Metaphire donganensis Jin & Jiang, 2024

Jin, Qing, Li, Jiali, Jiang, Jibao & Qiu, Jiangping, 2024, Four new earthworm species of the genera Amynthas and Metaphire (Oligochaeta, Megascolecidae) from Hunan and Anhui provinces, China, ZooKeys 1210, pp. 247-271 : 247-271

Metaphire donganensis Jin & Jiang sp. nov.

Fig. 5

Material examined.

Holotype. • 1 clitellate ( HU 201613-01 A ), China, Hunan Province, Dongan City (26.35499 ° N, 111.19531 ° E), 172 m elevation, brown soil under vegetable field in farmland, 4 May 2016, JB Jiang, J Sun, Y Dong, and Y Zheng . Paratypes. 13 clitellates in total • 1 clitellate ( HU 201613-01 B ), China, Hunan Province, Dongan City (26.35499 ° N, 111.19531 ° E), 172 m elevation, brown soil under vegetable field in farmland, 4 May 2016, JB Jiang, J Sun, Y Dong and Y Zheng • 2 clitellates ( P 1 CJHUSH 190511779 N 9-03 ), China, Hunan Province, Liuyang City (28.32795 ° N, 113.52008 ° E), 112 m elevation, red soil under vegetable in vegetable garden, 11 May 2019, Y Dong, YF Qin and YZ Wu • 7 clitellates ( P 1 CJHUSH 190512778 N 11-01 ), China, Hunan Province, Yueyang City (28.91995 ° N, 113.70132 ° E), 179 m elevation, brown soil under rape in rape field, 12 May 2019, Y Dong, YF Qin and YZ Wu • 1 clitellate ( P 1 CJHUSH 190512096 Q 3-04 ), China, Hunan Province, Linxiang City (29.33550 ° N, 113.40176 ° E), 51 m elevation, brown sandy soil under shrub in grove, 12 May 2019, Y Dong, YF Qin and YZ Wu • 2 clitellates ( P 1 CJHUSH 190518092 Q 6-01 ), China, Hunan Province, Yuanjiang City (29.04369 ° N, 112.29798 ° E), 48 m elevation, brown soil under litter next to the house, 18 May 2019, Y Dong, YF Qin and YK Li .

Diagnosis.

Size medium to large. Spermathecal pores in 6 / 7–8 / 9, separated by 1 / 3 of body circumference. Male pores in XVIII, separated by 1 / 3 of body circumference, each on the bottom center of the longitudinal copulatory chamber. Sometimes the copulatory chamber eversion is ridged. Spermathecae three pairs in VII – IX, ampulla heart- or rod-shaped, duct thick and as long as ampulla. Diverticulum as long as main pouch (duct and ampulla together), slender and straight at proximal part, terminal 1 / 2 dilated into twisted in zigzag fashion. Intestinal caeca are simple. Prostate glands are well developed.

External characters.

Pale brown dorsal and ventral pigmentation. Dimensions 72–159 mm by 4.6–7.0 mm at clitellum, segments 78–111. Annulus present on IX – XVIII. The dorsal midline is clearly visible and purplish brown. First dorsal pore of all examined individuals in 12 / 13. Prostomium 1 / 2 epilobous. Clitellum annular, pale taupe, in XIV – XVI, smooth, setae invisible externally. Setae numbering 20–34 at III, 20–46 at V, 28–58 at VIII, 52–66 at XX, 58–70 at XXV; 8–13 between male pores; 14–17 ( VI), 16–20 ( VII) and 17–21 ( VIII) between spermathecal pores; setal formula, aa = 1.0–1.6 ab, zz = 1.2–1.8 zy. Male pores one pair in XVIII, separated by 1 / 3 body circumference, each on the bottom center of the longitudinal copulatory chamber, multiple radioactive folds on the outer edge (Fig. 5 A ). Sometimes the copulatory chamber eversion is ridged (specimen P 1 CJHUSH 190511779 N 9-03 , P 1 CJHUSH 190512096 Q 3-04 and P 1 CJHUSH 190518092 Q 6-01 ) (Fig. 5 D ). Female pore single in XIV, oval, milky white. Spermathecal pores three pairs in 6 / 7–8 / 9, ventral, large eye-like, milky white porophore in center, separated by 1 / 3 body circumference.

Internal characters.

Septa 5 / 6–7 / 8 thick and muscular, 10 / 11–12 / 13 slightly thickened, 8 / 9 and 9 / 10 absent. Gizzard spherical, in IX – X. Intestine enlarged distinctly from XV. Intestinal caeca paired in XXVII, extending anteriorly to XXIII, simple, smooth dorsal margin, weakly constricted on ventral margin (Fig. 5 C ). Four esophageal hearts in X – XIII, the latter three are more developed than the first pair. Male sexual system holandric, testis sacs two pairs, in X and XI, well developed, left and right lobes connected on the ventral side. Seminal vesicles two pairs, extending in XI and XII, well developed, left and right lobes separated on the ventral side. Prostate glands well developed, inserting in XVIII and extending to XVI and XXII, strip lobate, prostatic duct U-shaped, slightly thicker at the distal part (Fig. 5 B ). No accessory glands observed. Spermathecae three pairs in VII – IX, ampulla heart- or rod-shaped, ~ 3.2–8.0 mm long in holotype; ampulla duct is swollen and as long as ampulla. Diverticulum as long as main pouch (duct and ampulla together), slender and straight at proximal part, terminal 1 / 2 dilated into twisted in zigzag fashion. No accessory glands observed (Fig. 5 E ).

Etymology.

The species is named after its type locality.

Remarks.

Metaphire donganensis sp. nov. with three pairs spermathecal pores in 6 / 7–8 / 9, keys to the Metaphire houlleti group, which includes 44 species ( Sims and Easton 1972; Feng 1984; Feng and Ma 1987; Qiu and Zhong 1993; Sun et al. 2018). Metaphire vulgaris agricola (Chen, 1930) is slightly akin to the new species in the respects of body size, first dorsal pore in 12 / 13, clitellum in XIV – XVI, setae number, the position and characteristics of spermathecal pores, simple intestinal caeca, and the characteristics of diverticulum. Instead, the difference between the two species is in the pigmentation, pale brown in M. donganensis sp. nov., earthy yellow in M. vulgaris agricola ( Feng, 1981) . Further, the ventral distance of spermathecal pore and male pores are 1 / 3 C and 1 / 3 C in M. donganensis sp. nov., but 1 / 4 C and 1 / 4 C in M. vulgaris agricola ; no papillae within spermathecal pore region of M. donganensis sp. nov., but paired papillae in VII of M. vulgaris agricola ; no papillae within male pore region of M. donganensis sp. nov., while paired papillae on the inner side of male pore in M. vulgaris agricola ; prostate glands well developed in XVI – XXII of M. donganensis sp. nov., nevertheless in XVII – XX with accessory glands invisible in M. vulgaris agricola ; spermathecae ~ 3.2–8.0 mm long, ampulla heart- or rod-shaped, duct swollen, as long as ampulla of M. donganensis sp. nov., while spermathecae ~ 4.5 mm long, ampulla pear-shaped, ampulla duct 1 / 2 of ampulla in M. vulgaris agricola ; no accessory glands in M. donganensis sp. nov., while paired accessory glands in the VIII of M. vulgaris agricola (Table 4 ).

We compare the new species to Metaphire tschiliensis lanzhouensis ( Feng, 1984) , which has three pairs of spermathecal pores in 6 / 7–8 / 9. They share several common characters in the first dorsal pore position, clitellum in XIV – XVI, setae number, the position of spermathecal pores, the position and characteristics of male pores, no papillae within spermathecal pore region, simple intestinal caeca, and the characteristics of the diverticulum. Quite the contrary, the new species is smaller than M. tschiliensis lanzhouensis . Beyond that, coloration is pale brown in M. donganensis sp. nov., earthy yellow in M. tschiliensis lanzhouensis ; spermathecal pores are obvious in M. donganensis sp. nov., but inconspicuous in M. tschiliensis lanzhouensis ; no papillae within male pore region of M. donganensis sp. nov., but one in pouch of M. tschiliensis lanzhouensis ; prostate glands well developed in XVI – XXII of M. donganensis sp. nov., while underdeveloped in XVII – XIX with a large lumpy accessory gland in M. tschiliensis lanzhouensis ; spermathecae ~ 3.2–8.0 mm long, ampulla heart- or rod-shaped of M. donganensis sp. nov., but spermathecae ~ 4 mm long, ampulla spherical-shaped in M. tschiliensis lanzhouensis (Table 4 ).

Considering the three pairs of spermathecal pores in 6 / 7–8 / 9, we compared the new species with Metaphire viridis Feng & Ma, 1987 . Both have first dorsal pores in 12 / 13, clitellum in XIV – XVI, the same position and characteristics of spermathecal pores, simple intestinal caeca, and the same characteristics of diverticulum. However, the new species differs from M. viridis in many respects. Metaphire donganensis sp. nov. is smaller than M. viridis with pale brown coloration; setae number of M. donganensis sp. nov. is less than M. viridis ; the ventral distance of spermathecal pore and male pores are 1 / 3 C and 1 / 3 C in M. donganensis sp. nov., but 1 / 2 C and 1 / 2 C in M. viridis ; no papillae within spermathecal pore region of M. donganensis sp. nov., while paired in VII, VIII, and IX of M. viridis ; no papillae within male pore region of M. donganensis sp. nov., but four in pouches in M. viridis ; prostate glands in XVI – XXII of M. donganensis sp. nov., while XV – XX or XVII – XIX with a lumpy accessory gland in M. viridis ; no accessory glands in M. donganensis sp. nov., whereas paired in the VII, VIII and IX of M. viridis ; spermathecae ~ 3.2–8.0 mm long, ampulla heart- or rod-shaped of M. donganensis sp. nov., nevertheless spermathecae ~ 4 mm long, ampulla spherical- or oval-shaped in M. viridis ; no accessory glands of M. donganensis sp. nov., while paired in VII, VIII, and IX of M. viridis (Table 4 ).

We also compare the new species with Metaphire ptychosiphona Qiu & Zhong, 1993 on the basis of the position and characteristics of male pores, no papillae within spermathecal pore and male pore regions, simple intestinal caeca, and the same characteristics of the diverticulum. Nevertheless, the new species is smaller than M. ptychosiphona . In addition, pale brown in M. donganensis sp. nov., but grey brown in M. ptychosiphona ; first dorsal pore in 12 / 13 of M. donganensis sp. nov., while in 11 / 12 of M. ptychosiphona ; setae number of M. donganensis sp. nov. less than M. ptychosiphona ; the ventral distance of spermathecal pore is 1 / 3 C in M. donganensis sp. nov., but 2 / 5 C in M. ptychosiphona ; spermathecal pores obvious in M. donganensis sp. nov., but inconspicuous in M. ptychosiphona ; prostate glands in XVI – XXII of M. donganensis sp. nov., while XVI – XVIII or XVII – XIX in M. ptychosiphona ; and spermathecae ~ 3.2–8.0 mm long, ampulla heart- or rod-shaped, duct swollen, as long as ampulla in M. donganensis sp. nov., nevertheless spermathecae shorter, ampulla rod-shaped, duct shorter than ampulla in M. ptychosiphona (Table 4 ).

The new species is also close to Metaphire sanmingensis Sun & Jiang, 2018 in body size, clitellum in XIV – XVI, the position of spermathecal pores and male pores, simple intestinal caeca, prostate glands, and the characteristics of the ampulla and diverticulum. However, the new species is easily distinguished from M. sanmingensis in pigmentation, first dorsal pore position, setae number, papillae within spermathecal pore region, and the characteristics of male pores and papillae within male pore region (Table 4 ).

Figures

Figure 5. M. donganensis sp. nov. A ventral view showing spermathecal pores, and male pores B prostate glands C intestinal caeca D male pores of paratype (P 1 CJHUSH 190511779 N 9-03) E spermathecae. Abbreviations: sp, spermathecal pores; mp, male pores.