA placed it together with Butlerius and close to Pseudodiplogasteroides and Diplogasteroides. This species showed predatory and cannibalistic behaviours, feeding on other B. butleri in the substrate. SEM photographs of the species are presented for the first time.