Chokwenema lepidophorum, Morffe, Jans & Garcia, Nayla, 2013

Morffe, Jans & Garcia, Nayla, 2013, Batwanema gen. n. and Chokwenema gen. n. (Oxyurida, Hystrignathidae), new nematode genera as parasites of Passalidae (Coleoptera) from the Democratic Republic of Congo, ZooKeys 361, pp. 1-13 : 6-8

Chokwenema lepidophorum sp. n. Figure 3 A–H, 4 A–C

Type material.

♀ holotype, Democratic Republic of Congo, Ituri province, Mongwalu; in Didimoides cf. parastictus.; 5.VI.1939; Lepersonne coll.; CZACC 11.4708. Paratypes: 3 ♀♀, same data as holotype, CZACC 11.4709-11.4711; 4 ♀♀, same data as holotype, RMCA; 1 ♀♀, same data as holotype, CHIOC.

Additional material.

Vouchers: 3♀♀, Democratic Republic of Congo, Ituri province, Mongwalu; in Pentalobus barbatus ; 5.VI.1939; Lepersonne coll.; CZACC 11.4712-11.4714; 2♀♀, same data as the latter, RMCA; ♀, same data as the latter, RIT821.

Measurements.

Holotype (female) a = 11.65, b = 5.25, c = 13.40, V% = 55.97, total length = 2.680, maximum body width = 0.230, first cephalic annule ( length×width) = 0.018 × 0.063, stoma length = 0.038, procorpus length = 0.400, isthmus length = 0.025, diameter of basal bulb = 0.090, total length of oesophagus = 0.510, nerve ring to anterior end = 0.260, excretory pore to anterior end = 0.720, anus to posterior end = 0.200, eggs = 0.093 –0.098×0.038– 0.040 (0.095 ± 0.003 × 0.039 ± 0.001 n = 3).

Paratypes (females) (n = 8) a = 9.09-15.63 (10.87 ± 2.40 n = 6), b = 4.26-4.90 (4.62 ± 0.28 n = 5), c = 11.68-12.53 (12.04 ± 0.36 n = 4), V% = 54.40-57.75 (55.76 ± 1.24 n = 6), total length = 2.000-2.500 (2.192 ± 0.181 n = 6), maximum body width = 0.160-0.225 (0.209 ± 0.021 n = 8), first cephalic annule ( length×width) = 0.015 –0.020×0.058– 0.063 (0.018 ± 0.002 × 0.060 ± 0.002 n = 6), stoma length = 0.030-0.040 (0.035 ± 0.004 n = 7), procorpus length = 0.330-0.420 (0.376 ± 0.032 n = 7), isthmus length = 0.023-0.038 (0.027 ± 0.006 n = 5), diameter of basal bulb = 0.088-0.100 (0.093 ± 0.005 n = 8), total length of oesophagus = 0.450-0.520 (0.487 ± 0.026 n = 6), nerve ring to anterior end = 0.210-0.260 (0.235 ± 0.021 n = 4), excretory pore to anterior end = 0.660, anus to posterior end = 0.170-0.210 (0.184 ± 0.019 n = 4), eggs = 0.090 –0.100×0.038– 0.050 (0.097 ± 0.004 × 0.043 ± 0.004 n = 11).

Specimens from

Pentalobus barbatus . Females (n = 6) a = 10.36-15.00 (13.25 ± 1.85 n = 6), b = 4.94-5.80 (5.41 ± 0.31 n = 6), c = 13.35-15.73 (14.21 ± 0.95 n = 6), V% = 51.31-56.99 (53.49 ± 2.40 n = 5), total length = 2.175-2.720 (2.453 ± 0.228 n = 6), maximum body width = 0.170-0.210 (0.187 ± 0.016 n = 6), first cephalic annule ( length×width) = 0.015 –0.018×0.048– 0.058 (0.016 ± 0.001 × 0.053 ± 0.004 n = 6), stoma length = 0.033-0.038 (0.036 ± 0.002 n = 6), procorpus length = 0.310-0.390 (0.353 ± 0.027 n = 6), isthmus length = 0.018-0.033 (0.025 ± 0.006 n = 5), diameter of basal bulb = 0.083-0.103 (0.091 ± 0.007 n = 6), total length of oesophagus = 0.410 -0.490 (0.453 ± 0.029 n = 6), nerve ring to anterior end = 0.210-0.250 (0.228 ± 0.015 n = 5), anus to posterior end = 0.150-0.200 (0.173 ± 0.022 n = 6), eggs = 0.088 –0.100×0.035– 0.050 (0.095 ± 0.004 × 0.042 ± 0.004 n = 10).

Description.

Female body robust, widening from the base of the first cephalic annule, maximum body diameter at level of the vulva, then tapering towards anus. Cuticle markedly annulated in the spiny region, annuli less marked in the rest of the body (ca. 3-5µm). Cervical cuticle armed initially by opposite rows of rectangular scales, arranged in number of eight. Scales bifurcate gradually at the third row by a cleavage. Division is total at level of the fifth row, with 16 shorter scales, their tips rounded. Scales becoming pointed towards the end of the spiny region. Last rows of spines (a total of 35-36) end at about one seventh of the body-width before the base of the procorpus. Sub-cuticular longitudinal striae present. Lateral alae absent. Head bearing eight rounded, paired papillae. Amphids lateral, pore-like. First cephalic annule similar in length to head, cone-like, truncated, slightly inflated. Stoma short, about two first cephalic annule-lengths long, surrounded by an oesophageal collar. Oesophagus consisting of a muscular, sub-cylindrical procorpus, its base well set-off from the short isthmus. Basal bulb pyriform, valve-plate well developed. Intestine simple, sub-rectilinear. Rectum short, anus not prominent. Nerve ring encircling the procorpus at ca. 55% of its length. Excretory pore located at ca. three fourths of the body-width posterior to the basal bulb. Vulva a median transverse slit, displaced to the posterior half of body, its lips slightly prominent. Vagina muscular, directed forwardly. Genital tract didelphic-amphidelphic, both ovaries reflexed. Oocytes in single rows. Eggs comparatively small, ovoid, with eight rough longitudinal ridges in the shell. Tail short, conical, subulate, ending in a sharp tip. Male unknown.

Discussion.

Chokwenema gen. n. resembles the African genus Batwanema gen. n. by having a similar arrangement of the cervical spines: first row of eight rectangular scales gradually bifurcating, turning into pointed spines. The genus differs by its genital tract didelphic-amphidelphic vs. monodelphic-prodelphic in Batwanema gen. n. The procorpus is sub-cylindrical in Chokwenema gen. n. in opposition to the clavate procorpus of Batwanema gen. n. Moreover, Chokwenema gen. n. posses a single, evident truncate first cephalic annule, slightly inflated instead of the two hardly marked annuli of Batwanema gen. n., barely expanded.

Lepidonema and Salesia also bear scale-like projections in the cervical cuticle and shows a didelphic-amphidelphic genital system ( Travassos and Kloss 1958). In addition, Lepidonema have a sub-cylindrical procorpus. Chokwenema gen. n. can be differentiated from both by the arrangement of the cervical spines with eight scales in the first row and the characteristic bifurcation of these, their number increasing towards the end of the spiny region. Lepidonema and Salesia present more elements in their first rows of spines, that are not bifurcated. Moreover, Salesia present a clavate procorpus vs. the sub-cylindrical of Chokwenema gen. n.

The other digonant genus with spines in the cuticle and sub-cylindrical procorpus is Soaresnema Travassos & Kloss, 1958, which can be segregated from Chokwenema gen. n. by lacking scales in the cervical cuticle, by the spines forming transverse rows vs. opposite rows and by the larger number of elements in the first row (16) vs. eight in Chokwenema gen. n.

Type host.

Didimoides cf. parastictus (Imhoff, 1843) ( Coleoptera : Passalidae ).

Other host.

Pentalobus barbatus (Fabricius, 1801) ( Coleoptera : Passalidae ).

Site.

gut caeca.

Type locality.

Mongwalu, Ituri province, Democratic Republic of Congo.

Etymology.

Specific epithet derived from the Greek lepidos: scale and phoreus: to bear, after the scale-like projections of the cervical cuticle.