Rhacophorus boeadii, Hamidy & Riyanto & Munir & Gonggoli & Trilaksono & Mcguire, 2025

Rhacophorus boeadii sp. nov.

( Figs. 4–6 View FIGURE 4 View FIGURE 5 View FIGURE 6 )

Holotype. MZB Amph 31070 ( Figs. 4A View FIGURE 4 , 5 View FIGURE 5 A-D), an adult male from near to the Danau [lake] at post 6 ( Fig. 9A View FIGURE 9 ), Gunung [mount] Katopasa , Desa [village] Mire , Kecamatan [sub-district] Ulu Bongka , Kabupaten [regency] Tojo Una-una, Provinsi [province] Sulawesi Tengah, Sulawesi Indonesia (1°11’21.6” S, 121°26’29.7” E, 1471 m a.s.l.) collected by A. Hamidy, J.A. McGuire, A. Riyanto, and Wahyu Trilaksono at 11:00 on 20 August 2017. GoogleMaps

Paratypes: 21 specimens, 11 adult males: MZB Amph 30883, MZB Amph 30884, MZB Amph 30887, MZB Amph 30888, MZB Amph 30889, MVZ Herp 292819, MVZ Herp 292820, MVZ Herp 292821, MVZ Herp 292822, MVZ Herp 292823, MVZ Herp 292824 ; eight adult females: MZB Amph 30880, MZB Amph 30882, MZB Amph 30885, MZB Amph 30886, MZB Amph 30890, MVZ Herp 292825, MVZ Herp 292826, MVZ Herp 292827: locality, collection time, and collector are the same as for the holotype; an adult female ( MZB Amph 26641), and an adult male ( MZB Amph 26642) from Gunung [mount] Gandang Dewata , Desa [village] Tondok Bakaru , Kecamatan [sub-district] Mamasa , Kabupaten [regency] Mamasa, Provinsi [province] Sulawesi Barat, Sulawesi, Indonesia (02° 52’53.1” S 119° 22’57.0” E 1642 m a.s.l.) collected by Syaripudin and A. Hamidy on 26 April 2017 at 19:00 GoogleMaps .

Etymology. We dedicate the specific name to late Drs. Boeadi. He is an Indonesian herpetologist, mammalogist, naturalist, and former staff member of the Museum Zoologicum Bogoriense. He collected many samples of fauna that were deposited in MZB, and his contributions to the advancement of zoological sciences in Indonesia have left a lasting impact.

Diagnosis. The new species is placed in the genus Rhacophorus based on the possession of these following characters: presence of intercalary cartilage between terminal and penultimate phalanges of digits, terminal phalanges of finger and toes Y-shaped, tips of the digits expanded into large disks bearing circum-marginal grooves, webbed fingers, horizontal pupil, and the skin not co-ossified to scull ( Duellman and Trueb 1986; Liem 1970; Brown and Alcala 1994; Malkmus et al. 2002; Inger and Stuebing 2005). Rhacophorus boeadii sp. nov. can be distinguished from its congeners by the combination of the following characters: medium size (SVL adult males [n=12] 40.4–44.6 mm, adult females [n=9] 48.1–54.2 mm); snout sharply pointed in males, sloping; canthus rostralis sharp; vomerine teeth present in two oblique series; tympanum visible; supra tympanic fold thick and conspicuous; nuptial pad on male presence; yellowish gland on the shoulder; dark blotching on ventral surface of chin and chest, lateral side of forelimbs, and hind-limbs; dorsal skin coarsely granular with white-tipped keratinized asperities; flank with white blotched pattern; dermal flaps on limbs absent, only weak crenate fringes present on the postaxial side of the distal half of lower arm; and heel without dermal appendage.

Description of holotype (in mm). Body size medium (SVL 42.0 mm); head longer (HL 13.4; 36.6 % SVL) than wide (HW 12.0; 33.1 % SVL); snout pointed in dorsal view, projecting over the lower jaw in lateral view, canthus rostralis sharp and distinct, curved in dorsal view; lore concave; nostril slightly protuberant, positioned dorsolaterally without a flap of skin, closer to snout than to eye; internarial distance (IND 3.1; 7.5 % SVL) smaller than interorbital distance (IOD 4.9; 11.6 % SVL); interorbital distance slightly wider than upper eyelid width (UEW 4.2; 9.9 % SVL); pineal spot absent; pupil elliptical, horizontal; eye large (ED 6.2; 14.8 % SVL) about five and one-half times tympanum-eye length (TEL 1.12; 2.7 % SVL); tympanum distinct, circular, about one-third of eye diameter (TD 2.0; 4.9 % SVL) and twice tympanum-eye length; supra tympanic fold distinct, elevated from posterior edge of eye to above arm insertion; choanae circular; vomerine teeth present in two oblique series; vocal sac median, subgular; vocal slit present on both sides near corner of mouth; tongue lanceolate, attached anteriorly and deeply notched posteriorly.

Forelimbs slender, lower arm and hand length (LAL 22.1; 52.6 % SVL), relative finger lengths I<II<IV<III; length of the first finger 17.2 % SVL; finger moderately webbed, webbing formula I 3–2¾ II 1–2¼ III 1¾–1½ IV ( Fig. 5B View FIGURE 5 ); sub-articular tubercle rounded, formula 1–1–2–2; supernumerary tubercle distinct; inner palmar tubercle oval (IPTL 2.8; 6.8 % SVL); outer palmar tubercle oval, distinct; nuptial pad present, dark, with granules, positioned on distal edge of oval inner metacarpal of first finger; additional single small tubercle present on preaxial side of the joint between the metacarpal and proximal phalanx of first finger ( Fig. 4D View FIGURE 4 ); dermal fringe on fingers absent, weakly present on the postaxial side of the distal half of lower arm; tips of all fingers expanded into a large disk with circum-marginal and transverse palmar grooves; disk of third finger (3FDW 2.6; 6.2 % SVL) is wider than the disk of the fourth finger (4FDW 2.3; 5.4 % SVL), about one-third of tympanum diameter and nearly half eye diameter.

Hind limbs slender; tibia length (TL 21.3; 50.7 % SVL) longer than foot length (FL 18.5; 44.0 % SVL) and slightly longer than thigh (THL 21.2; 50.5 % SVL); heels overlapping when limbs are held at right angle to body; dermal flap along tibia, tarsus and foot absent, weak fringe present on postaxial edge of fourth finger and fifth toe; relative length of toes I<II<III<V<IV; toe webbing formula I 1–1½ II 1–2 III 1–2 IV 1½–1 V ( Fig. 5C View FIGURE 5 ); round, clearly distinct protuberant sub-articular tubercles on all toes, formula 1–1–2–3–2; supernumerary tubercles indistinct; inner metatarsal tubercle oval, dark, well-developed and notably protuberant (IMTL 1.5; 3.6 % SVL), about one-quarter length of first toe (1TOEL 6.8; 16.3 % SVL); tips of toes expanded into rounded disks with distinct circum-marginal grooves; width disk of fourth toe 4.6 % SVL.

Dorsal surfaces of the head including upper eyelid, body, forelimbs, and hind-limbs coarsely granular with white-tipped keratinized asperities; dorsal surface of anterior part of the head and lower arm more finely granular than other surfaces; lateral surfaces of head, body, forelimbs, and hind-limbs smooth; heel without appendix; ventral surface of chin, chest, and abdomen finely areolate; cloacal region with small densely spaced tubercles; supra cloacal dermal ridge absent.

Coloration. In life, dorsal surface of body dominated by olive green marbled with dark brown, dorsal surface of limbs dominated by brown marble grading to light brown on anterior and posterior sides of limbs ( Fig. 4A View FIGURE 4 ); iris gold, pupil dark; lateral side of head and body dominated by dark brown color, additional indistinct whiteyellowish blotches present on lateral sides of head and body, bright-yellowish blotches present in groin and axilla regions; yellowish gland present on dorsal part of the shoulder; dorsal surface of proximal portion of upper arm with irregular yellowish blotching. Ventral surface of throat and chest bright whitish with dark irregular markings, becoming brownish on mental region; palmar surfaces, forelimbs, inguinal region, and hind-limbs pinkish; dark gray webbing on fingers and toes. In preservative, the color pattern remains (5A-D); however, green color on dorsum faded to bluish, dark brown colored parts have become black; outer side of limbs white-cream, and ventral surface white-cream.

Variation. All individuals of the type series were very similar in external morphology and body proportions (measurement summary of the type series is presented in Table 2 View TABLE 2 and Table 3 View TABLE 3 ). The additional small tubercle on the preaxial side of the joint of the first finger ( Fig. 4D View FIGURE 4 ) is absent in all paratypes. The coloration of the specimens comprising the type series from Mount Katopasa is similar to one another, with just slight differences. For example, some individuals have a higher portion of green on the dorsum and more distinct large dark brown blotches on the thigh and femur ( Fig. 4A, C View FIGURE 4 ). Two paratypes (MZB Amph 26641-42) from Mount Gandang Dewata have light brown dorsal coloration, are brighter yellowish on the flanks of the body, and the iris color is brighter with yellowish coloration on the edge ( Fig. 4B View FIGURE 4 ). The gravid female paratype (MZB Amph 23613) had unicolor cream ovaries.

Larva (in mm). A single specimen (MZB Amph 31071) at Gosner stage 25 ( Fig. 6 View FIGURE 6 A-C), collected by A. Hamidy and Wahyu Trilaksono at a lake at pos 6, Gunung Katopasa, same with holotype locality (see Table 9 View TABLE 9 ). Body stocky, depressed dorsoventrally (TTL 32.5; BL 12.5), tapering to snout, slightly wider than its length (BW 7.5, 23.1 % TTL, BH 7.4, 22.8 % TTL); body contour ovoid in dorsal view; snout rounded in lateral view with characteristic elevation dorsal to the nares and a bulge just dorsal to the oral disk; oral disk in subterminal position, cup-like, not visible in dorsal view (ODW 2.3; 7.1 % TTL); upper labial lacking papillae except in corner of mouth on each side; lower labial full of papillae; labial tooth row formula 5(3–5)/3(1); nares positioned dorsolaterally (SN 0.9; 2.8 % TTL); eyes positioned dorsolaterally (ES 3.3; 10.2 % TTL), not visible from ventral view; interorbital distance (IOD 4.6; 14.2 % TTL) about two times length of internarial distance (IND 2.3; 7.1 % TTL); tail convex, slightly higher (TMH 4.0; 12.35 % TTL) than wide (TMW 3.4; 10.5 % TTL), about more than half of the total length (TAL 20.0; 61.5 % TTL), with its beginning clearly marked in lateral view; dorsal fin originating at same level as tail muscles at trunk-tail junction and ventral fin connected broadly to the trunk; tail height increases gradually, reaching its maximum at mid-tail (MTH 7.7; 23.7 % TTL), tapering gradually to the tip; upper fin (UFH 2.4; 7.4 % TTL) wider than lower fin (LFH 1.9; 5.8 % TTL). In life, background color of dorsal body yellowish-pale with irregular large dark blotches; tail yellowish-pale with dark dots, densely on mid-tail to end of tail; ventral of body nearly translucent with very small yellowish-white and dark dots. In preservative, the yellowish-pale color fades and becomes grey, but the dark blotches unchanged.

Call description: The call contains of 2–8 pulses ( Fig. 7 View FIGURE 7 ) of increasing intensity, pulse durations 5.0–15.0 ms (mean ± SD = 8.5 ± 1.88, n=9), pulse intervals 95.0–404.0 ms (mean ± SD = 133.7 ± 54.71, n=4), pulse periods from 104.0–414.0 ms (mean ± SD = 141.8 ± 55.04, n=4), call durations from 144.0–1274.0 ms (mean ± SD = 579.1 ± 354.40, n=9), call intervals 5729.0–37755.0 ms (mean ± SD = 22709.3 ± 11458.47, n=9), call periods 6655.0– 37899.0 ms (mean ± SD = 2328.9 ± 11388.73, n=9), and dominant frequency ranged from 1125–1500 Hz (mean ± SD = 1394.0 ± 170.72, n=9).

Morphological Comparisons. Rhacophorus boeadii sp. nov. is easily distinguished from all Rhacophorus species of the Malay Peninsula, Greater Sunda Islands, and the Philippines ( R. baluensis , R. borneensis , R. nigropalmatus , R. norhayatiae , R. pardalis , R. reinwardtii , R. barisani , R. bifasciatus , R. poecilonotus , R. margaritifer , R. catamitus , R. indonesiensis , R. bengkuluensis , R. bipunctatus , R. modestus ) by the absence of a projection on the heel (vs. present). Moreover, from R. nigropalmatus , R. borneensis , R. norhayatiae , R. baluensis , R. pardalis , R. reinwardtii , and R. barisani , the males of the new species have smaller body size (vs. exceeding 50 mm SVL, Table 10 View TABLE 10 ). The females of these species (including R. bifasciatus , R. poecilonotus and R. margaritifer ) also exceeded 60 mm, differentiating them from the new species. Rhacophorus boeadii sp.nov. is unlike R. catamitus and R. indonesiensis by having a larger body size (vs. less than 35 mm SVL, Table 10 View TABLE 10 ). Rhacophorus boeadii sp. nov. differs from R. bengkuluensis by having a sloping snout in lateral view with a pointed edge (vs. slope but not pointed: Streicher et al. 2014) and eyelid with distinct tubercles (vs. indistinct: Streicher et al. 2014). Unlike R. modestus , the new species has fully-webbed toes (vs. webb on the fourth toe only reaching the distal subarticular tubercle).

Rhacophorus boeadii sp. nov. is distinguished from other Sulawesian Rhacophorus by a combination of characters. From R. georgii by much smaller body size, SVL 40.4–44.6 mm in males, SVL 48.1–54.2 mm in females (vs 51.6–75.2 mm in males, 82.3˗93.8 mm in females); absence of Protuberant bony occiPital crest (vs. Present, Fig. 8A, D View FIGURE 8 ); males flank covered by coarsely granular, white-tipped asperities (vs. absent, Fig. 8I, L View FIGURE 8 ); snout sloped in lateral view (vs. angular, Fig. 8A, D View FIGURE 8 ), absence of a small pointed projection at the anteriormost tip of snout (vs. present, Fig. 8A, D View FIGURE 8 ); dermal flaps absent on limbs, only weak crenate fringes present on the postaxial side of the distal half of lower arm (vs. well-developed); absence of dermal appendage on the heel (vs. present); absence of distinct reticulated pattern on the flank (vs. present).

Rhacophorus boeadii sp. nov. is distinguished from R. edentulus by having larger body size, SVL 40.4–44.6 mm in males (vs. 27.8–32.7 mm); distinct coarsely granular, white-tipped keratinized asperities on dorsal skin of males (vs. indistinct, Fig. 8I, J View FIGURE 8 ); snout sloped in lateral view (vs. truncate, Fig 8A, B View FIGURE 8 ); web on finger II to III reaches distal subarticular tubercles (vs. not reaching distal subarticular tubercles, Fig. 8Q, R View FIGURE 8 ); cloaca has many tubercles (vs. absent, Fig. 8M, N View FIGURE 8 ); male flank with white blotched pattern (vs. immaculate yellowish-white); dark blotching on ventral surface of chin and chest, lateral side of forelimbs and hind-limbs (vs. immaculate whitish); having a foam nest type (vs jelly nest type in R. edentulus ( Putri et al. 2018) ; a shorter ratio of head length, RHL 34.5–36.6 % SVL (vs. 35.8–41.6 % SVL); a narrower head width ratio, RHW 27.6–33.7 % SVL (vs. 32.5–37.0 % SVL); slightly longer of snout length ratio, RSL 4.7–8.2 % (vs. 4.6–6.6 % SVL); a sharp-pointed snout in males (vs. rounded); presence of vomerine teeth (vs. absent); a narrower interorbital length ratio, RIOD 10.5–12.5 % SVL (vs. 12.4–14.7 % SVL); a narrower eye length and eye diameter ratio, REL 13.4–17.1 % SVL, RED 12.5–14.8 % SVL (vs. REL 16.1–18.5 % SVL, RED 13.7–17.1 % SVL); a shorter tympanum-eye length ratio, RTEL 1.8–3.2 % SVL (vs. 3.2–5.2 % SVL); a larger range of ratio inner palmar tubercle length, RIPTL 6.8–9.9 % SVL (vs. 5.5–7.7 % SVL); a shorter ratio of hindlimb-length, RTHIGH 48.6–56.9 % SVL, RTL 49.6–54.4 % %SVL (vs. 54.3–58.4 % SVL, 53.6–57.8 % %SVL, respectively) (see Tables 2 View TABLE 2 and 3 View TABLE 3 ).

On its appearance, Rhacophorus boeadii sp. nov. is most similar to R. monticola than to other Sulawesian congeners, but this new species can be distinguished from R. monticola by having the following combination of external characters, a larger body size, SVL 40.4–44.6 mm in males (vs. males 32.5–40.6 mm); snout sloped in lateral view, with the tip protruding (vs. the snout sloped without protrusion at the tip, Fig. 8A, C View FIGURE 8 ); web reaching second sub-articular tubercle on preaxial side of third finger (vs. reaches 1.25 sub-articular tubercles, Fig. 8Q, S View FIGURE 8 ); dorsal skin of males coarsely granular with white-tipped keratinized asperities (vs. smooth, Fig. 8I, K View FIGURE 8 ); cloaca with many tubercles (vs. absent, Fig. 8M, O View FIGURE 8 ); flank with white blotched pattern (vs. immaculate unpatterned, Fig. 8I, K View FIGURE 8 ); dark blotching on ventral surface of chin and chest, lateral side of forelimbs, and hind-limbs (vs. immaculate whitish; head length ratio relatively shorter, RHL 34.5–36.6 % SVL (vs. 34.6–40.1 % SVL); narrower head width ratio, RHW 27.6–33.7 % SVL (vs. 31.0-37.1 % SVL); a shorter ratio of inter-orbital distance, RIOD 10.5–12.5 % SVL (vs. 10.2–14.2 % SVL); a slightly shorter ratio of eye length, REL 13.4–17.1 % SVL (vs. 14.9–18.5 % SVL), a smaller ratio eye diameter, RED 12.5–14.8 % SVL (vs. 13.5–17.7 % SVL); a longer lower arm length ratio, RLAL 49.1–54.2 % SVL (vs. 45.4–53.3 % SVL); a larger inner palmar tubercle length ratio, RIPTL 6.8–9.9 % SVL (vs. 5.7–7.4 % SVL); a longer tibia length ratio, RTL 49.6–54.4 % SVL (vs. 46.9–51.9 % SVL); a slighty larger inner metatarsal tubercle length, RIMTL 3.0–4.6 % SVL (vs. 2.4–4.6 % SVL); darker webbing on the hand and foot (vs. yellowish or whitish).

Call Characteristic Comparison. Call characteristic of R. boeadii sp. nov. differs from R. edentulus by having only one type of call (vs. two types in R. edentulus : Kurniati, 2014); more pulses (2–8 pulses vs. 1–4 pulses: Kurniati, 2014); shorter duration of pulses (5-15 ms vs. 8–63 ms: Kurniati, 2014); and lower dominant frequency (1125–1500 Hz vs. 1031–2109 Hz: Kurniati, 2014).

Tadpole Comparison. Tadpole (stage 25) of Rhacophorus boeadii sp. nov. can be distinguished from R. georgii by having ovoid body contour (vs. slender elongated, Gillespie et al., 2007); short tail, TAL 61.5 % of TTL (vs. long, TAL 61.3–74.3 % TTL, Gillespie et al., 2007); tooth row formula 5(3–5)/3(1) (vs. 5(2–5)/3(1), Gillespie et al., 2007); and V-shaped at lower jaw sheath (vs. slightly V-shaped; Gillespie et al. 2007).

In tadpole morphology, van Kampen (1923) reported tadpole information that possibly corresponded to Rhacophorus monticola from Loka (topotype), but he did not provide sufficient information to determine its tadpole stage. The tadpole from Loka reportedly has the second row of upper and the third row of the lower lip narrowly interrupted ( van Kampen, 1923), whereas the second row of the upper lip is continued in the tadpole of the new species Unfortunately, we cannot translate the row formula made by van Kampen (1923) because of the absence of the definition of his tooth formula. In addition, Gillespie et al. (2004) reported that the tadpole of R. cf. monticola from the Buton island breeds and its tadpole can be found in streams whereas the new species breeds on the pond.

Range. Rhacophorus boeadii sp. nov. is currently only known from the montane primary forest above 1000 m a.s.l. in Mt. Katopasa and Mt. Gandang Dewata on the island of Sulawesi.

Natural History. Two specimens (MZB Amph 26641, 26642) from Mt. Gandang Dewata were collected on a tree branch, approximately 1.5–2 m above the ground. The trees were located 1–2 m from the edge of a rocky stream at the elevation of 1642 m a.s.l. The specimens from Gandang Dewata were collected in April, 2017. We detected no calls during that period. The specimens from Mt. Katopasa were collected from an elevation of 1471 m a.s.l., in swamp dominated by sedges, which was approximately 80 m in length X 20 m in width (~ 1600 m 2) and surrounded by pristine montane forest. In this place, we saw numerous foam nests of this species ( Fig. 9B, C View FIGURE 9 ), and many individuals in amplexus. The tadpole of new species is typically found in a lentic habitat (e.g., lake, pond). We found the following amphibians in sympatry with the new species on Mt. Gandang Dewata: Rhacophorus edentulus , Limnonectes grunniens (Latreille) , Chalcorana macrops (Boulenger) , Occidozyga semipalmata Smith , and Ingerophrynus celebensis (Günther) . On Mt. Katopasa, the only other frog found in the swamp was Polypedates iskandari Riyanto, Mumpuni and McGuire. We also observed the Sulawesi Black Rat Snake Ptyas dipsas (Schlegel) in this swamp on multiple occasions. Given that it was the breeding season of Rhacophorus boeadii sp. nov., it seems that this snake species is a potential predator of the frog.