Amolops tanfuilianae, Sheridan & Phimmachak & Sivongxay & Stuart, 2023

Sheridan, Jennifer A., Phimmachak, Somphouthone, Sivongxay, Niane & Stuart, Bryan L., 2023, Systematics of the Lao torrent frog, Amolops cremnobatus Inger & Kottelat, 1998 (Anura: Ranidae), with descriptions of four new species, Vertebrate Zoology 73, pp. 931-956 : 931

Amolops tanfuilianae sp. nov.

Figure 7 "Clade A"

Chresonymy.

Amolops cremnobatus Orlov et al. (2002: 86, part), Chen et al. (2005: 234), Ngo et al. (2006: 84), Stuart (2008: 51), Nguyen et al. (2009: 121, part), Pham et al. (2015: 111), Pham et al. (2016: 40), Wu et al. (2020: 5, part), Brakels et al. (2021: 159), Pham et al. (2022: 171.

Holotype.

NCSM 79949 (field number BLS 15368), adult male, Laos, Xaysomboun Province, Longchaeng District, 19.01807 N, 102.87633 E, 490 m elev., coll. 2045 h on a plant leaf 0.3 m above <1 m wide steep rocky seep flowing into the Nam Ngum River in disturbed semi-evergreen forest on 10 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay.

Paratypes.

Laos, Luang Phabang Province, Phoukhoun District: FMNH 280104, NCSM 77803-04, NCSM 77806 (four adult males), FMNH 280108, NCSM 77805, NCSM 77807 (three adult females), 19.30189°N, 102.57361°E, 1269 m elev., coll. 5 January-9 June 2009 by Somphouthone Phimmachak; NCSM 77809 (one adult male), 19.30103°N, 102.57581°E, 1250 m elev., coll. 8 April 2009 by Somphouthone Phimmachak. - Laos, Xaysomboun Province, Anouvong District, tributary of Nam Ngum River: NCSM 79936-37 (two adult males), NCSM 79940 (one adult female), 18.96260°N, 102.86817°E, 1065 m elev., coll. 23 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79938, NUOL 00030 (two adult females), 18.96346°N, 102.86800°E, 1044 m elev., coll. 23 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79939 (one adult male), 18.96286°N, 102.86802°E, 1054 m elev., coll. 23 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79941, NCSM 79943 (two adult males), NCSM 79942 (one adult female), 18.96227°N, 102.86815°E, 1074 m elev., coll. 23 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay. - Laos, Xaysomboun Province, Hom District: NCSM 86769, NCSM 86772, NUOL 00558, NUOL 00560 (four adult males), NCSM 86768, NCSM 86771, NUOL 00559 (three adult females), Phou Samsao, 18.77802°N, 103.28593°E, 1545 m elev., coll. 16-17 July 2015 by Somphouthone Phimmachak and Sengvilay Seateun; NCSM 86773 (one adult male), NUOL 00563-64 (two adult females), 18.77854°N, 103.28757°E, 1594 m elev., coll. 18 July 2015 by Somphouthone Phimmachak and Sengvilay Seateun; NCSM 99484 (one adult male), Phou Samliam, 18.89780°N, 103.40057°E, 960 m elev., coll. 21 April 2018 by Somphouthone Phimmachak, Sengvilay Seateun, Sinyasone Souvannasy, and Nidarphone Kouangvilaykhoun; NCSM 99486 (one adult male), 18.87535°N, 103.41138°E, 560 m elev., coll. 24 April 2018 by Somphouthone Phimmachak, Sengvilay Seateun, Sinyasone Souvannasy, and Nidarphone Kouangvilaykhoun; NCSM 99485, NUOL 00115-19 (six adult females), 18.89857°N, 103.39857°E, 926 m elev., coll. 22 April 2018 by Somphouthone Phimmachak, Sengvilay Seateun, Sinyasone Souvannasy, and Nidarphone Kouangvilaykhoun. - Laos, Xaysomboun Province, Longchaeng District: NCSM 79948 (one adult male), NCSM 79944-47 (four adult females), 18.96546°N, 102.84858°E, 790 m elev., coll. 24 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79960 (one adult male), 19.04444°N, 102.88918°E, 538 m elev., coll. 14 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79961 (one adult female), 19.09203°N, 102.89792°E, 883 m elev., coll. 16 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79963-66, NCSM 79968-70, NCSM 79975, NUOL 00034-35 (ten adult males), NCSM 79962, NCSM 79967, NUOL 00033 (three adult females), 19.09100°N, 102.89607° E, 885 m elev., coll. 16-18 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay; NCSM 79971 (one adult female), 19.08988°N, 102.89599°E, 887 m elev., coll. 17 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay. - Vietnam, Nghe An Province, Con Cuong District, Pu Mat National Park: FMNH 255604-05 (two adult females), 18.9333 N, 104.7500 E, 300 m elevation, coll. 8 September 1998 by Bryan L. Stuart; ROM 27213-15, ROM 27217, ROM 27229, ROM 27232, ROM 27236-37, ROM 27246 (nine adult males), ROM 27231, ROM 27233-34, ROM 27239-41, ROM 27243-44, ROM 27247 (nine adult females), 18.93833°N, 104.88361°E, 308 m elev., coll. 5-6 June 1995 by Robert W. Murphy et al.; ROM 41614 (one adult male), 18.94167°N, 104.80972°E, 308 m elev., coll. 24 October 1994 by by Robert W. Murphy et al. - Vietnam, Nghe An Province, Que Phong District, Pu Hoat Proposed Nature Reserve: NCSM 79685-86 (two adult males), 19.70865°N, 104.74938°E, 834 m elev., coll. 10 June 2010 by Jodi J. L. Rowley, Trung Tien Cao, Vinh Quang Dau, Huong Thu Phung, Tuan Ngoc Le, Luong Thi Nguyen, Trung Danh Hoang, and Thang Thanh Le. - Vietnam, Nghe An Province, Tuong Duong District, Pu Mat National Park: FMNH 255608 (one adult male), FMNH 255606-07 (two adult females), 19.05000°N, 104.61667°E, 600 m elev., coll. 13 September 1998 by Bryan L. Stuart.

Referred larvae.

Laos, Xaysomboun Province, Longchaeng District: NCSM 79982 (sequenced; nine larvae), 19.09100°N, 102.89607° E, 885 m elev., coll. 16 May 2012 by Bryan L. Stuart, Somphouthone Phimmachak, and Niane Sivongxay. - Laos, Xieng Khouang Province, Phoukout District: NCSM 80179 (two larvae), 19.48167 N, 102.71222 E, 884 m elevation, coll. 27 February 2012 by Maurice Kottelat. - Vietnam, Nghe An Province, Con Cuong District, Pu Mat National Park: AMS R 171526 (sequenced; two larvae), 18.80028°N, 104.84694°E, 647 m elev., coll. 20 June 2008 by Jodi J. L. Rowley, Trung Tien Cao, Vinh Quang Dau, Thu Thi Le, Son Van Chu, and Toan Van Do. - Vietnam, Nghe An Province, Que Phong District, Pu Hoat Proposed Nature Reserve: AMS R 176252 (sequenced; four larvae), 19.69859°N, 104.73171°E, 1352 m elevation, 7 June 2010 by Jodi J. L. Rowley, Trung Tien Cao, Vinh Quang Dau, Huong Thu Phung, Tuan Ngoc Le, Luong Thi Nguyen, Trung Danh Hoang, and Thang Thanh Le.

Etymology.

The specific epithet is a matronym for Tan Fui Lian, Malaysian herpetologist, illustrator of the holotype of A. cremnobatus (figure 1 of Inger and Kottelat 1998), and wife of the late Robert F. Inger who led the description of A. cremnobatus . Fui Lian’s scientific contributions and her generous hospitality to us and innumerable visitors to the Field Museum of Natural History have had immeasurable positive impacts on Southeast Asian herpetology.

Suggested Common Names.

Fui Lian’s Lao torrent frog (English), ຂຽດເກາະຜາລາວຟ ຸຍຫຼຽນ (Khiat Korpha Lao Fui Lian; Lao).

Diagnosis.

A member of the Amolops larutensis group having the combination of 3-4 vomerine teeth reliably present; relative finger lengths I<II<IV<III; mean ± SE SVL of adult males 32.2 ± 1.5 mm (range 28.0-35.3 mm; n = 51) and of adult females 40.0 ± 1.8 (range 35.0-43.1; n = 47); tadpoles with glands near groin in individuals above S30; tadpoles with BL 15.9 ± 2.8 mm (range 12.9-21.5 mm); and tadpoles with BH 5.9 ± 1.1 mm (range 4.6-8.0; n = 16).

Description of holotype.

Habitus moderately slender. Head width approximately equal to head length. Snout weakly pointed in dorsal view. Snout projecting slightly beyond lower jaw in lateral view, sloping obliquely back to lip. No humeral glands apparent. Nostril lateral, nearer to tip of snout than to eye. Canthus rostralis distinct. Lores oblique and slightly concave. Eye diameter roughly equal to snout. Pineal gland absent. Tympanum distinct, round, less than 1/2 of eye diameter, with rim slightly elevated. Rictal glands small, slightly oval. Vomerine teeth closer to each other than to choanae and obliquely angled. Distance between vomerine teeth approximately equal to tooth row width; 3-4 teeth on each side. Tongue cordiform, notched posteriorly. Vocal sac opening. No gular pouch, but some extra skin at corners of lower jaw is present.

Forelimbs moderately slender. Tips of all four fingers expanded into wide discs, with the disc on Finger I notably smaller than discs on the other fingers. Fingers slender. Relative finger lengths I<II<IV<III. No webbing on hands but very minimal basal webbing on outer fingers present. No skin fringe on arms. Subarticular tubercles conspicuous, surfaces rounded, formula 1, 1, 2, 2. One supernumerary tubercle at base of fingers 2-4. Irregular palmar tubercle present. Velvety, well-developed nuptial pads present on dorsal surface of Finger I to distal edge of subarticular tubercle.

Hindlimbs moderately long and slender. Toes slender. Tips of toes expanded into discs with circummarginal grooves. Disc on outermost toe narrower than those on other toes, and barely wider than the toe. Toes fully webbed to base of disc. Thin flap of skin along inner edge of Toe I and outer edge of Toe V. Subarticular tubercles conspicuous, surfaces rounded; formula 1, 1, 2, 2, 2. Inner metatarsal tubercle oval, outer metatarsal tubercle small, round.

Dorsal skin surface with spinose glands and glandular dorsolateral fold. Flanks glandular with few spinose glands just beneath dorsolateral fold. Spinose glands behind tympanum extending to top of arm. Vent glandular.

Measurements of holotype (mm): SVL 33.5, HDL 11.8, HDW 11.6, SNT 4.6, EYE 5.0, IOD 3.5, IND 3.9, TMP 1.9, TEY 0.8, SHK 20.0, TGH 18.6, HND 10.7, FTL 16.9.

Coloration.

In preservative, dorsal coloration dark brown with beige mottling. Dorsal surface of thighs and arms with pale bars on dark brown background. Posterior surface of thighs smooth (not glandular), dark brown with variegated beige pattern. Ventral surface uniformly creamy beige across chin, chest, belly, and underside of arms and legs. Ventral surfaces of feet dark brown, and ventral surfaces of hands dark beige.

In life, from photo of specimen prior to preservation (Fig. 7 ), dorsal surfaces greenish-brown with green mottling. Dorsal surface of thighs and arms with gray bars on greenish brown background. Eye mottled gray on bottom, mottled yellow on top, and orange at anterior and posterior one-quarter. Posterior surface of thighs smooth (not glandular), but with glands near vent extending ventrally and distally. Posterior surface of thighs mainly black with gray mottling, lacking the greenish tinge present on remaining dorsal surfaces. Ventral surface bright white on chin, chest, and belly, with underside of arms and legs transparent. Ventral surfaces of feet dark brown to black, and ventral surfaces of hands dark brown.

Larvae.

Based on a larva at S34 from series NCSM 79982, which includes tadpoles of S25-40, that are assigned to this species based on molecular data (Table S2; Fig. 2 ). Tadpoles of A. tanfuilianae sp. nov. belong to the exotrophic, lotic, gastromyzophorus larval type ( McDiarmid and Altig 1999), with large oral discs ventrally.

HB oval, broadly rounded, wider anteriorly than posteriorly, with weak constriction near line through nares. HB width 57-64% of HBL, widest anterior to eyes. HB flat below with large abdominal sucker. Eyes dorsolateral, pointed laterad. Nares dorsolateral, closer to eyes than tip of snout. Spiracle low on side, tube free of body wall. Tail lanceolate, margins tapering in distal third to narrowly rounded tip; muscle deeper than fins in proximal half. Dorsal fin origin behind HB, origin of ventral fin distal to origin of dorsal fin. HB without spinules. Glands postocular, no glands in fins. Distinct glands ventrally near groin in tadpoles ≥S32.

Oral disc nearly as wide as HB, ventral; labial teeth 9-10(5-9; 5-10)/6(1). A1 at margin of upper lip, short, approximately one-third length of A2, with very small denticles compared to other tooth rows. Papillae short, thick, in single row, absent from middle third of upper lip, but present across entire lower lip. Jaw sheaths with outer surface smooth, upper sheath divided, gap between black halves about equal to depth of keratinized portions; lower jaw sheath in single piece. Jaw sheaths with fine serrae.

Color in preservative of HB brown dorsally and laterally, white ventrally without spots. Caudal muscle brown, with increasing amounts of lighter mottling distally, and white stripe ventrally. Upper fin with melanophores throughout, and lower fin with melanophores in distal half.

Sexual dimorphism.

Males (n = 51) differ from females (n = 47) in being smaller (32.2 ± 1.5 mm SVL vs 40.0 ± 1.8 mm; Table 1 ), and in having paired vocal slits and distinct nuptial pads at base of first finger.

Variation.

Pineal gland sometimes present. Distance between vomerine teeth varies from almost nothing to about the width of one tooth row apart. Males have spinose glands dorsally, but sometimes only weakly spinose (NCSM 81003), and females are glandular but not usually spinose, though occasionally females will be spinose or weakly spinose (NCSM 79971 and 80134, NUOL 00033, 00116, 00118, 00559, 00563). Glandular dorsolateral fold sometimes very faint. When spinose glands are present on the flanks, they are restricted to the upper third to quarter of the flank. Spinose glands behind tympanum extending to top of arm present in all females, and present but sometimes weak in males. Dorsal coloration ranges from dark brown to black with beige mottling. All individuals have more dark than light patches, and almost no individuals have thick beige patches. Ventral surfaces may be entirely beige or may be beige under thighs and arms but creamy white on chin, chest, and belly. Chin and chest may lack dark markings, or may have some dark stippled reticulations, but the entire ventral surface is never dark or marked.

Distribution and natural history.

This species is known from clear streams with torrents in Luang Phabang, Xieng Khouang and Xaysomboun Provinces of northern Laos and Nghe An and Thanh Hoa Provinces of northern Vietnam.

Comparisons.

Amolops tanfuilianae sp. nov. differs from A. cremnobatus , A. sengae sp. nov., and A. attiguus sp. nov. by having a larger number (3-4) of vomerine teeth (2-3 in A. cremnobatus , A. sengae sp. nov., and A. attiguus sp. nov.) that are reliably present (faint or sometimes absent in A. cremnobatus , A. sengae sp. nov., and A. attiguus sp. nov.); and females with larger SVL (Table 1 ). Amolops tanfuilianae sp. nov. differs from A. kottelati sp. nov., A. sengae sp. nov., and A. attiguus sp. nov. by having relative finger lengths I<II<IV<III (I<IV<II<III in A. kottelati sp. nov., A. sengae sp. nov., and A. attiguus sp. nov.). Amolops tanfuilianae sp. nov. further differs from A. sengae sp. nov. by having spinose glands above the arm usually present (absent in A. sengae sp. nov.). Amolops tanfuilianae sp. nov. further differs from A. cremnobatus , A. sengae sp. nov., and A. kottelati sp. nov. by having tadpoles with relatively smaller BH (ANOVA F = 4.16, df = 3, P = 0.02; Table 2 ). Amolops tanfuilianae sp. nov. further differs from A. kottelati sp. nov. by having tadpoles with smaller BL (Table 2 ). Amolops tanfuilianae sp. nov. further differs from A. cremnobatus by having tadpoles with opaque glands on the ventral surface near the vent, proximal to the legs, in tadpoles at S32 or greater ( Inger and Kottelat 1998; Fig. 8 ).

Figures

Figure 2. Fifty percent majority-rule consensus phylogram resulting from partitioned Bayesian analysis of 3,669 aligned characters of the mitochondrial 16 S, mitochondrial ND 2 and flanking tRNAs, nuclear NCX 1, and nuclear tyrosinase genes from Amolops frogs. Trees were rooted with Staurois latopalmatus. Numbers at nodes are Bayesian posterior probabilities (left) and bootstrap values ≥ 50 from a separate maximum likelihood analysis (right). Additional voucher and locality data for samples are provided in Table S 2 and Table S 3.

Figure 7. Amolops tanfuilianae sp. nov. NCSM 79949 in life (top row) and in preservative (bottom row).

Figure 8. Tadpoles in preservative, showing dorsal (left) and ventral (right) views. A Amolops tanfuilianae sp. nov., NCSM 79982; B A. cremnobatus, FMNH 252863; C A. kottelati sp. nov., NCSM 87612; D A. sengae sp. nov. NUOL 01596.