Strigamia obliquidentata Jiang & Yu sp. nov.

Figs 1 J, 12

Material examined.

Holotype. China • ♂ (CMMI 20240924004 D), Jilin Province, Tonghua, Dongchang Dist., Yuhuangshan (41.7316°N, 125.9380°E), 830 m asl., 24. ix. 2024, leg. Chao Jiang.

Paratype. China • 1 ♂ (CMMI 20240926019 D), Jilin Province, Tonghua, Jindou Korean and Manchu Ethnic Town, Luojiagou (41.7407°N, 125.6516°E), 810 m asl., 26. ix. 2024, leg. Chao Jiang.

Diagnosis.

Body length reaching at least 40 mm; number of leg-bearing segments usually 55–57; with transverse suture on the cephalic plate; cephalic pleurite evidently without setae; with 35 pectinate hyaline teeth in the mandible; anterior margin of the second maxillae coxosternite deeply concave; telopodite distinctly longer than coxal projection of the first maxillae; denticle of tarsungulum extending obliquely downward, forming an approximately right angle with internal margin; internal and external margins of the tarsungulum subparallel along the basal part, gradually converging only along the distal part; calyx of poison gland ca. 2.8 times as long as wide, situated in the distal half of trochanteroprefemur; metasternites with sparse setae of various sizes; pore-fields not on the anterior part; metasternites with a mid-longitudinal deep sulcus; distinct sulcus separating pretergite and intercalary pleurites of the ultimate leg-bearing segment; metasternite of the ultimate leg-bearing segment smooth, with no concave on each side; coxal pores at least 15 on each coxopleuron; all sparse on the ventral surface of the coxopleuron, distinctly denser close to the lateral margin of the metasternite.

Description.

General features. Body 43 mm long; with 57–59 leg-bearing segments; narrowing forward and towards the posterior tip. Color (in ethanol 75 %) reddish yellow; forcipules darker.

Cephalic capsule (Fig. 12 A – C) sub-quadratic; ca. 1.1 times as wide as long; all margins convex; areolation uniform on the entire surface, less sclerotized along an indistinct transverse suture; setae arranged scattered. Clypeus with rather uniform areolation; sclerotized along the anterior margin and a median triangular area; fading close to the labrum and the paraclypeal sutures; 4 post-antennal setae aligned on the anterior part of the clypeus, grouped in the medial part, and 2 medial prelabral setae on the posterior part of the clypeus. Labrum slightly projecting backwards medially, without distinct mid-piece; marginal denticles absent, with two unordered rows of long slender hyaline filaments along the entire labral margin and further rows of shorter filaments behind.

Antennae (Fig. 12 B) almost uniform in width; ca. 3.3 times as long as the width of the head. Basal articles only slightly more elongated (article II ca. 0.9 times as long as wide); distal articles stouter (article XIII ca. 0.8 times as long as wide); article XIV ca. 2 times as long as wide. Setae gradually denser and shorter from the basal articles to the distal ones. Articles I – IX with three basal whorled long setae along with numerous short setae; remaining articles equipped solely with short setae.

Mandible (Fig. 12 D) with a single pectinate lamella with ca. 35 hyaline teeth.

First maxillae (Fig. 12 E). Coxosternite entire; uniformly areolate; without lappets; 3 + 3 setae on anterior middle part. Coxal projection sub-triangular; about as wide as long; ventral side with 6 + 5 small setae and 4 + 4 long setae on distal half; dorsal surface with numerous small sensilla on distal half. Telopodite longer than the coxal projection; distinctly articulated; without lappets; ventral side with 5 + 7 long setae and 3 + 3 short setae on distal half; dorsal surface with numerous small sensilla on distal half.

Second maxillae (Fig. 12 E). Coxosternite entire; uniformly areolate; anterior margin deeply concave; 5 + 3 small setae close to the anterior margin. Telopodite composed of three articles; gradually narrowing towards the tip; claws simple; almost straight and gradually tapering on the telopodite.

Forcipular segment (Fig. 12 F). Tergite sub-trapezoid; with lateral margins convex and subparallel; ca. 3.3 times as wide as long. Coxosternite ca. 1.8–2.2 times as wide as long on exposed part; anterior margin projecting with respect to its condyles; anterior border concave medially; coxopleural sutures strongly converging backward. Trochanteroprefemur ca. 1.1–1.5 times as wide as long; basal distance between trochanteroprefemora ca. 0.5 times of their basal breadth. Forcipular intermediate articles without denticles. Tarsungulum ca. 2.3–3.1 times as long as wide. Basal denticle of tarsungulum sub-triangular, extending obliquely downward, forming an approximately right angle with internal margin; ca. 0.3 times as long as the basal width of the tarsungulum. Internal and external margins of the tarsungulum subparallel along the basal part; gradually converging only along the distal part. Calyx of poison gland ca. 2.8 times as long as wide, situated in the distal half of trochanteroprefemur.

Leg-bearing segments (Fig. 12 G). Tergite 1 wider than metatergite 2; lateral margins converging backward. Metasternites sub-rectangular; with a deeply mid-longitudinal sulcus. Posterior pair of sub-ovoid pore-fields present in all metasternites from 1 to penultimate. Pore-fields present also on all procoxae and metacoxae from 1 to penultimate. Legs 1 smaller than the others; pretarsus claw-like, reaching ca. 1 / 4 of the length of the tarsus.

Ultimate leg-bearing segment (Fig. 12 H, I). Pretergite and intercalary pleurites separated by distinct sulcus; pretergite ca. 3 times as wide as long on exposed part. Metatergite ca. 1.4–1.8 times as wide as long; sub-trapezoid. Metasternite sub-trapezoid; ca. 1.1 times as wide as long; lateral margins slightly concave to nearly straight, converging backwards; posterior margin ca. 0.4 times as wide as anterior margin; with sparse setae of various sizes. Coxal pores 15–28 on each coxopleuron; opening independently; all sparse on the ventral surface but densely in lateral margin of the metasterniteand some of them covered by that; diameter of the coxal pores similar to that of the respective ducts; setae slightly denser close to the ventral posterior edge of the coxopleuron. Ultimate leg ca. 0.8 times as long as penultimate leg, distinctly swollen, with very dense setae on ventral and lateral sides. Ultimate pretarsus a claw; ca. 0.2 times as long as tarsus.

Postpedal segments (Fig. 12 H). Male: intermediate sternite distinct and exposed; first genital sternite separated from pleurites by distinct sutures; gonopods bi-articulate, with setae; penis conical; anal pores present.

Etymology.

Latin: obliquidentata = slantingly toothed. The specific epithet refers to the oblique basal denticle of tarsungulum. We suggest the Chinese common name as “ 斜齿地蜈蚣 ”.

Remarks.

This new species differs from all other known species of Strigamia in that it has a basal denticle of the tarsungulum that extends obliquely downward, forming an approximately right angle with the internal margin, and the internal and external margins of the tarsungulum are subparallel along the basal part. While its coxal pore count and arrangement resemble those of S. japonica (Verhoeff, 1935) and S. platydentata (Shinohara, 1981) and its forcipular tarsungulum convergence pattern matches that of S. tenuiungulata (Takakuwa, 1938), they can all be unambiguously distinguished by the morphology of the tarsungular basal denticle. S. alokosternum (Attems, 1927), S. hirsutipes (Attems, 1927), S. pusilla (Sseliwanoff, 1884), S. sacolinensis (Meinert, 1870), S. sibirica (Sseliwanoff, 1881), and S. sulcata (Sseliwanoff, 1881) are poorly described in terms of their forcipular segment. Therefore, it can be distinguished from S. alokosternum (Takakuwa 1938, 1940; Bonato et al. 2012) based on the length-to-width ratio of the ultimate leg-bearing segment of the metasternite. It can be distinguished from S. pusilla (Sseliwanoff 1884; Bonato et al. 2012), S. sibirica (Sseliwanoff 1881, 1884; Bonato et al. 2012) and S. sulcata (Sseliwanoff 1881; Bonato et al. 2012) by the number of leg-bearing segments. The new species can be distinguished from S. sacolinensis (Attems 1929; Bonato et al. 2012) based on the density and arrangement of the setae on the metasternite.

Distribution.

China (Jilin Province).