Plagiopholis styani ( Boulenger, 1899 )

Plagiopholis styani ( Boulenger, 1899) View in CoL

Note.

G. A. Boulenger described Plagiopholis styani in 1899, based on two specimens, BMNH 1946.1.14.11 -12 ( Boulenger 1899), but did not designate a holotype. Therefore, we designate the adult male specimen, BMNH 1946.1.14.11 , as the lectotype and the specimen BMNH 1946.1.14.12 as the paralectotype due to it being a juvenile and the morphological characters not being stable.

Lectotype.

BMNH 1946.1 .14.11 , adult male, collected by J. D. La Touche, from Kuatun (= Guadun Village , Wuyishan City), Fukien (= Fujian Province), China (Fig. 3 View Figure 3 ).

Paralectotype.

BMNH 1946.1.14.12 , juvenile female, with the same collection information as the lectotype .

Referred specimens

(n = 9): CIB 10194 (field number 64 I 6669, adult male), FJNU 3625004 ( adult male), FJNU SR ( adult male), FJNU 3625005 ( adult female), FJNU 3525002 ( adult female), FJNU 3625006 ( adult female) from Wuyishan City , Fujian Province, China ; WYS 2024001 ( adult male) from Mt. Huanggang (the main peak of the Wuyi Mountains), Yanshan County, Jiangxi Province, China ; ZJFRR 202207001 ( subadult male) from Anji County, Zhejiang Province, China ; and ZJFRR 202407001 ( adult female) from Lin’an District , Zhejiang Province, China .

Diagnosis.

Plagiopholis styani can be distinguished from other species within Plagiopholis by the combination of the following morphological characters: (1) no loreal (rarely 1), posterior nasal forming a suture with the single preocular; (2) two postoculars; (3) temporals 2 + 2 (rarely 2 + 1); (4) 6 (rarely 7) supralabials, the 3 rd and 4 th entering the eye; (5) 6 (rarely 5) infralabials; (6) maxillary teeth 20–21 in males and around 18 in females; (7) dorsal scale smooth and rows 15-15 - 15; (8) ventral scales 114–121 in males and 116–122 in females; (9) anal entire; (10) subcaudal scales, 26–30 in males and 23–28 in females; (11) longer tail 42.36–51 mm (mean 45.42 mm) in males and shorter tail 32.6–44.15 mm (mean 40.59 mm) in females; (12) higher TAL / SVL ratio of 0.15–0.17 (mean 0.16) in males and smaller TAL / SVL ratio of 0.12–0.15 (mean 0.14) in females; (13) hemipenis half divided, bilaterally symmetrical, the truncus smooth throughout with almost no spinules; (14) a wide, black-brown blotch is present on the neck, often pentagonal, sub-annular, or sagittate-shaped, across 3–6 dorsal scale rows; (15) dorsal surface of the body is brick-red, with some dorsal scale edges black, forming a faint reticulated pattern.

Redescription of the lectotype.

Measurements and scalation. An adult male with TL 347 mm ( SVL 303 mm and TAL 44 mm); tail relatively short, TAL / TL ratio of 0.13, and TAL / SVL ratio of 0.15; body slender and small; head slightly distinct from the neck; HW 8.46 mm; HL 12.41 mm; eye moderate, ED 2.49 mm; rostrum triangular, wider than high, slightly visible from above; internasals and prefrontals paired; frontal haxagonal, longer than wide, a little shorter than the parietals; PRO 1 / 1, PO 2 / 2; loreal absent; TEMP 4, arranged in two rows (2 + 2 / 2 + 2); SL 6 / 6, the 3 rd and 4 th entering the eye, the 5 th and 6 th largest; 2 pairs of chin-shields; IL 5 / 6, the 1 st to 3 rd touching the first pair of chin shields. DSR 15-15 - 15, all smooth, including the outermost row on both sides; VS 114, SC 27, CP entire.

Coloration and pattern. The dorsal surface of the head is reddish-brown, scattered with small black spots. The labial scales are light yellow with black edges on both sides. A blackish-brown subpentagonal blotch is present on the neck, pointing toward the head, and the widest part across four dorsal scale rows. Dorsal surface of the body is reddish-brown, with some dorsal scale edges outlined in black, forming a subtle reticulated pattern. Ventral and subcaudal scales are light yellow, with small dark brown spots on both sides (Fig. 3 View Figure 3 ).

Head scalation. SL 6 / 6 (rarely 7), IL 6 (rarely 5); loreal absent or rarely present (1 / 12 specimens); PRO 1, PO 2; TEMP 2 + 2, rarely 2 + 1 (1 / 12 specimens).

Dentition. Based on two male specimens ( CIB 10194 and ZJFRR 202207001) and one female specimen ( ZJFRR 202407001) examined in this study and Pope (1935). Maxillary teeth 20–21 in males and 18 in females, without diastema; except for the first 2–4 being smaller, the rest are nearly equal in size.

Body scalation. DSR 15-15 - 15, all smooth, including the outermost row; VS 114–121 in males, and 116–122 in females; SC 26–30 in males, and 23–28 in females; CP entire.

Coloration in life. In life, the dorsal surface of the head is deep reddish-brown, sometimes scattered with small black-brown spots. The labial scales are creamy-white with black edges on both sides. A wide black-brown blotch is present on the neck, often pentagonal or irregularly ring-shaped, across 4 to 6 dorsal scale rows. Dorsal surface of the body brick-red, with some dorsal scale edges black, forming a faint reticulated pattern. The ventral and subcaudal scales range from creamy white to pale yellow, sometimes with small dark brown spots along the sides (Fig. 4 View Figure 4 ).

Coloration in preservation. In preservation, the coloration still resembles the specimen in life, except that the coloration of dorsum further deepens, and the background color of the venter becomes uniform pale yellow (Figs 3 View Figure 3 , 5 View Figure 5 ).

Hemipenis. Description based on the everted left organ of the subadult male specimen ZJFRR 202207001 (Fig. 6 View Figure 6 ). When fully everted, the hemipenis is Y-shaped, bilaterally symmetrical, extends to SC 8, and bifurcates at lower 4 / 7.

Truncus is smooth, with almost no visible spinules; the spine ornamentation starts at the base of each branch. On the asulcate surface, each branch has a well-developed, calcareous basal hook, and the upper part with dense, medium-sized spines. The spines gradually decrease in size distally, reaching nearly half of the branches, then merging into thorny calyces. The calyx area extends to the distal end of each branch. Sulcate surface is similar to the asulcate surface, except for the absence of basal hook. The sulcus spermaticus is divided, extending centrifugally to the tip of each branch, and the sulcus lips are visible and slightly raised.

Variation.

See Table 3 View Table 3 and Figs 3 View Figure 3 – 5 View Figure 5 for the details. The longest known male specimen has a TL of 353 mm ( WYS 2024001 ; SVL 302 mm, TAL 51 mm), and the longest known female has a TL of 406 mm ( KIZ 20180002 ; SVL 359 mm, TAL 47 mm). Tail relatively short, TAL / SVL ratio of 0.15–0.17 (mean 0.16) in males and 0.12–0.15 (mean 0.14) in females.

Distribution and natural history.

Plagiopholis styani have been found in Lin’an District of Hangzhou City, Anji County of Huzhou City in Zhejiang Province, and the Wuyi Mountains at the border of Fujian and Jiangxi Provinces (data corrected based on the results of the present study). According to the morphological data recorded in literature, distribution records from southern Anhui and northern Jiangxi Province might also belong to this species ( Pope 1934; Chen 1991; Zhao et al. 1998; Zhao 2006). These regions are part of the mid-subtropical monsoon climate zone, characterized by distinct four seasons, warm and humid conditions ( Zheng et al. 2013). This species is oviparous and distributed within an altitude range of 520–1359 m. They are commonly found in mid-subtropical evergreen broad-leaved forests and bamboo forests in this altitude range.

Pope (1929, 1935) documented the Fukien (now Fujian Province) population ( Plagiopholis styani ) to be found in the high forests and bamboo groves in the region of the type locality, which is consistent with our findings. He documented the stomachs of three Chungan Hsien (now Wuyishan City) specimens ( P. styani ), which contained a lot of gritty dirt suggestive of an earthworm diet. In addition, he recorded a female containing seven eggs, one of which measured 15.5 × 5.5 mm. Based on this observation, the species is inferred to be oviparous.