Species New to Science's Journal

[Herpetology • 2025] Amolops spicalinea • A New Species of Amolops monticola group (Amphibia: Ranidae) from Hoang Lien Range, northwest Vietnam

Amolops spicalinea

Nguyen, Tapley, La & Rowley, 2025

Hoang Lien cascade frog | Ếch bám đá hoàng liên sơn || DOI: doi.org/10.11646/zootaxa.5594.3.3

Abstract

Of the 19 species of Amolops reported from Vietnam, 10 are known to occur in the Hoang Lien Range in northwest Vietnam. During field surveys in the Hoang Lien Range, we collected individuals from a population of Amolops that we could not assign to any known species; morphological and molecular data assign these individuals to the Amolops monticola group and we describe a new species to science, Amolops spicalinea sp. nov., in reference to a line of horny spinules running along the body below the dorsolateral fold in males. The new species is morphologically and molecularly most similar to Amolops bellulus from Yunnan Province, China but is distinguished from A. bellulus and other congeneric species by a combination of the following characters: (1) SVL of adult males 46.6–52.2 mm, N=3; adult females 60.1–63.0 mm, N=3; (2) vomerine teeth in two oblique rows between choanae; (3) tympanic annulus visible; (4) all finger and toe tips expanded to discs with circummarginal grooves present; (5) skin smooth, except for lateral surfaces of head, below the dorsolateral fold, and the area surrounding cloaca where the texture varies from tiny spinules to large tubercles; (6) dorsolateral fold present with horny spinules along the lower half in males; (7) creamy-white lip stripe extending from tip of snout, terminating in a broken, rugose line above axilla; (8) dorsum reddish brown or greenish brown with numerous small black spots; flanks yellowish brown to dark brown; ventral surface of body orange-yellow with small brown spots present on chest and throat; (9) interdigital finger webbing absent; toes fully webbed to discs except on Toes IV where webbing reaches discs as a fringe, webbing formula: I0–0II0–0III0–1+IV1+–0V; (10) outer metatarsal tubercles absent; (11) vocal sac absent in males, and (12) nuptial pad velvety without spines. Our phylogenetic analysis using 16S ribosomal RNA mitochondrial gene and cytochrome c oxidase subunit 1 (CO1) genes show that Amolops spicalinea sp. nov. is sister to Amolops bellulus 2 from Yunnan, China. The new species is currently known from only three localities in the Hoang Lien Range between 2288–2493 m asl and is threatened by habitat loss and degradation. This species likely qualifies for being assessed as Endangered in accordance with the IUCN Red List of Threatened Species categories and criteria (B1ab).

Amphibia, amphibians, anura, cascade frog, Fansipan, Nam Kang ho tao, Pu ta Leng

Amolops spicalinea sp. nov. adult male holotype ITBCZ 3648.
(A) Dorsolateral view in life, (B) ventral view under sedation, (C) view of nuptial pad on first right finger under sedation, and (D), view of cloaca and base of thighs to illustrate glandular character under sedation. Not to scale.

Dorsolateral and ventral view of paratypes of Amolops spicalinea sp. nov. in life.
(A and B) adult male ITBCZ 3649, (C and D) adult male ITBCZ 3652,
(E and F) adult female ITBCZ 3650, and (g and h) adult female ITBCZ 3651.

Amolops spicalinea sp. nov.

Diagnosis. Amolops spicalinea sp. nov. is placed within the Amolops monticola group based on the following morphological characters: Finger I shorter than Finger II; true dorsolateral folds present (not formed by incomplete series of glands); skin smooth; lateral sides of head dark, with light-colored upper lip stripe extending to shoulder (jiang et al. 2021; Patel et al. 2021; Stuart et al. 2010; wu et al. 2020). the new species can be diagnosed from congeneric species by the combination of the following characters: (1) SVL of adult males 46.6–52.2 m, N=3; adult females 60.1–63.0 mm, N=3; (2) vomerine teeth in two oblique rows between choanae; (3) tympanic annulus visible; (4) all finger and toe tips expanded to discs with circummarginal grooves present; (5) skin smooth, except for lateral surfaces of head, below the dorsolateral fold, and the area surrounding cloaca where the texture varies from tiny spinules to large tubercles; (6) dorsolateral fold present with horny spinules along the lower half in males; (7) creamy-white lip stripe extends from the tip of the snout terminating in a broken, rugose line above axilla; (8) dorsum reddish brown or greenish brown with numerous small black spots; flank yellowish brown to dark brown; ventral surface orange-yellow with brown spots present on chest and throat; (9) interdigital finger webbing absent; toes fully webbed to discs except on toes IV where the webbing reaches the discs as a fringe, webbing formula: I0–0II0–0III0–1+IV1+–0V; (10) outer metatarsal tubercle absent; (11) males vocal sacs absent, and (12) nuptial pad velvety without spines.

Etymology: Specific epithet “spicalinea” from spica, the Latin word for a point or ear of grain and lineata, the Latin noun meaning line or thread in reference to the line of spinules running along the body, below the dorsolateral fold in males. We suggest common name as Hoang Lien cascade frog (English) and Ếch bám đá hoàng liên sơn (Vietnamese).

habitat of Amolops spicalinea sp. nov. in the hoang Lien Range.
(A) Collection site on Mount Nam Kang ho tao, Lao Cai Province, (B) Collection site on Mount Pu ta Leng, Lao Cai Province, (C) Male Amolops spicalinea sp. nov. in situ ITBCZ 3649 on tree branch, 2.0 m above stream, Mount Pu ta Leng, Lao Cai Province.

Luan Thanh NGUYEN, Benjamin TAPLEY, Toi Van LA and Jodi J. L. ROWLEY. 2025. A New Species of Amolops monticola group (Amphibia: Ranidae) from Hoang Lien Range, northwest Vietnam. Zootaxa. 5594(3); 485-508. DOI: doi.org/10.11646/zootaxa.5594.3.3 [2025-03-03]