Discotylenchus brevicaudatus Brzeski, 1985

Ghaemi, Razieh, Pourjam, Ebrahim, Atighi, Mohammad Reza, Pedram, Majid & Karssen, Gerrit, 2012, First record of the genus Discotylenchus Siddiqi, 1980 (Nematoda: Tylenchidae) from Iran, with description of one new and data on two known species, Zootaxa 3493, pp. 72-82 : 76-77

Discotylenchus brevicaudatus Brzeski, 1985

( Figs. 3 , 5 )

Measurements. See Table 2.

This population was recovered from the rhizosphere of plum ( Prunus domestica L.) trees in a garden, close to city of Bojnourd, Northern Khorasan province, north-eastern Iran during May 2009. Morphological and morphometric characters of the Iranian population of D. brevicaudatus agree completely with those in original description (see Table 2), although there is a wider range for some morphometric data compared to the type population i.e. the Iranian population has a longer body (0.42–0.46 vs 0.32–0.39 mm), slightly shorter stylet (6–7 vs 7–8 µm), longer pharynx (116–132 vs 69–73 μm), longer tail (57–77 vs 35–47 μm), smaller c (5.9–7.8 vs 8.1–9.8), higher c' (6.3–9.6 vs 4.5–6.0) and slightly smaller V (68.2–71.6 vs 71–73). From a morphological perspective, the basal bulb in Iranian population is long and bottle shaped in dimension of 40–55×7.5–8.5 µm, whereas in the original population it is pyriform.

The male of this species is described for the first time and is similar to females in general morphology except for character states associated with sexual differences. Testis is single, anteriorly outstretched and 91±6 (85–99) μm long. Spicules slender, ventrally curved. Gubernaculum simple, bursa smooth, adcloacal and 17±2 (15–19) µm long.

Remark. As in the original description ( Brzeski, 1985), the females of the Iranian population had sperm in genital tract and the males were also recovered, demonstrating the amphimictic nature of reproduction in this species.

TABLE 2. Morphometrics of Discotylenchus brevicaudatus . All measurements are in μm, and in the form: mean ± s.d. (range). Iranian population Brzeski, 1985

Figures

FIGURE 3. Discotylenchus brevicaudatus. A, B: Female and male entire body; C: Anterior end in detail; D: Pharyngeal region; E: Male posterior end; F: Female tail.

FIGURE 5. Discotylenchus brevicaudatus (A – E) and Discotylenchus discretus (F – I). A: Anterior end; B: Female tail; C: Male posterior end; D: Bursa; E: Neck region showing bottle shaped terminal bulb; F: Anterior end; G: Vagina and spermatheca; H: Male posterior end; I: Female tail (all scale bars = 10 µm).