Mylonchulus kermaniensis, Shokoohi, Ebrahim, Mehrabi-Nasab, Abdolrahman, Mirzaei, Mahdieh & Peneva, Vlada, 2013

Shokoohi, Ebrahim, Mehrabi-Nasab, Abdolrahman, Mirzaei, Mahdieh & Peneva, Vlada, 2013, Study of mononchids from Iran, with description of Mylonchulus kermaniensis sp. n. (Nematoda: Mononchida), Zootaxa 3599 (6), pp. 519-534 : 524-528

Mylonchulus kermaniensis sp.n.

( Figs. 3 & 4 )

Material examined. Six females, in good preservation.

Measurements. See Table 2.

Description

Female: Body almost cylindrical, ventrally curved after fixation. Cuticle smooth under LM, 3 µm wide at mid body. Head region continuous with neck, having six lips bearing 6 + 4 papillae. Amphid openings oval, aperture 4–5 µm wide, located 9–12 µm from anterior end. Buccal cavity large, goblet -shaped, about 1.5–1.6 times as long as wide, with thick, cuticularised vertical walls, 2 µm diameter. Dorsal wall bearing a sharp, 8–10 µm long and 4–5 µm wide dorsal tooth, directed forward, located in the anterior half of buccal cavity at 56–60% from its base; two foramina present at the base of buccal cavity lying close to each other, 4–6 µm long. Six transverse rows of rasplike denticles on subventral walls posterior to the dorsal tooth, the sixth row consisting of four denticles. Nerve ring at 40–47% of neck length. Excretory pore opening not visible. Cardia conoid, surrounded by intestinal tissue. Reproductive system amphidelphic. Ovaries more or less straight, reflexed and with one row of oocytes. Oviduct long, 99–108 µm long, 1.6–1.9 times corresponding body diameter. Uterus 74–89 µm long, 2.1–2.3 corresponding body diameter. Vagina with parallel walls, less than half of corresponding body diameter, pars refringens vaginae with two drop-like sclerotised pieces. Vulva a transverse slit with, protruding, located posterior to mid part of body. One prevulval papilla, located 11 µm anterior to vulva and one postvulval papilla, located 26–30 µm posterior to vulva present, observed in two specimens. Eggs 1.6–2.4 times the corresponding body diameter. Rectum 0.7–0.9 times the anal body diameter. Tail slightly sigmoid, sharply bent ventrad with digitate posterior portion slightly but clearly bent dorsad. Caudal pores not observed. Caudal glands grouped, spinneret bearing terminal opening.

Male. Not found.

Diagnosis. Mylonchulus kermaniensis sp. nov. is characterized by its body 1.3–1.5 mm long, head region continuous, buccal capsule of medium size (24– 27 x 15–18 µm), six rows of rasp-like denticles, the sixth line of rasp-like denticles consisting of four denticles, amphidelphic reproductive system, female tail 37–49 μm long (c=27.9–38.9, c'=1.2–1.7), slightly sigmoid, sharply bent ventrad with digitate posterior portion slightly but clearly bent dorsad, terminal opening of spinneret.

M. cf. hawaiiensis M. kermaniensis sp. n. M. truncatus Locality Jiroft Kerman Dalfard

Kerman

Province Kerman Kerman

Soil

Habitat Palm date 6Ƥ Soil sediment N 10Ƥ 2Ƥ Character - Holotype Paratype - Tail length as % of total body length 4.4±0.6 (3–5) 2.9 3.1±0.4 (2.6–3.6) 12.4–11.8

Relationship. According to key of the genus Mylonchulus provided by Andrássy (1992) and modified by Ahmad and Jairajpuri (2010), the species M. sigmaturus Cobb, 1917 , M. sigmaturellus Mulvey, 1961 , M. agilis Doucet, 1980 , M. paitensis Yeates, 1992 , M. dentatus Jairajpuri, 1970 and M. sessus Jairajpuri, 1982 (considered as a synonym of M. sygmaturus by Andrássy, 1993) form a group characterized by a sigmoid tail, strongly bend ventrad with a digitate posterior portion slightly inclining dorsad and terminal opening of spinneret. Mylonchulus kermaniensis sp. n. is the most similar to M. paitensis described from New Caledonia but can be differentiated from it by different number of rasp-like denticles (6 vs 5 rows), narrower (22–25 vs 25–29 µm) and differently shaped (continuous vs wider than adjacent body) lip region, shorter buccal capsule (24–27 vs 28–29 µm), elevated vulval region (vs not elevated), presence of advulval papillae vs absent and differently shaped tail (digitate portion dorsaly bent vs straight). Tabassum et al., (2001) and Farahmand et al., (2009a) reported as M. paitensis some specimens from Pakistan and Iran, which are morphologically similar to the studied material, however, they are different in tail morphology, absence of vulval papillae and grouped caudal glands (vs in tandem). Further, the new species can be differentiated from the closely related M. sigmaturus by its differently shaped lip region (continuous vs set off), rasp-like denticles (six vs 7–8 rows), sixth line of rasp-like denticles (bearing four denticles vs bearing more four denticles), submedian teeth (small vs large), digitate portion of tail without caudal pores vs digitate portion of tail bearing caudal pores, higher c’ values (c’=1.3–1.7 vs 0.8–1.0) and presence of advulval papillae vs absent; from M. sigmaturellus by its shorter body (1.3–1.5 vs 1.6–2.6 mm) and tail (37–49 vs 55–80 µm), lower c’ values (c’=1.3–1.7 vs c’=2–2.5) and differently shaped lip region (continuous vs offset); from M. agilis the new species differs in shorter body (L=1.3–1.5 vs 1.6–2.00 mm), number of rows of rasp-like denticles (6 vs 6–9 rows, sixth rows bearing four vs sixth rows bearing more denticles), narrower lip region (21.5–25 vs 30 µm), lower c values (c=27.9–38.9 vs 37.9–67.6), buccal cavity shape (broad vs funnel shape) and length (24–27 vs 28–30 µm), vulval papillae (present vs absent) and males absent vs males present. In comparison with the M. dentatus the new species differs in number of rows of rasp-like denticles (6 vs 10–15), submedian teeth (small vs large). Finaly, the new species differs from M. sessus in the number of rows of rasp-like denticles (6 vs 7–8), anterior rows of denticles not prominent (vs prominent), larger submedian teeth (vs smaller), shorter rectum (19–25 vs 29–30 µm) and longer tail (37–49 vs 25–33 µm, c=27.9–38.9 vs c=47–55; c’=1.3–1.7 vs 0.9).

Type habitat and locality. The specimens were recovered from soil, Kerman (Kerman province), southeastern Iran (N: 30°16ʹ48.97ʺ; E: 57°04ʹ0 1.27ʺ)

Type material. Female holotype and four female paratypes deposited in the nematode collection of Plant Protection Department, College of Agriculture, Shahid Bahonar University of Kerman, Iran. One paratype female deposited in the Laboratory of Nematology of University of Jaen ( Spain).

Etymology. The specific epithet refers to the locality where the species has been recovered.

Figures

FIGURE 3. Mylonchulus kermaniensis sp. n. A, B, C: Buccal cavity. D: Entire female. E: Cardia diagram. F: Female reproductive system. G: Vagina with vulval papillae. H – J: Female tail.

FIGURE 4. Mylonchulus kermaniensis sp. n. (LM). A: Neck. B, C: Buccal cavity. D: Eggs. E: Amphids (arrow). F: Vaginal region. G: Female posterior end.