Abavorana decorata comb. nov. (Mocquard, 1890)

Quah, Evan S. H., Grismer, L. Lee, Wood Jr., Perry L., Lim, Kelvin K. P., Imbun, Paul Y. & Anuar, M. S. Shahrul, 2021, An investigation into the taxonomy of Abavorana luctuosa (Peters, 1871) (Anura, Ranidae) and the resurrection of Rana decorata Mocquard, 1890 from Borneo, Vertebrate Zoology 71, pp. 75-99 : 75

Abavorana decorata comb. nov. (Mocquard, 1890)

Decorated Mahogany Frog Figs 5 , 6 , 7A-D , 9C-D

Rana decorata : Mocquard 1890:145-146; Guibé 1950:41

Rana luctuosa (in part): Boulenger 1891:341 & 342, 1912:238, 1920:183 & 184; Flower 1896:904, 1899:896 & 897; Hanitsch 1900:73; Butler 1904:199; Smith 1931:16; Van Kampen 1923:196 & 197; Taylor 1962:451-453; Inger 1954:250, 1966:206-208, 1978:312, 1985:iii, 5, 38, 40, 56, 57, 76; Grandison 1972:66 & 67; Berry 1975:74 & 75, Fig. 50 (right); Matsui 1979:333; Inger & Stuebing 1992:42, 2005:19, 27, 33, 149 & 150; Inger & Tan 1996:563; Inger et al. 1996:363; Malkmus 1994:244; Manthey & Grossmann 1997:111 & 112; Khonsue & Thirakhupt 2001:73; Malkmus et al. 2002: 163-165, figs 159, 160; Das 2006a:5.

Rana (Hylorana) luctuosa (in part): Boulenger 1920:126.

Rana (Hylarana) luctuosa (in part): Van Kampen 1923:196 & 197; Bourret 1942:360; Dubois, 1987: 42.

Hylorana luctuosa (in part): Deckert 1938:144

Rana (Pulchrana) luctuosa (in part): Dubois 1992:326

Pulchrana luctuosa (in part): Frost et al. 2006:369; Fei et al. 2010:33.

Hylarana luctuosa (in part): Manthey 1983:22; Che et al. 2007: 1-13 (by implication); Das et al. 2007:159, 160, 167, 170; Imbun 2014:99.

Abavorana luctuosa : Oliver et al. 2015:186 (in part); Quah et al. 2017: 272-288 (in part); Zainudin et al. 2017:876-891 (in part); Haas et al. 2018:92, 93, 100, fig. 4b.

Hylarana (Abavorana) luctuosa (in part): Inger et al. 2017:147 & 148.

Syntypes.

MNHNP 1889.226-28 from “Bornéo Kina Balu", Sabah (Borneo), Malaysia. ( Guibé 1950) (Fig. 5 ).

Diagnosis.

In addition to its phylogenetic placement (Fig. 1 ), Rana decorata is reassigned as a member of the genus Abavorana based on the combination of having a robust, medium-sized body; no vocal sacs in males; length of 1st finger greater than 2nd finger; disc width to finger width ratios of finger 3 and toe 4 is 1-1.5; dorsolateral fold indistinct or absent; the colour of the dorsolateral line being white or yellow; the humeral gland in males is prominent, raised and centrally positioned on the ventral surface of the upper arm; a weak or absent rictal ridge; outer metatarsal tubercle weak or absent; skin of dorsum smooth or finely shagreened; throat, abdomen and flanks smooth; posterior section of venter and back of the thigh rugose; no pale colouration on the margins of the tympanum; flanks dark-brown or black below the dorsal fold grading into a pale venter ( Inger 1966; Oliver et al. 2015; Quah et al. 2017). Dorsum reddish-orange to rust-brown, encircled by a white or cream coloured dorsolateral line that encircles the snout, canthus rostralis, outer edge of the upper eyelids, and dorsum along the dorsolateral fold to the vent; lower flanks dark-brown or black below the dorsolateral line grading into a paler venter; dorsal colouration of the limbs light-grey or brown with speckling and prominent dark-brown or black bands. Abavorana decorata can be differentiated from its congeners on the basis of its ventral colour pattern which is reticulated in black and white especially on the lower flanks, underside of the limbs (especially hind-limbs) are boldly banded in black and white, and a prominent white streak under the eye and/or tympanum to the corner of the jaw (Figs 5 , 6 , 9C-D ). Adult males with SVL 46.21-56.0 mm, adult females with SVL 29.66-58.42 mm; adult males with SW 9.91-10.71 mm, adult females with SW 6.25-11.68 mm; adult males with IOD 5.59-5.95 mm, adult females with IOD 3.91-6.78 mm; adult males with TD 4.54-4.60 mm, adult females with TD 2.27-5.63 mm; adult males with FL 25.58-26.10 mm, adult females with FL 17.19-31.34 mm (Table 5 ).

Distribution (Fig. 10 ). Endemic to Borneo. The species is known from Sabah state, Malaysian Borneo: Mount Kinabalu, Kampung Kiau Taburi, Danum Valley, Tawau Hills Park, Maliau Basin, Tambunan and Penampang (CalPhotos ID: 0000 0000 0912 1159); Sarawak state, Malaysia Borneo: Kubah National Park (Fig. 7C ) and Bario (Fig. 6A-B ); and West Kalimantan, Indonesia: Melawi Regency (Fig. 7D ). The species is expected to be wider ranging on the island.

Figures

Figure 1. Phylogenetic tree of the genus Abavorana; Maximum likelihood phylogram for species of the genus Abavorana. Nodal support is indicated by Bayesian posterior probability (BPP) / Ultrafast bootstrap (UFboot) respectively.

Figure 5. Syntypes of Abavorana decorata; A & D: Dorsum and venter of MNHN-RA- 1889.226. B & E: Dorsum and venter of MNHN-RA- 1889.227. C & F: Dorsum and venter of MNHN-RA- 1889.228 (Photographs by Christine Reinhardt). G: Original illustration of the syntypes of Abavorana decorata from Mocquard (1890). Illustrations assignable to specimen MNHN-RA- 1889.226 (left) and MNHN-RA- 1889.228 (right).

Figure 6. Examined Abavorana decorata specimens; Dorsal (A & C) and ventral (B & D) pattern of Abavorana decorata from Borneo. A & B (from left to right): FMNH 109935 from Kiau, Mount Kinabalu, Sabah (left), FMNH 109936 from Kiau, Mount Kinabalu, Sabah (middle), FMNH 231052 from Danum Valley Research Center, Lahad Datu District, Sabah (top right), FMNH 128127 from Bario, Sarawak (bottom right). C & D: SP 26873 from Tawau Hills, Sabah (left) and SP 02810 from Maliau Basin, Sabah.

Figure 7. Living specimens of Abavorana decorata and Bornean A. luctuosa; A: Abavorana decorata from Tawau Hills, Sabah, East Malaysia. B: A. decorata from Maliau Basin, Sabah, East Malaysia. C: A. decorata from Kubah National Park, Sarawak, East Malaysia. D: A. decorata from Melawi Regency, West Kalimantan Province, Indonesia. E & F: A. luctuosa from Kubah National Park, Sarawak, East Malaysia. G: A. luctuosa (FMNH 238720) from Sipitang, Sabah, East Malaysia. H: A. luctuosa (FMNH 242883) from Sipitang, Sabah, East Malaysia. (Photographs by Alexander Haas [A, C & E], Paul Bertner [B], Muhammad Aini [D], Chien C. Lee [F], and Robert F. Inger [G & H], Figs G & H © Field Museum of Natural History. Created by Field Museum of Natural History, Amphibian and Reptile Collection and licensed under CC-BY-SA 4.0).

Figure 9. Colour pattern comparison among species of the genus Abavorana; Dorsum (A, C & E) and venter (B, D & F) in life of A. luctuosa (USMHC 2576) (A & B) from Penang Hill, Penang Island, Malaysia, A. decorata from Maliau Basin, Sabah, East Malaysia, Borneo (C & D) and A. nazgul (USMHC 2233) (E & F) from Gunung Jerai, Kedah, West Malaysia. (Photographs by Evan Quah [A, B, E & F] and Stefan T. Hertwig [C & D]).

Figure 10. Distribution map of Abavorana decorata and A. luctuosa in Borneo; Known distribution of Abavorana decorata (red) and A. luctuosa (blue) in Borneo. Star = type locality.