Boana ventrimaculata, Caminer & Ron, 2020

BOANA VENTRIMACULATA SP. NOV.

( FIGS 7C, 11; TABLE 5)

Lsid: urn:lsid:zoobank.org:act:34C45CDE-5F97-4AE8-A655-E2C1DA6E9787

Holotype ( Figs 7C, 11): QCAZ 51241 View Materials (field no. SC37210), adult male from Ecuador, Provincia Orellana, Estación Científica Yasuní PUCE (0.673° S, 77.407° W), 245 m a.s.l., collected by Italo Tapia, Teresa Camacho, Francy Mora and Santiago R. Ron, on 1 June 2011. GoogleMaps

Paratopotypes: QCAZ 51236 View Materials , adult male, collected with the holotype ; QCAZ 17517 View Materials , juvenile, collected by O. Pérez and M. Bustamante on 17 February 2000 .

Paratypes: ECUADOR: PROVINCIA MORONA SANTIAGO: Pankints (2.9019° S, 77.894° W), 332 m, QCAZ 46429 View Materials , adult female, collected by J. Brito on 26 December 2010 GoogleMaps ; PROVINCIA NAPO: Huino (0.6449° S, 77.149° W), 273 m, QCAZ 30928 View Materials , adult male, collected by D. Alvarado and G. Buitrón on 3 February 2003 GoogleMaps ; Misahuallí (1.0343° S, 77.6685° W), 401 m, QCAZ 20000 View Materials , adult female, collected by F. Ayala and M. Díaz on 26 March 2002 GoogleMaps ; PROVINCIA SUCUMBÍOS: Río Aguarico, San Pablo (0.255° S, 76.426° W), 220 m, QCAZ 6314–15 View Materials , adult females, collected on 2 August 1994 GoogleMaps ; PROVINCIA PASTAZA: Campamento K 10, Campo Villano (1.476° S, 77.5347° W), 475 m, QCAZ 38772 View Materials , adult male, 39247, 56429, 56307, adult females, 38663, juvenile, collected by Y. Mera, D. Paucar, F. Ayala, E. Carrillo, G. Díaz, J. Brito and D. Velalcázar on 14 February 2008 and 18 November 2013 GoogleMaps ; Comunidad Tarangaro, Campo Villano (1.3951° S, 77.3838° W), 338–1035 m, QCAZ 39130 View Materials , 54233 View Materials , 54238 View Materials , adult males, 39137, adult female, collected by Y. Sagredo, A. Barahona, D. Paucar, G. Díaz, Y. Mera and F. Ayala on 23 August 2008 and 20 June 2012 GoogleMaps ; Juyuintza , 4.5 km SE (2.1132° S, 76.1646° W), 164 m, QCAZ 53533 View Materials , adult male, collected by M. Ortega and F. Timias on 26 June 2012 GoogleMaps ; Lorocachi (1.6386° S, 75.9711° W), 207 m, QCAZ 56114 View Materials , adult male, collected by S. R. Ron, D. Paucar, F. Ayala, D. Velalcázar, M. J. Navarrete, G. Galarza, J. Pinto, V. Chasiluisa, S. Arroyo and D. Zurita on 23 June 2013 GoogleMaps ; PROVINCIA ORELLANA: Nuevo Rocafuerte, Río Napo (0.9165° S, 75.423° W), 194 m, QCAZ 44845–46 View Materials , adult males, collected by S. R. Ron, E. Toral and I. Tapia on 12 July 2009 GoogleMaps ; Parque Sumaco Balsayacu (0.3724° S, 77.3411° W), 600 m, QCAZ 23059 View Materials , adult male, collected by P. Salvador on 16 January 2002 GoogleMaps ; Estación de Biodiversidad Tiputini USFQ (0.633° S, 76.1473° W), 231 m, QCAZ 20398 View Materials , adult male, collected by M. D. Proaño on 2 July 2002 GoogleMaps ; Estación Científica Yasuní PUCE, km 8 on the road Tivacuno (0.6815° S, 76.3897° W), 251 m, QCAZ 18280 View Materials , adult female, collected by D. Paucar on 20 December 2001 GoogleMaps ; Yasuní (0.6771° S, 76.4011° W), 230 m, QCAZ 13962 View Materials , adult male, 30271, adult female, collected by D. Prado on 18 November 1999 GoogleMaps ; Yasuní, Apaika (0.8111° S, 76.704° W), 200 m, QCAZ 27788–89 View Materials , adult males, collected by F. Nogales on 11 October 2000 GoogleMaps ; Parque Nacional Yasuní, km 38 on the road Pompeya Sur-Iro (0.6535° S, 76.4535° W), 238 m, QCAZ 17251 View Materials , adult male, collected by S. de la Torre on 25 February 1994 GoogleMaps ; Parque Nacional Yasuní, km 45 on the road Pompeya Sur-Iro (0.6940° S, 76.4562° W), 247 m, QCAZ 8181 View Materials , adult female, collected by M. Read on 29 January 1995 GoogleMaps ; km 74 on the road Pompeya Sur-Iro (0.8358° S, 76.3533° W), 257 m, QCAZ 5105 View Materials , adult female, collected by S. de la Torre on 20 May 1994 GoogleMaps ; Parque Nacional Yasuní, Ginta-Bloque 16 (0.9981° S, 76.1963° W), 243 m, QCAZ 20465 View Materials , adult male, collected by M. Díaz on 27 January 2001 GoogleMaps ; Parque Nacional Yasuní, on the road Pompeya Sur-Iro km 21 (0.6504° S, 76.5201° W), 306 m, QCAZ 13301 View Materials , adult female, collected by F. Sornoza on 21 August 1996 GoogleMaps ; km 38 on the road Pompeya Sur-Iro (0.6539° S, 76.4518° W), 230 m, QCAZ 49129 View Materials , adult female, collected by M. Read on 11 January 1996 GoogleMaps ; km 107 on the road Pompeya Sur-Iro (0.9811° S, 76.2476° W), 249 m, QCAZ 6821 View Materials , 49233 View Materials , adult males, 8325, 30972, adult females, collected by S. Harris and M. Read on 12 November 1994 and 4 November 1996 GoogleMaps .

Common names : Proposed standard English name: Yasuní treefrog. Proposed standard Spanish name: rana arbórea del Yasuní.

Diagnosis ( Figs 7C, 11): Boana ventrimaculata is characterized by: (1) mean SVL 52.7 mm in males (range 44.5–60.7; n = 20), 81.6 mm in females (range 72.9–90.5; n = 17; Table 5); (2) thighs long (TL/SVL 0.45–0.56); (3) dorsal skin finely granular; (4) dorsum brown, dark brown, cream or dull tan usually with an X- shaped mark on scapular region; (5) flanks grey with white speckles, and hidden surfaces of thighs grey with black vertical bars; (6) areolate skin on the posterior surface of throat, belly and ventral surfaces of thighs; (7) venter creamy white to yellowish white, plain or with brown blotches; (8) in life, webbing brown or orange; (9) palpebrum reticulated; (10) nuptial excrescences present in breeding males; (11) projecting prepollices absent in both sexes; (12) tympanum large with distinct tympanic ring; (13) small, triangular calcar on heel, often with a cream spot; (14) advertisement call with one note; (15) 11 to 16 pulses per note; and (16) call dominant frequency varying from 475 to 685 Hz.

Comparisons with other species: Boana ventrimaculata differs from B. geographica , B. appendiculata and B. nigra by having a speckled pattern or blotches on the flanks (black flanks or dark vertical bars or stripes in the three species) and brown blotches on the ventral surfaces (immaculate or spotted with dark brown in the three species). Boana ventrimaculata is larger (male mean SVL = 52.72 mm; female mean SVL = 81.62 mm) than B. diabolica (male mean SVL = 43.50 mm, female mean SVL = 56.30 mm; Fouquet et al., 2016), B. geographica (male mean SVL = 43.00 mm, female mean SVL = 48.60 mm; Fouquet et al., 2016), B. appendiculata (t = 7.16, d.f. = 31.9, P <0.001) and B. nigra (t = 9.61, d.f. = 24.9, P <0.001) (Table 5). Among species of the B. geographica – B. semilineata species complex, B. ventrimaculata is morphologically more similar to B. diabolica and B. hutchinsi . However, it can be distinguished by having a speckled pattern on the hidden surfaces of thighs and brown to orange webbing in life (hidden surfaces of thighs and webbing are immaculate red in B. diabolica ; black in B. hutchinsi ; Pyburn & Hall, 1984; Fouquet et al., 2016). Boana ventrimaculata can be further distinguished from B. hutchinsi by having a brown dorsum with black flecks in recently metamorphosed individuals (lavender-grey in B. hutchinsi ), and a shorter duration and lower number of notes in the advertisement call (one groan-like note with a mean call duration of 0.24 s in B. ventrimaculata ; four to six chuckle-like notes with a mean call duration of 0.68 s in B. hutchinsi ; Pyburn & Hall, 1984). Boana hutchinsi has not been included in molecular phylogenies and, therefore, current diagnosis are based exclusively on morphological and bioacoustic characters.

Specimens of B. ventrimaculata can be easily confused with B. semilineata due to their similar colour pattern (brown webbing, black flanks with white speckles and brown spots on the abdomen; Fouquet et al., 2016; Peloso etal.,2018), butthesespeciescanbeclearlydistinguished by having markedly differentiated advertisement calls (one note with a mean duration of 0.24 s, and mean dominant frequency of 561 Hz in B. ventrimaculata vs. one to three notes with a mean duration per note of 0.04 s, and mean dominant frequency of 1240 Hz in B. semilineata ). The type localities of both species are separated by ~ 4500 km making it extremely unlikely that they represent the same species.

Boana ventrimaculata is easily distinguished from B. boans , B. icamiaba , B. pombali and B. wavrini by its prepollex not modified into a projecting spine and by the presence of pigmented nuptial excrescences. Boana boans further differs from B. ventrimaculata in having diffuse vertical bars on the flanks (speckled pattern in B. ventrimaculata ) and by its fully webbed hands (webbing extends to about the middle of the outer finger in B. ventrimaculata ).

Description of the holotype: Adult male, 57.6 mm SVL, foot length 21.5 mm, head length 12.4 mm, head width 19.3 mm, eye diameter 6.2 mm, tympanum diameter 4.8 mm, tibia length 27.8 mm, femur length 26.4 mm, calcar length 2.3 mm, arm length 9.9 mm, eye–nostril distance 7.1 mm, head wider than long and wider than body; snout truncate in lateral view, subacuminate in dorsal view; distance from nostril to eye larger than diameter of eye; canthus rostralis rounded; loreal region concave; internarial region subtly depressed; nostrils not protuberant, directed laterally; interorbital area slightly convex; eye large, protuberant; lower eyelid finely reticulated; diameter of eye 1.3 times diameter of tympanic annulus; supratympanic fold inconspicuous; tympanic membrane roundish, slightly longer than high; tympanic annulus evident, rounded, separated from eye by c. 0.4 times its diameter. Arm slender, axillary membrane absent; relative length of fingers I <II <IV <III; finger discs broadly expanded, round, as wide as long; subarticular tubercles prominent, round to ovoid, single; supernumerary tubercles absent; palmar tubercle inconspicuous; large and rugose dark P-shaped nuptial pad on dorsal surface of finger I; prepollex not modified into a projecting spine; webbing formula of fingers I basal II1—2 – III2 – —1 + IV. Toes bearing discs broadly expanded, rounded and slightly smaller than those of fingers; relative length of toes I <II <V <III <IV; inner metatarsal tubercle large, elliptical; outer metatarsal tubercle absent; subarticular tubercles single, round, large and protuberant; supernumerary tubercles small, round; webbing formula of toes I1—1II1 – —1III1—1IV1— 1 – V. Vocal sac single and subgular. Skin on dorsum, head and dorsal surfaces of limbs finely granular; throat smooth anteriorly without mental gland; posterior surface of throat, belly and ventral surfaces of thighs areolate, those of shanks smooth. Cloacal opening directed posteriorly at upper level of thighs, round tubercles below and on the sides of vent. Tongue slightly cordiform, widely attached to mouth floor; odontophores situated parallel to choanae, in two oblique series closely set, each bearing 19–21 vomerine teeth; choanae trapezoidal, oblique.

Colour of holotype in preservative ( Fig. 11): Dorsum brown with a dark brown X- shaped mark on the scapular region and a dark brown transversal band on the sacrum; dark brown triangle with its base in the interorbital area and its apex between the nostrils; dark brown transversal bands on the dorsal surfaces of the limbs; flanks grey with dark brown blotches; hidden surfaces of the thighs grey with brown vertical bars; venter cream with brown rounded blotches on the belly; discs and webbing grey.

Colour of holotype in life ( Fig. 7C): Dorsum background brown with dark brown marks; dark brown transversal bands on the dorsal surface of limbs; flanks grey with brown blotches; hidden surfaces of thighs and shanks grey with brown vertical bars; venter and ventral surfaces of thighs yellowish with brown rounded blotches on the belly; throat cream; webbing orange; iris brown; bones green.

Etymology: The specific name is derived from the Latin words ventriculus = belly, and macula = spot or stain, in reference to the brown blotches on the chest and belly of these frogs.

Variation in preservative: Morphometric data for adult specimens are summarized in Table 5. Variation in dorsal and ventral coloration of preserved specimens is shown in Fig. 11. Sexual dimorphism is observed in SVL, with 44.5–60.7 mm (52.7 ± 4.6 mm, N = 20) in males and 72.9–90.5 mm (81.6 ± 5.4 mm, N = 17) in females. Females are significantly larger than males (t = –17.39, d.f. = 31.5, P <0.001).

Head shape varies between subacuminate and rounded in dorsal view; in lateral view it varies between truncate and short, rounded. The head is slightly wider than the body, but in some cases equal (e.g. QCAZ 39137). Breeding males have keratinized nuptial excrescences on the inner surfaces of the thumbs. Calcar size ranges from inconspicuous (e.g. QCAZ 30928) to prominent (e.g. QCAZ 51241). Webbing on the hand varies slightly among specimens: fingers I basal II (1 –– 1 +)—(2 –– 2 +) III (1 + –2 –)—(1–1½) IV. Variation of webbing between toes is I (1 –– 1 +)—(1–1 +) II (1–1 –)—(1–2) III (1 –– 1 +)—(1–2 –) IV (1–2 –)—(1 –– 1 +) V. Vomerine teeth (N = 10): 14–21 (right = 16.9) and 12–22 (left = 18).

Variation in dorsal coloration of preserved specimens is extensive. Dorsal coloration varies from brown (e.g. QCAZ 30928) to dark brown (e.g. QCAZ 56307), cream (e.g. QCAZ 49233) or dull tan (e.g. QCAZ 39137) with irregular faintly or well-defined dark brown marks in diverse patterns, but most frequently consist of an X- shaped mark on the scapular region (e.g. QCAZ 13962). Individuals usually have a dark brown transversal band (e.g. QCAZ 39247) or two narrower transversal bars usually interconnected on the sacral region (e.g. QCAZ 13962). In some specimens there are scattered minute black flecks and white rounded spots on the dorsal surfaces (e.g. QCAZ 38772, 56114). Individuals may display asymmetrically distributed large cream blotches on the dorsum (e.g. QCAZ 44845). The coloration of flanks is grey with white speckles or sometimes with brown blotches. Vertical bars are present on the hidden surfaces of the thighs and sometimes on the shanks (e.g. QCAZ 39137). Dark transversal bands are present on the dorsal surfaces of the limbs (one or two on the upper arm and forearm and three to five on the thigh, shank and foot). The heels have usually the same colour as the rest of the body (e.g. QCAZ 8181, 13962), but in some individuals, heels are cream contrasting with the background dorsal coloration (e.g. QCAZ 49233).

Ventral surfaces of preserved specimens vary from creamy white (e.g. QCAZ 30928) to yellowish white (e.g. QCAZ 8181) with a belly usually yellowish. Lips, throat, chest, belly and ventral surfaces of the limbs usually with brown blotches (e.g. QCAZ 39247, 49233, 56114). Coloration of webbing and discs vary from yellowish white to brown or cream. Coloration of bones is white or green.

Coloration in life ( Fig. 7C): Dorsal surfaces vary from brown (e.g. QCAZ 56114) to dark brown (e.g. QCAZ 56307) or reddish brown (e.g. QCAZ 38772); brown transversal bands on dorsal surfaces of limbs; brown marks and white or yellow blotches on dorsum (e.g. QCAZ 56114, 56429); in some individuals, there are scattered minute black dots on dorsal surfaces (e.g. QCAZ 39130); flanks are grey or bluish with white speckles; hidden surfaces of thighs and shanks are bluish with dark vertical bars; venter and ventral surfaces of thighs vary from yellowish to cream white usually with brown blotches on the belly (e.g. QCAZ 39130, 56429); throat cream white or yellowish with or without brown blotches; webbings vary from brown to orange; fingers and toes dorsally vary from brown to grey; iris copper (e.g. QCAZ 51236); palpebrum finely reticulated with golden yellow.

In recently metamorphosed individuals, flanks, hidden surfaces of thighs and webbing are black; venter is grey; dorsal surfaces of the limbs are dark brown; dorsum is brown with black flecks over the entire surface. ( Fig. 8C).

Vocalization: One male ( QCAZ 49233 View Materials ) was recorded at Yasuní, on the road Pompeya Sur-Iro, km 108 ( Provincia Orellana) by Morley Read on 4 November 1996 at 20:00 h. The call ( Fig. 9G, H; Table 2) consists of one groan-like note with a mean duration of 0.24 s and dominant frequency of 561.4 Hz. Other call parameters are shown in Table 2. The individual was perched on vegetation 1 m above a stream .

Distribution and ecology: Boana ventrimaculata inhabits the Amazon basin of Ecuador (provinces of Morona Santiago, Napo, Orellana, Pastaza and Sucumbíos) and Brazil (Estado do Amazonas) ( Fig. 6). Localities with known elevation range vary between 64 and 1035 m of elevation. Among localities with known elevation, Comunidad Tarangaro (1035 m) is the highest and Rio Içá (64 m) is the lowest. Most specimens of B. ventrimaculata were found in terra firme forest and semi-flooded forests. Frogs have been found at night in primary and secondary forest, perching on vegetation 20 to 500 cm above the ground, near streams or along trails away from water bodies.

Vegetation types for Ecuadorian localities are: (1) Amazonian evergreen foothill forest, characterized by a mixture of Amazonian and Andean vegetation with a canopy of 30 m; (2) Amazonian lowland evergreen forest, characterized by high plant alpha-diversity and a canopy height of 30 m with emergent trees that reach 40 m; (3) lowland floodplain forest of white-waters, characterized by periodical flooding with white-waters from large rivers, with the vegetation reaching 35 m in height and several horizontal strata of vegetation; and (4) lowland forest of Mauritia flexuosa palms and black-waters characterized by a canopy height of 30 m with dense understory ( Sierra et al., 1999). Localities in Brazil fall within the Purus Varzea vegetation type (according to the World Wildlife Fund, 2017 classification scheme; available at http://www.eoearth.org/view/article/151948).