Metaphire reclusa Yuan & Dong, 2019

Yuan, Zhu, Dong, Yan, Jiang, Jibao, Zhao, Qi & Qiu, Jiangping, 2019, Three new species of earthworms (Oligochaeta: Megascolecidae) from Yunnan Province, China, Zootaxa 4664 (3), pp. 390-400 : 397

Metaphire reclusa Yuan & Dong sp. nov.

( Figure 3 )

Type material. Holotype. Clitellate specimen ( YN 201109 -03 A): China, Yunnan, Xishuangbanna , Mengla County (21.40389° N, 101.62417° E), 722 m asl, red soil in forest, 20 July 2011, J.B. Jiang, J. Sun, X.D. Lei and H.W. Feng . Paratypes. one clitellate specimen ( YN 201109 -03 B) and one clitellate specimen ( YN 201109 -06 ) with the same data as for holotype; two clitellate specimens ( YN201739-07 ): China, Yunnan, Ruili, Tongbiguan Nature Reserve (24.07276° N, 97.81889° E), 1159 m asl, 11 August 2017, J.B. Jiang, Y. Dong, Q. Zhao, Z. Yuan .

NCBI accession numbers of some of the type specimens are listed in Table 2 .

Etymology. The species is named after its characteristic absence of male pores.

Diagnosis. Dimensions 110–149 mm by 4.2–4.6; segments 113–132. Setae numbering 28–36 at III, 32–38 at V, 46–62 at VIII, 61–74 at XX, 64–75 at XXV; 8–10 between male pores. No spermathecal pores. Male pores in copulatory chambers in XVIII, openings of copulatory chambers about 1/3 body circumference ventrally apart, each adjacent to a transverse tubercle and surrounded by two rhombus folds. Prostate glands located in XVII–XVIII, undeveloped. Prostate gland on the right side bigger than on the left side in all specimens, ducts U-shaped. A round accessory gland on the root of each prostate gland.

External characters. Tawny dorsal pigment, no pigment on ventrum. Dimensions 110–149 mm by 4.2–4.6; segments 113–132. First dorsal pore in 11/12. Prostomium 1/2 epilobous. Clitellum in 9/10XIII–1/10XVII, brown on dorsum, no pigment on ventrum, setae absent, dorsal pores absent. Setae numbering 28–36 at III, 32–38 at V, 46–62 at VIII, 61–74 at XX, 64–75 at XXV; 8–10 between male pores. Setal formula: AA = 1.9–2.0 AB, ZZ = 1.8–2.0 ZY. Five specimens dissected, no spermathecal pores. Female pore single in XIV. Male pores in copulatory chambers in XVIII, openings of copulatory pouches about 1/3 body circumference ventrally apart, each adjacent to a transverse tubercle and surrounded by two rhombus folds.

Internal characters. Septa 5/6–6/7 thick and muscular, 7/8 and 10/11–14/15 slightly thickened, 8/9–9/10 absent. Gizzard bucket-shaped, in VIII–X. Intestine enlarged distinctly from XV. The intestinal caeca started from XXVII and ended in XXIII, simple, smooth, finger-shaped. Hearts four pair in X–XIII, the first pair relatively small, the others larger. Testis sacs two pairs in X–XI, ovoid, developed, joined with each other. Seminal vesicles two pairs in XI and XII, the second pair extending in XIII, separated from each other. Prostate glands located in XVII–XVIII, undeveloped, gland on the right side bigger than the left in all specimens, ducts U-shaped. A round accessory gland on the root of each prostate gland. No spermathecae.

Remarks. Metaphire reclusa sp. nov. cannot be placed in any of Metaphire species-groups in Sims and Easton (1972), because those groups are mainly characterized and distinguished by the presence of spermathecae in different numbers and positions.

M. reclusa is closely related to M. anomala (Michaelsen, 1907) . According to Gates (1925, 1972), many specimens of M. anomala show large variability of sexual organs due to parthenogenetic degeneration, including absense of male pores (see above, A. demptus , remarks) and absence of spermathecae. M. reclusa may therefore be confused with athecate morphs of M. anomala , a species of similar body size. Differences of M. anomala to M. reclusa (other than the spermathecae and male pores structures) are as follows ( Table 4 ): 1st dorsal pore in 12/13 (11/ 12 in M. reclusa ), clitellum in XIV–XVI, (9/10XIII–1/10XVII in M. reclusa ). Also, setal numbers before clitellum of M. anomala are much higher and setae are more closely spaced than in M. reclusa . Based on setal formula, ZZ is often slightly smaller than ZY in M. anomala ; AA = 1.9–2.0 AB, ZZ = 1.8–2.0 ZY in M. reclusa .

Figures

FIGURE 3. Metaphire reclusa Yuan & Dong, sp. nov. A. Male pore region. B. Intestinal caecum. C. Left prostate gland (pg) and accessory gland (ag). D. Right prostate gland and accessory gland.