Bryodrilus diverticulatus Cernosvitov 1929

Bryodrilus diverticulatus Černosvitov, 1929

(Figure 11)

Material examined. 17 specimens (two were deposited in the National Institute of Biological Resources, Korea; NIBRIV0000837802, slide No. 2578, NIBRIV0000837803, slide No. 2611).

This species is widespread in the northern hemisphere (Christensen & Dózsa-Farkas 2006). The Korean specimens agree with the descriptions of the species (Černosvitov 1929, Christensen & Dózsa-Farkas 1999, 2006), but are slightly smaller, 6–8 mm long, (vs. 7–12 mm in literature) 340–450 μm wide at XII in vivo, segments 30–38. Chaetae sigmoid, 2–6 per bundle (Fig. 11B). Brain straight or slightly concave posteriorly (Fig. 11A). Clitellum girdle-shaped, gland cells arranged irregularly. Two pairs of oesophageal appendages, hollow, lobed, pulsating in VI (Figs 11D, H, I). Dorsal vessel arising in clitellar region, blood colourless. 7 pairs of preclitellar nephridia (4/5–10/11). Intestine widens abruptly from VII to IX (especially in VIII–IX) then narrows in X–XII (Fig. 11C), as has been described by Černosvitov (1929). Coelomocytes discoid, transparent. Sperm funnel 60–100 μm long, 1.5–3 times longer than wide (Figs 11 E–G). Male glandular bulb variable. Spermathecae with elongate ectal ducts, ampullae slightly wider than ducts, without diverticula, with joint proximal attachment to oesophagus dorsally (Figs 11H, I). Some glands at the ectal orifices.

Distribution and habitat in Korea. Mt. Deogyu, Seolcheon-myon, Muju-gun, Jeollabuk-do, soil and litter layers of Sasa borealis forest, N 35°52’17.5”, E 127°46’33.9”, 761 m asl; Mt. Gyebangsan, Nodong-ri, Yongpyeong-myeon, Pyeongchang-gun, Gangwon-do, Q. mongolica forest, N 37°42’27.92”, E 128°29’02.34”, 848 m asl; Mt. Gyebangsan, Nodong-ri, Yongpyeong-myeon, Pyeongchang-gun, Gangwon-do, soil and litter layers of Q. mongolica forest, N 37°42’24.78”, E 128°29’09.95”, 804 m asl; Mt. Odaesan, Sangwonsa, Dongsan-ri, Jinbu-myeon, Pyeongchang-gun, Gangwon-do, soil and litter layers, mixed forest, N 37°47’03.63”, E 128°33’44.06”, 906 m asl; Mt. Odaesan, Waljeongsa, Dongsan-ri, Jinbu-myeon, Pyeongchang-gun, Gangwon-do, Korea, soil and litter layers, Abies holophylla forest, N 37°43’36.93”, E 128°35’47.48”, 630 m asl; Mt. Chiaksan, Hakgok-ri, Socho-myeon, Wonju-si, Gangwon-do, soil and litter layers of mixed forests, N 37°22’58.07”, E 128°03’30.83”, 484 m asl.