Hemiphyllodactylus bonkowskii, Nguyen & Do & Ngo & Pham & Pham & Le & Ziegler, 2020

Nguyen, Truong Quang, Do, Quyen Hanh, Ngo, Hanh Thi, Pham, Anh Van, Pham, Cuong The, Le, Minh Duc & Ziegler, Thomas, 2020, Two new species of Hemiphyllodactylus (Squamata: Gekkonidae) from Hoa Binh Province, Vietnam, Zootaxa 4801 (3), pp. 513-536 : 516-522

Hemiphyllodactylus bonkowskii sp. nov.

( Figs. 3 , 4 )

Holotype. IEBR 4689 (Field number HB 2014.44), adult male, collected on 15 April 2014 by T. Q. Nguyen, C. T. Pham, H.N. Ngo from a limestone cliff in the corn field (20 o 43.480’N, 104 o 54.344’E, at an elevation of 969 m a.s.l.), Hang Kia Commune , within Hang Kia—Pa Co NR, Mai Chau District, Hoa Binh Province, northwestern Vietnam.

Paratypes. IEBR 4690 (Field number HB 2014.45), adult male ; IEBR 4691 (Field number HB 2014.46), adult female, the same data as the holotype ; IEBR 4692 (Field number HB 2014.2) , IEBR 4693 (Field number HB 2014.3), adult females, collected on 10 April 2014 by T.Q. Nguyen , C . T. Pham, H.N. Ngo from a limestone cliff near the corn field (20 o 43.481’N, 104 o 54.349’E, at an elevation of 970 m a.s.l.) ; IEBR 4749 (Field number HB 2014.40), subadult female, collected on 14 April 2014 by C . T. Pham, H.N. Ngo from a limestone cliff (20 o 43.644’N, 104 o 52.177’E, at an elevation of 933 m a.s.l.) .

Diagnosis. A bisexual taxon; SVL of adult 40.70–48.00 mm; dorsal scale rows 24–27; ventral scale rows 13– 15; postmentals bordering mental and first infralabial, distinctly enlarged; digital lamellae formula 3444 (forefoot) and 4554 (hindfoot); 19 pore bearing femoral and precloacal scales, in a continuous row, absent in females; cloacal spur single, present in both sexes; dorsal trunk pattern yellowish grey; body with a discontinuous light dorsolateral stripe.

Description of holotype. Body dorsolaterally flattened, size small (SVL 45.80 mm), tail length (TaL 35.20 mm), trunk length (TrunkL 23.60 mm), head longer than wide (HeadL 10.50 mm, HeadW 8.58 mm), eye moderate (EyeD 3.05 mm), ear opening oblique (EarD 1.06 mm), nare-eye length (NarEye 3.15 mm), snout-eye length (Sn- Eye 4.85 mm), internarial distance (SnW 1.93 mm). Proportions: TrunkL/SVL 0.52, HeadL/SVL 0.23, HeadW/SVL 0.19, HeadW/HeadL 0.82, SnEye/HeadL 0.46, NarEye/HeadL 0.30, EyeD/HeadL 0.29, SnW/HeadL 0.18, EyeD/ NarEye 0.97, SnW/HeadW 0.22.

Scalation. Rostral very large, wider than high (RW 1.90 mm, RH 1.00 mm), with a shallow suture posteriorly; supralabials 10/10, enlarged from rostral to below eye, smaller in subocular rictus; naris in contact with rostral, first supralabial, supranasal, and two nasals posteriorly on each side; supranasals separated from each other by four small granular internasals; snout flat, covered by granular scales; pupil vertical; ear opening oblique, oval, approximately 35% of the eye diameter, without bordering enlarged scales; infralabials 10/10; mental triangular, wider than long, bordered laterally by first infralabials and posteriorly by two large postmentals; two large postmentals in contact with mental and first infralabials anteriorly; seven chin scales; gular scales small, subimbricate; throat and pectoral scales which grade into slightly larger, subimbricate. Dorsal scales small, granular, 24 or 25 scale rows at midbody contained within one eye diameter, enlarged tubercles absent; ventrolateral folds absent; ventral scales, flat, larger than dorsal scales, 13 scales contained within one eye diameter; enlarged, femoral and precloacal scales; 19 pore bearing femoral and precloacal scales, in a continuous row; cloacal spur one; dorsal surface of fore- and hindlimbs covered with granular scales; terminal two phalanges free, claws absent on first finger and on first toe, present on second to fifth digit of fore- and hindfoot; pads of digits II–V each with large triangular lamellae, digital lamellae formula 3444 (forefoot) and 4554 (hindfoot); lamellae five on first fingers, five on first toes; dorsal caudal scales granular; subcaudals flat, slightly larger than dorsal caudal scales.

Coloration in preservative. Ground color of dorsal surface of head and body yellowish grey; a dark brown streak originating from posterior corner of eye on each side to the neck; neck and dorsum with a row of light spots on each side; dorsal surface of limbs grey with dark bars; upper lips with dark bars; lower lips white; dorsal surface of tail brown with seven light bands; throat white; venter and precloacal region cream with small dark brown dots; testes white, unpigmented. For color and pattern in life see Fig. 3 .

Sexual dimorphism and variation. The females differ from males in the absence of hemipenial swellings at the tail base. The scale counts vary among the type series: scales between supranasals 2–4; supralabials 8–10; infralabials 8–11; chin scales 5–7; dorsal scale rows 24–27; ventral scale rows 13–15; precloacal pores absent in females; lower lips with dark bars and thoat cream with small dark brown dots in two females IEBR 4691, 4692 ( Tables 2, 3, Fig. 4 ).

Distribution. Hemiphyllodactylus bonkowskii sp. nov. is currently known from the type locality in Hang Kia– Pa Co NR, Hoa Binh Province, Vietnam ( Fig. 1 ).

Etymology. We name the new species in honour of Prof. Dr. Michael Bonkowski from the Institute of Zoology, University of Cologne, Germany for his support of our biodiversity research in limestone karst forests in Vietnam and Laos. For the common names we suggest Bonkowski’s Slender Gecko (English) and Thạch sùng dẹp bonkowski (Vietnamese).

Natural history. Specimens were found at night between 19:30 and 22:00, on a limestone cliff in the corn field, approximately 0.5–1.5 m above the ground, at elevations about 970 m. The surrounding habitat was disturbed evergreen karst forest of medium hardwood and shrub ( Fig. 5 ). The humidity was approximately 70–94% and the air temperature ranged from 23 to 29 oC.

Comparisons. We compare the new species from Hoa Binh Province with other members of Hemiphyllodactylus from Vietnam and neighboring countries. For comparisons with other species of Hemiphyllodactylus see Table 4. Hemiphyllodactylus bonkowskii sp. nov. differs from H. banaensis by having fewer scales between supranasals (2–4 vs. 4–11 in H. banaensis ), more dorsal scale rows (24–27 vs. 17–20 in H. banaensis ), and more ventral scale rows (13–15 vs. 9–12 in H. banaensis ); from H. changningensis Guo, Zhou, Yan & Li by having more dorsal scale rows (24–27 vs. 11–15 in H. changningensis ), more ventral scale rows (13–15 vs. 6–8 in H. changningensis ), digital lamellae formula 4554 (hindfoot) (vs. 3444/ 3333 in H. changningensis ); from H. dushanensis by having fewer chin scales (5–7 vs. 8–10 in H. dushanensis ), fewer supralabials (8–10 vs. 11–13 in H. dushanensis ), more dorsal scale rows (24–27 vs. 14–15 in H. dushanensis ), more ventral scale rows (13–15 vs. 8–9 in H. dushanensis ), fewer precloacal and femoral pores in males (19 vs. 24–26 in H. dushanensis ), and the presence of anteriorly projecting arms on postsacral (vs. absence in H. dushanensis ); from H. hongkongensis Sung, Lee, Ng, Zhang & Yang by having a larger size (maximum SVL 48 mm vs. 43 mm in H. hongkongensis ), more dorsal scale rows (24–27 vs. 12–15 in H. hongkongensis ), more ventral scale rows (13–15 vs. 9–10 in H. hongkongensis ), and fewer precloacal and femoral pores in males (19 vs. 24–25 in H. hongkongensis ); from H. huishuiensis Yan, Lin, Guo, Li & Zhou by having fewer chin scales (5–7 vs. 8–10 in H. huishuiensis ), more dorsal scale rows (24–27 vs. 13–15 in H. huishuiensis ), and more ventral scale rows (13–15 vs. 7–9 in H. huishuiensis ); from H. indosobrinus Eliades, Phimmachak, Sivongxay, Siler & Stuart by having a larger size (maximum SVL 48 mm vs. 39.8 mm in H. indosobrinus ), fewer supralabials (8–10 vs. 15 in H. indosobrinus ), fewer dorsal scale rows (24–27 vs. 30 in H. indosobrinus ), more ventral scale rows (13–15 vs. 11 in H. indosobrinus ), and digital lamellae formula 3444 (forefoot) (vs. 4554 in H. indosobrinus ); from H. jinpingensis by having a larger size (maximum SVL 48.00 mm vs. 39.60 mm in H. jinpingensis ), more dorsal scale rows (24–27 vs. 11–12 in H. jinpingensis ), more ventral scale rows (13–15 vs. 5–7 in H. jinpingensis ), fewer precloacal and femoral pores in males (19 vs. 20–24 in H. jinpingensis ), and the presence of anteriorly projecting arms on postsacral (vs. absence in H. jinpingensis ); from H. kiziriani Nguyen, Botov, Le, Nophaseud, Bonkowski & Ziegler by having a larger size (maximum SVL 48 mm vs. 40.8 mm in H. kiziriani ), fewer circumnasal scales (3 vs. 4 in H. kiziriani ), and more precloacal and femoral pores in males (19 vs. 10–13 in H. kiziriani ); from H. longlingensis by having fewer circumnasal scales (3 vs. 4–5 in H. longlingensis ), more dorsal scale rows (24–27 vs. 10–14 in H. longlingensis ), more ventral scale rows (13–15 vs. 6–7), and the presence of anteriorly projecting arms on postsacral (vs. absence in H. longlingensis ); from H. serpispecus Eliades, Phimmachak, Sivongxay, Siler & Stuart by having a larger size (maximum SVL 48.00 mm vs. 41.90 mm in H. serpispecus ), more ventral scale rows (13–15 vs. 10 in H. serpispecus ), digital lamellae formula 4554 (hindfoot) (vs. 3445 in H. serpispecus ), more precloacal and femoral pores in males (19 vs. 11 in H. serpispecus ), and fewer cloacal spurs (1 vs. 2 in H. serpispecus ); from H. typus by having fewer chin scales (5–7 vs. 9–14 in H. typus), more dorsal scale rows (24–27 vs. 12–19 in H. typus), and digital lamellae formula 4554 (hindfoot) (vs. 4454 in H. typus); from H. yunnanensis by having more dorsal scale rows (24–27 vs. 9–18 in H. yunnanensis ), more ventral scale rows (13–15 vs. 6–12 in H. yunnanensis ), digital lamellae formula 3444 (forefoot) and 4554 (hindfoot) (vs. 3333 and 3444, respectively, in H. yunnanensis ), and the presence of anteriorly projecting arms on postsacral (vs. absence in H. yunnanensis ); and from H. zugi by having fewer chin scales (5–7 vs. 9–12 in H. zugi ), fewer supralabials (8–10 vs. 10–13 in H. zugi ), and more dorsal scale rows (24–27 vs. 19–22 in H. zugi ).

Figures

FIGURE 1. Map of sampling sites in Hoa Binh Province, northern Vietnam: 1) Type locality of Hemiphyllodactylus bonkowskii sp. nov. in Hang Kia—Pa Co Nature Reserve; 2) Type locality of Hemiphyllodactylus ngocsonensis sp. nov. in Ngoc Son—Ngo Luong Nature Reserve.

FIGURE 3. The male holotype of Hemiphyllodactylus bonkowskii sp. nov. (IEBR 4689): A) Dorsal view in life, B) Precloacal region with precloacal and femoral pores in a continuous series, C) Subdigital view of right hand, and D) Subdigital view of right foot. Photos: C.T. Pham, Q.H. Do. Scale bar = 1 mm.

FIGURE 4. Hemiphyllodactylus bonkowskii sp. nov. in life: A) The male paratype (IEBR 4690) and B) The female paratype (IEBR 4692). Photos: C.T. Pham.

FIGURE 5. Macrohabitat of Hemiphyllodactylus bonkowskii sp. nov. in Hang Kia—Pa Co Nature Reserve, Hoa Binh Province, Vietnam. Photo: C.T. Pham.