Nais elinguis Müller, 1773

Cui, Yongde, He, Xuebao, Peng, Yu & Wang, Hongzhu, 2015, Records of Naididae and Lumbriculidae (Clitellata) from Tibet, China, with description of a new species of Nais, Zootaxa 3956 (4), pp. 513-530 : 519-520

8. Nais elinguis Müller, 1773

( Figure 3 )

Nais elinguis Müller. Liang 1964: 644 –645. Nais barbata Müller. Liang 1962: 16 –17.

Material. Lhasa River: ST8, 5 spms (2 balsam mounts); ST9, 2 spms; ST11, 4 spms; ST17, 11 spms; ST61, 1 spm; ST62, 12 spms.

Description of new material. Length 2.6–3.2 mm, 13–18 segments. Eyes present. Stomachal dilatation gradual in VII–VIII. Ventral chaetae of II–V 4–5 per bundle, 90–98 Μm long, with nodulus slightly distal or median, from III on 2–5 per bundle, 82–88 Μm long, with nodulus distal. Distal tooth of all ventral chaetae 2–3 times as long as proximal. Dorsal chaetae beginning in VI, hairs 1–3 per bundle, 275–350 Μm long, needles ( Fig. 3 A) with two teeth about 4 Μm long, distal tooth slightly longer than proximal tooth. Penial chaetae ( Fig. 3 B; Fig. 3 C, ps) 5 per bundle, 102–110 Μm long, 4 Μm width, with a simple distal hook. Vas deferens ( Fig. 3 C, vd) short, wholly surrounded by abundant prostate gland ( Fig. 3 C, pr) cells, joining atria subapically. Atrial ampulla ( Fig.

3C, at) ovoid, with a thick wall. Spermathecae ( Fig. 3 C, sa) paired in V, pear-shaped, duct short, spermatozeugmata absent.

Remarks. Cosmopolitan. The characters of the new material agree with previous descriptions ( Sperber 1948; Timm 1999). Specimens are redescribed here because this is the first record of sexually mature individuals of this species from China. First record from Tibet.

Figures

FIGURE 3. Nais elinguis Müller, 1774. A. Needle chaeta. B. Penial chaeta. C. Ventral view of sexual organs in segments V – VI. Scale bars: A – B 20 µm, C 40 µm.