Acrobeloides bodenheimeri ( Steiner, 1936 ) Thorne, 1937

Kim, Taeho & Park, Yucheol Lee and Joong-Ki, 2021, First report and morphological description of two Acrobeloides species (Nematoda: Rhabditida: Cephalobidae) in South Korea, Journal of Species Research 10 (4), pp. 405-411 : 406-408

Acrobeloides bodenheimeri ( Steiner, 1936) Thorne, 1937 ( Table 1, Fig. 1 )

Ṟffi꼬Ḩẘfflḏẃflệ (ljḍ)

Acrobeles bodenheimeri : Steiner, 1936: 77, fig. 24. Cephalobus bodenheimeri : Andrássy, 1984: 170. Rafiqius bodenheimeri : Khan and Hussain, 1997: 140. Acrobeloides rotundifolius : Bussau, 1991: 122, abb. 7. Acrobeloides bodenheimeri : Thorn, 1937: 11.

Material examined. 1$, Buk-myeon , Uichang-gu, Changwon-si, Gyeongsangnam-do, South Korea (GPS coordinates: 35°22′22.5″N, 128°36′47.3″E) , extracted by sieving and the Baermann funnel method from potato farm soil. The specimen (slide No. NIBRIV0000862892) is deposited at the National Institute of Biological Resources , South Korea .

Measurements. See Table 1.

Description. Female: Body cylindrical, length 529.5 μm long, ventrally curved after fixation ( Fig. 1A ). Cuticle annulated; annuli 2.0 μm wide and 1.0 μm thick at mid-body. Lateral field occupying 22.2% of width of body at mid-body. Lateral incisures varying in number along body length: three incisures between procorpus region and deirid, branching off from deirid into five incisures ( Fig. 1B ); two incisures fading out between anus and phasmid region; three incisures extending to tail terminus ( Fig. 1C ). Head region continuous with neck. Lip region 7.5 μm in diameter, with triradiate symmetry with 6 + 4 papillae ( Fig. 1D ). Three pairs of asymmetrical lips; pairs of lips separated by U-shaped primary axils. Guarding process absent. Cephalic probolae absent. Three low and rounded labial probolae present. Stoma cephaloboid; length 1.6 times the lip region diameter ( Fig. 1B ). Cheilorhabdions oval-shaped. Small dorsal denticle on metastom. Pharyngeal corpus fusiform with swollen metacorpus, 3.1 times isthmus length. Isthmus narrower than corpus, distinctly demarcated from metacorpus. Basal bulb oval-shaped with well-developed valves; 1.4 times as long as its width. Cardia inconspicuous, surrounded by intestinal tissue. Nerve ring located in posterior corpus, at 63.7% of pharynx length. Excretory pore position at posterior corpus, at 63.8% of pharynx length. Position of deirids in lateral field at anterior isthmus, at 71.5% of total neck length. Reproductive system monodelphic-prodelphic ( Fig. 1E ). Vulva lips not protruding. Vagina length 0.6 times body diameter. Post-uterine sac 2.6 times body width. Uterus length 3.2 times body diameter. Spermatheca 1.9 times body width. Oviduct short. Ovary straight, with a single row of oocytes. Rectum length 1.5 times anal body diameter ( Fig. 1C ). Tail conoid, with truncated terminus. Phasmids located middle of tail, at 48.1% of tail length.

Male: Unknown.

Distribution. Denmark ( Bussau, 1991), Israel ( Steiner, 1936), Mongolia ( Andrássy, 1967), Malawi ( Siddiqi et al., 1992), South Korea (this study), Spain ( Abolafia and Peña-Santiago, 2003), and USA ( De Ley et al., 1999).

Habitat. Soil sample from a potato farm.

Remarks. Morphological characters of the specimen described in this study generally agree with previous studies ( Steiner, 1936; Siddiqi et al., 1992; De Ley et al., 1999; Abolafia and Peña-Santiago, 2003), except for total body length (529 vs 613-1,530 μm), the ratio of body length to body width (a = 27.2 vs 15.0-24.3), the ratio of total body length to pharynx length (b = 3.4 vs 4.0-7.8) and corpus to isthmus ratio (3.1 vs 3.3-7.2). Although these morphometric measurements of the specimen examined from a single individual differ from A. bodenheimeri , they are considered intraspecific variations as previously reported from many other Acrobeloides species ( Anderson, 1965; 1968; Boström and Gydemo, 1983; De Ley et al., 1999; Abolafia and Peña-Santiago, 2003). Morphometric analysis using multiple nematode individuals is further required to delimitate morphological variation of the species.

Figures

Fig. 1. Acrobeloides bodenheimeri (Steiner, 1936) Thorne, 1937. A, Entire female; B, Female neck region; C, Female posterior region; D, Female head region; E, Female reproductive system. am, amphid; an, anus; bb, basal bulb; ca, cardia; co, corpus; cpa, cephalic papilla; de, deirid; ep, excretory pore; in, intestine; is, isthmus; lf, lateral field; lpa, labial papilla; lpr, labial probolae; nr, nerve ring; ovi, oviduct; ova, ovary; pa, primary axil; ph, phasmid; pus, post-uterine sac; re, rectum; spe, spermatheca; st, stoma; ut, uterus; va, vagina; vu, vulva.