Mononchus truncatus Bastian, 1865

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 : 528-532

Mononchus truncatus Bastian, 1865

( Fig. 1 , F–I)

Material examined. Two females, in good preservation

Measurements. See Table 2.

Description

Female: Body almost cylindrical, J shape after fixation. Cuticle smooth under LM, 3 µm wide at mid body. Small transverse striae visible under SEM. Head region continuous with neck, having six lips bearing 6 + 4 papillae. Amphid openings oval, located anterior to the dorsal tooth, its aperture 4–6 µm wide, located 15–17 µm from anterior end. Buccal cavity elongate oblong, barrel-shaped, about 2.7 times as long as wide, with thick, cuticularised vertical walls, 1.6 µm thick. Dorsal wall bearing a sharp, slightly pointed, 6.4 µm long and 3.1 µm wide dorsal tooth, directed forward, located in the anterior half of buccal cavity at 60% from its base; two foramina present at the base of buccal cavity lying close to each other, 6–8 µm long. Nerve ring located at middle of pharynx, at 33–35% of neck length. Excretory pore opening located at 41–48% of neck length. Cardia conoid, surrounded by intestinal tissue. Reproductive system amphidelphic. Ovary more or less straight, with flexure to the vulva and only one row of oocyte. Vagina extending inward for less than half of the body width; with parallel walls, pars refringens vaginae with two ovoid sclerotisations. Vulva a transverse slit, slightly protruding, located posterior to mid part of body. Advulval papillae absent. Rectum 1.1–1.2 times the anal body diameter. Tail uniformly ventrally curved, tapering to cylindrical shape in posterior part with 6.9–7.1 µm diameters, bearing a minute hair on ventral part, Caudal glands in a group, spinneret opening terminal.

Male. Not found.

Locality. The material studied was recovered from soil sediments collected in Dalfard (Kerman province, Iran), south-eastern Iran (N: 29º 00’ 34.5”; E: 057º 35’ 33.8”).

Remarks. The morphometrics of the examined specimens conform well to the measurements of type / neotype specimens ( Andrássy, 2011). In comparison with those studied by Farahmand et al., (2009a) our specimens have a shorter body (1.5–1.7 vs 2–2.4 mm).

Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 Mylonchulus sigmaturus AY284756

2 Mylonchulus sigmaturus AY284757 0.01

3 Mylonchulus sigmaturus AY284755 0.03 0.03

4 Mylonchulus rotundicaudatus AY284751 0.0 1 0.0 1 0.0 2

5 Mylonchulus sigmaturus AB361446 0.0 3 0.0 3 0.0 1 0.0 3

6 Mylonchulus oceanicus AB361444 0.01 0.01 0.02 0.01 0.03

7 Mylonchulus brachyuris AB361436 0.01 0.00 0.02 0.01 0.03 0.00

8 Mylonchulus arenicolus AF036596 0.03 0.03 0.00 0.02 0.00 0.02 0.02

9 Mylonchulus hawaiiensis AB361441 0.01 0.01 0.02 0.01 0.03 0.01 0.01 0.02

10 Mylonchulus hawaiiensis AB361439 0.01 0.01 0.02 0.01 0.02 0.00 0.01 0.02 0.00

11 Mylonchulus hawaiiensis AB361440 0.01 0.01 0.02 0.01 0.02 0.00 0.01 0.02 0.00 0.00

12 Mylonchulus hawaiiensis AB361442 0.01 0.01 0.02 0.01 0.02 0.00 0.01 0.02 0.00 0.00 0.00

13 Mylonchulus hawaiiensis AB361438 0.01 0.01 0.02 0.01 0.02 0.00 0.01 0.02 0.00 0.00 0.00 0.00

14 Mylonchulus mulveyi AB361449 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.05 0.05 0.05 0.05 0.05 0.05

15 Mylonchulus oceanicus AB361443 0.01 0.01 0.02 0.01 0.03 0.00 0.00 0.02 0.01 0.00 0.00 0.00 0.00 0.05

16 Mylonchulus mulveyi AB361448 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.05 0.05 0.05 0.05 0.05 0.05 0.00 0.05

17 Mylonchulus brachyuris AY284754 0.01 0.01 0.02 0.01 0.03 0.00 0.00 0.02 0.01 0.00 0.00 0.00 0.00 0.05 0.00 0.05

18 Mylonchulus brachyuris AB361437 0.01 0.01 0.02 0.01 0.03 0.00 0.00 0.02 0.01 0.00 0.00 0.00 0.00 0.05 0.00 0.05 0.00

19 Mylonchulus cf. hawaiiensis JQ742964 0.02 0.01 0.02 0.01 0.03 0.01 0.01 0.02 0.01 0.01 0.01 0.01 0.01 0.05 0.01 0.05 0.01 0.01

20 Mylonchulus brachyuris AY284752 0.01 0.01 0.03 0.01 0.03 0.01 0.01 0.03 0.01 0.01 0.01 0.01 0.01 0.05 0.01 0.05 0.00 0.00 0.01 Family species Reference

Anantonchidae Anatonchus kafii Olia, Choudhary, Ahmad & Jairajpuri, 2004 Olia et al., 2004

A. tridentatus ( De Man, 1876) De Coninck, 1939 Loof et al., 1990 , Barooti, 1997

Miconchus studeri ( Steiner, 1914) Andrássy, 1958 Barooti & Nowruzi, 2000

Mononchidae Clarkus papillatus ( Bastian, 1865) Jairajpuri, 1970 Loof et al., 1990 ; Olia et al., 2004; Farahmand et al., 2009b

Coomansus parvus ( De Man, 1880) Jairajpuri and Khan, 1977 Loof et al., 1990 ; Farahmand et al., 2009b Mononchus aquaticus Coetzee, 1968 Farahmand et al., 2009a

M. pulcher Andrássy, 1993 Farahmand et al., 2009a

M. truncatus Bastian, 1865 Farahmand et al., 2009a ; Olia et al., 2004; Present paper

Prionchulus iranicus Farahmand, Eskandari, Viciguerra, Orselli & Karegar, 2009 Farahmand et al., 2009b P. muscorum ( Dujardin, 1845) Wu & Hoeppli, 1929 Loof et al., 1990

P. punctatus Cobb, 1917 Loof et al., 1990

Mylonchulidae Mylonchulus brachyuris ( Bütschli, 1873) Cobb, 1917 Loof et al., 1990 ; Farahmand et al., 2009a

M. cf. hawaiiensis ( Cassidy, 1931) Goodey, 1951 Present paper

M. kermaniensis sp. n. Present paper

M. minor (Cobb, 1893) Cobb, 1916 Loof et al., 1990 ; Nowruzi & Barooti, 1997

M. nainitalensis Jairajpuri, 1970 Olia et al., 2004

M. paitensis Yeates, 1992 Farahmand et al., 2009a

M. sigmaturellus ( Cobb, 1917) Mulvey, 1961 Loof et al., 1990 ; Nowruzi & Barooti, 1997

M. sigmaturus Cobb, 1917 Loof et al., 1990 ; Nowruzi & Barooti, 1997; Farahmand et al., 2009a DNA characterization of M. cf. hawaiiensis . The sequence lengths flanked by the two primers SSU-F-04 and SSU-R-26 of the 18S regions of M. cf. hawaiiensis isolate are ~900 base pairs (bps) long. The Blast test revealed that this population has only 5 base pairs difference from the Japanese populations ( AB361438 , AB361439 , AB361440 ; AB361442 ; 99% identity) of M. hawaiiensis . In comparison to other nearest population studied also from Japan showed 8 ( AB361441 ; 99% identity) base pairs differences.

Pairwise Maximum Composite Likelihood distance among 18S rDNA region of Mylonchulus species showed that M. hawaiiensis populations from Japan are not having much genetic variation. Within M. hawaiiensis population’s genetic variation is 0.01 ( Table 3). The genetic variation between M. cf. hawaiiensis ( JQ742964 ) and M. mulveyi was 0.05 and the highest within Mylonchulus species ( Table 3).

Figures

FIGURE 1. Mylonchulus cf. hawaiiensis (Cassidy, 1931) Goodey, 1951. (A-E) A: Neck. B: Buccal cavity. C: Female reproductive system. D: Entire female. E: Female posterior end; Mononchus truncatus Bastian, 1865. (F – I) F: Buccal cavity. G: Entire female. H: Female reproductive system. I: Female posterior end.