Anaplectus sudhausi, Jahan & Khan & Mahboob & Tahseen, 2020

Jahan, Rehmat, Khan, Rahmat, Mahboob, Mohammad & Tahseen, Qudsia, 2020, A detailed taxonomic study on two new and one known species of Anaplectus De Coninck & Schuurmans Stekhoven, 1933 (Nematoda: Plectidae), Zootaxa 4877 (2), pp. 329-344 : 330-332

Anaplectus sudhausi sp. nov.

( Figs. 1 , 2 )

Measurements. Table 1 .

Description. Female: Body C-shaped; slightly narrowing in anterior region; ventrally arcuate, more so towards posterior extremity. Outer cuticle annulated, 1.5–2.0 μm thick, annules 0.5 μm wide; inner cuticle not striated. Lat-eral field with two wings, marked by four incisures; starting from the middle or posterior part of corpus region and extending almost up to tail terminus; and about 1/6 th corresponding body diameter wide. Somatic setae not discernible. Sublateral hypodermal glands more or less equally sized, ca 1/5–1/6 of corresponding body diameter, arranged in two rows with opposite or alternate positions (except for the anteriormost three unpaired laterally-placed glands) comprising a total of 120–132 lateroventral and laterodorsal pores on each lateral side. Another set of 5–8 small, unpaired laterodorsal glands, approximately 1/7 th of corresponding body diameter, present on the outer side of subdorsal glands dispersed along the entire body length. First hypodermal gland opening 2–3 μm posterior to amphidial aperture. Lip region truncate, continuous or slightly offset from adjoining body. Lip region consists of six separate leaf-shaped lips interspersed by interlabial liplets; apices of lateral lips appear bifid compared to conical apices of submedians. Labial sensilla indistinct. Cephalic sensilla post-labial, stumpy with wide base ca 2–3 μm long, arising at level of 2 nd or 3 rd annule. Amphidial aperture a transverse slit, located at 8 th or 9 th body annule. First hypodermal gland opens ca 2–3 μm posterior to amphidial opening. Cervical papillae located just posterior to amphid or near to first lateral pore. Stoma comprising of non cuticularised cheilostom with straight walls; Gymnostom shorter than wide, with sclerotized arcuate gymnorhabdia and stegostom surrounded by pharyngeal tissue and subdivided into cylindrical pro-, meso- and metastegostom and posterior narrower telostegostom. Stoma with curved/bent walls in some specimens. Stomal lumen opening into pharyngeal lumen marked by pharyngeal tubes. Pharynx differentiated into anterior corpus, a fairly distinct isthmus and an oval to rhomboid-shaped basal bulb with post-bulbar extension leading to a cardia. Basal pharyngeal bulb 20–24 µm long and 18–19 µm wide in dimension with grinder. Nerve ring encircling the isthmus posterior to corpus, at 57–59% of pharyngeal length. Secretory-excretory pore posterior to nerve ring, at 62–63% of pharyngeal length; duct cuticularised and looped extending to a posteriorly located uninucleate excretory cell. One pair of ovoid pseudocoelomocytes present posterior to cardia. Intestine thin-wailed, granular without distinctly demarcated cells. Rectum thick-walled, shorter than anal body diameter without rectal glands.

Reproductive system didelphic, amphidelphic. Ovaries well developed, reflexed; anterior ovary on right and posterior on left side of intestine. Oocytes arranged in 2–3 tiers distally; spermatheca with globular sperm cells; columella distinct. Intra-uterine eggs 60–62 µm long and 31–34 µm wide in dimension present with spinose shells. Vagina perpendicular to main body axis, with distinct vagina vera and vagina uterina, extending inward 1/3 rd of vulval body diameter; vulval lips slightly protruding; epiptygma absent. Tail conoid, ventrally arcuate, acutely pointed terminally. Three pairs of caudal setae present; caudal glands reduced, opening through a weakly cuticularised spinneret.

Male: Similar to female in general morphology. Reproductive system diorchic, anterior testis outstretched, posterior testis reflexed. Anterior testis and vas deferens on right-hand side and posterior testis on left-hand side of intestine. Three sclerotized preanal tubular supplements or tubuli present: the first one opening at 11–13 µm, the second one at 27–31 µm and the third one 47–51 µm anterior to cloacal opening. Tail short, ventrally arcuate. Spicules arcuate, with oval or round manubrium slightly wider than adjoining calomus or blade. Gubernaculum plate-like with a dorsal projection perpendicular to corpus; large triangular lateral sleeve with a wide base arising from corpus enveloping spicules for about 1/3 rd their length distally and elongated caudal apophyses present. Genital papillae comprising of three precolacals with one ventrolateral pair and a single median papilla close to anterior cloacal lip, five pairs of post cloacal papillae with three lateral in the mid tail region and two subventral pairs close to tail tip.

Type habitat and locality. Soil containing Anaplectus sudhausi sp. nov. was collected from the lawn of Institut für Zoologie, Freie Universitat Berlin, Germany at coordinates N 52° 27’ 33.12”, E 13° 18’ 23.80” .

Type specimens. Holotype female on slide Anaplectus sudhausi sp. nov. GER/1 deposited in the Nematode Collection, Department of Zoology, Aligarh Muslim University, Aligarh. Four paratype females and two paratype males on slides Anaplectus sudhausi sp. nov. GER/2–5 deposited in the Nematode Collection, Department of Zoology, Aligarh Muslim University, Aligarh.

Diagnosis and relationship. Anaplectus sudhausi sp. nov. is characterised by its medium-sized body, with finely annulated cuticle; labial region slightly offset from body contour; amphid located near anterior part of stoma; leaf-shaped lips interspersed by interlabial liplets; lateral lips with bifid apices; cheilostom with non-cuticularised walls; gymnostom with cuticularized, arcuate walls; basal bulb oval to rhomboid; 120–132 sublateral hypodermal glands on each body side with an additional 5–8 smaller subdorsal hypodermal glands; vulval lips protruding; female tail with three caudal setae and a weakly cuticularised spinneret; males with arcuate spicules with manubrium slightly wider than calomus and blade; last median tubulus or supplement about half spicule length; gubernaculum with a dorsal projection perpendicular to corpus; large triangular lateral sleeve and elongated caudal apophyses and tail terminus with a weakly cuticularised spinneret.

Anaplectus sudhausi sp. nov. resembles A. atubulatus in most morphometric details but differs in having an additional row of smaller, subdorsal hypodermal glands (vs additional row not reported), three pairs (vs two pairs) of caudal setae in females; males with gubernaculum having crura or lateral sleeve with a wide base (vs narrow base); closely spaced (vs more widely spaced) tubuli; three precloacal and five pairs of postcloacal (vs three precloacal and seven pairs of postcloacal) genital papillae and spinneret present [vs absent in A. atubulatus ( Holovachov et al. 2004) ].

The new species also resembles A. brzeskii in most of the morphometric details but differs in having an additional row of smaller subdorsal hypodermal glands (vs additional row not reported); males with three precloacal and five pairs of postcloacal (vs one precloacal and thirteen pairs of postclocal) genital papillae and spinneret weak [vs strongly cuticularised in A. brzeskii ( Holovachov et al. 2004) ].

A. sudhausi sp. nov. differs from A. granulosus in having relatively smaller-sized (0.81–0.86 mm vs 0.7–1.5 mm) females; fewer (120–132 vs 160) hypodermal glands; an additional row of smaller, subdorsal hypodermal glands (vs additional row not reported); three pairs (vs four pairs) of caudal setae; males with arcuate spicules with manubrium wider but continuous (vs separated by a notch) with calomus; gubernaculum with prominent (vs weak) conical sleeve; lesser (vs greater) number of genital papillae and spinneret weak [vs strongly cuticularised in A. granulosus ( Allen & Noffsinger 1968, Holovachov et al. 2004)].

The new species further differs from another gonochoristic species, A. varicaudatus in most of the morphometric details but differs in having lateral fields with four (vs three) lines under LM; greater number (120–132 vs 98) of hypodermal glands; an additional row of smaller, subdorsal hypodermal glands (vs additional row not reported); gubernaculum with a conspicuous triangular lateral sleeve or crura and dorsal apophyses [vs lateral sleeve or crura and apophyses not reported in A. varicaudatus ( Allen & Noffsinger 1968) ].

Etymology. The new species is named after Prof. Walter Sudhaus acknowledging his valuable contributions to nematode systematics.

Figures

FIGURE 1. Anaplectus sudhausi sp. nov. A: Entire female. B: Anterior end. C: Female pharyngeal region D: Female reproductive system. E: Female posterior region. F: Male posterior region.

FIGURE 2. A. sudhausi sp. nov. A: Anterior end (SEM). B: Anterior end LM). C: En face view. D: Neck region (SEM). E: Anterior Pharyngeal region (LM). F: Posterior pharyngeal region. G: Body region with lateral field. H, I: Female posterior region (SEM). J: Male posterior region (SEM). K, L: Male posterior region (LM) (Scale bars = 10 μm).