Globulidrilus helgei, Christensen & Dózsa-Farkas, 2012

Christensen, Bent & Dózsa-Farkas, Klára, 2012, A new genus Globulidrilus and three new enchytraeid species (Oligochaeta: Enchytraeidae) from Seoraksan National Park (Korea), Journal of Natural History 46 (45 - 46), pp. 2769-2785 : 2771-2777

publication ID

https://doi.org/ 10.1080/00222933.2012.737038

persistent identifier

https://treatment.plazi.org/id/03E16D7C-FFBE-FFD4-754F-F0788F8FFF2B

treatment provided by

Felipe

scientific name

Globulidrilus helgei
status

sp. nov.

Globulidrilus helgei View in CoL sp. nov.

( Figures 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4C View Figure 4 )

Type material

Holotype. G.1. slide No. 526, adult specimen, whole-mounted.

Type locality. Korea, Seoraksan National park. Abundant in a particularly moist spot rich in decaying organic matter. For further details see Material and methods.

Paratypes. P. 91. 1–10 slide No. 527, 531, 532, 533, 534, 535, 557, 566, 567, 568. All worms adult except on slide 535 (a subadult specimen, without eggs). All collection data are in holotype.

Etymology

Named in honour of the collector.

Description

Slender medium-sized reddish worm. Holotype 8.95 mm long, 340 µm wide at VIII and 390 µm at the clitellum (fixed), segments 36. Body length of paratypes 6–15 mm, width 240–350 µm at VIII and 300–440 µm at the clitellum (in vivo), length of fixed specimens 6.7–9.7 mm, width 250–310 µm at VIII, 290–410 µm at the clitellum, segments 31–37. Chaetae ( Figure 2A–B View Figure 2 ) sigmoid without nodulus, 2,3,(1)–2(1,0):2,3,4(1,0)–2(3), about 55–65 µm long and 5 µm wide, in posterior segments slightly longer, absent in XII. Head pore at 0/I inconspicuous; dorsal pores absent. Hyaline epidermal gland cells arranged in 2–3 transverse rows, rarely slightly pigmented in anterior segments.

Clitellum in XII–1/3XIII, hyalocytes and granulocytes in dense rows, granulocytes dominate dorsally (the size of hyalocytes and granulocytes about the same, 11–17 × 10–12 µm, fixed) ( Figure 2C View Figure 2 ), glands absent anteroventrally and between the penial bulbs but present posteroventrally ( Figure 2D View Figure 2 ). Body wall 18–25 µm thick, cuticle 2.0–2.5 µm (fixed). Brain ( Figure 1A View Figure 1 ) convex anteriorly and deeply incised posteriorly, about 170–200 µm long (fixed), 2–3 times longer than wide.

The two anterior pharyngeal glands in IV and V with well-developed ventral lobes but not united dorsally, the third pair in VI small, often with ventral lobes only, and sometimes even absent ( Figure 1C View Figure 1 ). Chloragocytes weakly developed. Dorsal blood vessel originates in XIV–XV, the anterior bifurcation in I, blood reddish ( Figure 2E View Figure 2 ).

Preclitellar nephridia from 6/7 to 9/10, four pairs, the two posterior often enlarged, anteseptale funnel and a few coils of the nephridial canal, postseptale much larger, the ectally leading canal arises near the septum but remains attached to the ventral side of the postseptale until sub-terminally ( Figures 1B View Figure 1 and 3A View Figure 3 ), the canal widens abruptly near the outer opening, diameter of these vesicles about 25 µm ( Figures 3B View Figure 3 and 4C View Figure 4 ). Coelomocytes ( Figure 2F View Figure 2 ) oval, wavy outline with fine hyaline plasma threads, 20–37 µm long (fixed) usually congregated in IV – V. Seminal vesicle absent. Sperm funnels ( Figures 1F View Figure 1 and 3C View Figure 3 ) 100–190 µm long and 30–40 µm wide, about 4–6 times as long as wide (fixed), collar of same width as the funnel itself, often bend backwards, sperm ducts very long and slender, about 3.5 µm wide (fixed), irregularly coiled in XII. Spermatozoa about 120–140 µm long, head 40–60 µm (in vivo) and 90 µm and 30 µm (fixed). Male copulatory organs ( Figures 2D View Figure 2 and 3D View Figure 3 ) small rounded compact penial bulbs, diameter 40–55 µm (fixed). No subneural glands, but approximately half the specimens have accessory sexual glands in XI or in XI and XIII: holotype (slide 526) in XI (87 × 50µm); paratype (slide 535) in XI (87 × 67µm) and in XIII (92 × 87µm), paratype (slide 534) two close glands in XI (85 × 55 and 85 × 45µm) and one in XIII (90 × 65µm) ( Figure 3D View Figure 3 ). Ectal duct of spermatheca devoid of glands along its length (140–200 µm), diameter near ectal opening 10–12 µm, gradually increasing entally (up to 22.5 µm). Ampulla thin-walled and onion-shaped, diameter 40–60 µm, sperm arranged in 1–4 regular bundles (diameter 20–27 µm) located near the outer opening and only occupying a smaller part of the lumen. Both ampullae attached to the oesophagus separately, by a narrow strand of tissue but without any open connection ( Figures 1D–E View Figure 1 and 3E–F View Figure 3 ). Simultaneously one to two mature eggs .

Distribution and habitat

Only known from the type locality.

Remarks

Marionina riparia Bretscher, 1899 View in CoL , a freshwater species with worldwide distribution, fits the aforementioned description of the new genus Globulidrilus View in CoL , and hence we suggest to include this species in the new genus, as Globulidrilus riparius ( Bretscher, 1899) View in CoL . The comparison of G. helgei View in CoL and G. riparius View in CoL , however, is not straightforward because of taxonomic problems in the latter. The poor original description of M. riparia View in CoL in Bretscher (1899) was first emended by Černosvitov (1937) and later by Nielsen and Christensen (1959), but these subsequent accounts, which were based on different material, increased the range of variation of taxonomic characters. In fact, if all descriptions and redescriptions of M. riparia View in CoL are considered, G. helgei View in CoL may be included in G. riparius View in CoL sensu lato, but we believe that such a broadly conceived taxon comprises several species, following Timm (2007). In Table 2 and in Figures 4A,B,D–F View Figure 4 we present the variant of G. riparius View in CoL that in our experience is the most common one in Europe, and here differences to G. helgei View in CoL are clear-cut and beyond doubt. Thus the genus Globulidrilus View in CoL comprises at least two species, but possibly more. For the time being, we retain the name G. riparius View in CoL for the variant outlined here. A taxonomic revision of G. riparius View in CoL sensu lato is urgently needed but beyond the scope of this article. Since type material is lacking, re-sampling of the type and reference localities will be necessary, and the problem should be addressed with morphological and molecular methods. Finally the name riparius View in CoL may have an older synonym with nomenclatural priority ( Timm 2007; Schmelz and Collado 2010).

as conceived here.

V

Royal British Columbia Museum - Herbarium

Kingdom

Animalia

Phylum

Annelida

Class

Clitellata

Order

Enchytraeida

Family

Enchytraeidae

Genus

Globulidrilus

Loc

Globulidrilus helgei

Christensen, Bent & Dózsa-Farkas, Klára 2012
2012
Loc

Globulidrilus

Christensen & Dózsa-Farkas 2012
2012
Loc

G. helgei

Christensen & Dózsa-Farkas 2012
2012
Loc

G. helgei

Christensen & Dózsa-Farkas 2012
2012
Loc

G. helgei

Christensen & Dózsa-Farkas 2012
2012
Loc

Globulidrilus

Christensen & Dózsa-Farkas 2012
2012
Loc

Globulidrilus helgei

Christensen & Dózsa-Farkas 2012
2012
Loc

Marionina riparia

Bretscher 1899
1899
Loc

M. riparia

Bretscher 1899
1899
Loc

M. riparia

Bretscher 1899
1899
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