Rhinella unapensis, Rojas & Peña & Ávila & Carvalho & Perez & Farias & Gordo & Hrbek, 2022

Rojas, Rommel R., Peña, Pedro Perez, Ávila, Robson W., Carvalho, Vinicius Tadeu De, Perez, Renata, Farias, Izeni Pires, Gordo, Marcelo & Hrbek, Tomas, 2022, Two new surprising species of leaf-litter toad of the Rhinella margaritifera species group (Anura: Bufonidae) from the Peruvian Amazon, Loreto-Peru, Zootaxa 5150 (4), pp. 487-515 : 504-510

Rhinella unapensis sp. nov.

Synonyms

Bufo typhonius (Rivera-Gonzales et al. 2003)

Bufo typhonius gr. margaritifera Ribeyro & Layche (2008)

Holotype. CRBIIAP-2125 adult male collected at Puerto Almendra (3° 49’ 58’’ S, 73° 22’ 28’’ W), Department of Loreto, Province of Maynas , District of San Juan , Nina-Rumi community, Peru by Rommel R. Rojas on December 7, 2017, at 10 h. ( Figure 7 A–F ).

Paratypes. CRBIIAP-2114, CRBIIAP-2115, CHUFC-A 9201 , CHUFC-A 9202 , adult females collected at Puerto Almendra , (3° 49’ 27’’ S, 73° 22’ 59’’ W), Department of Loreto, Province of Maynas , District of San Juan , Nina-Rumi community, Peru by Rommel R. Rojas Zamora. CRBIIAP-2116, CRBIIAP-2117, CRBIIAP-2123, CRBIIAP-2124, adult males collected at Puerto Almendra , (3° 49’ 52’’ S, 73° 22’ 29’’ W), Department of Loreto, Province of Maynas , District of San Juan , Nina-Rumi community, Peru by Rommel R. Rojas Zamora. CRBIIAP-2118, CRBIIAP-2119, CRBIIAP-2120, CRBIIAP-2121, CRBIIAP-2122, juveniles collected at Km 70.0 by the Iquitos-Nauta highway (04° 21’ 15’’ S, 73° 30’ 53’’ W) Department of Loreto, Province of Maynas , District of San Juan , Nuevo San Juan community, Peru by Rommel R. Rojas. MZUNAP-AN 509, MZUNAP-AN 540 adult males collected at Fundo UNAP km 31.5 by the Iquitos-Nauta highway (03º 56’ 36’’S, 72º 24’ 06’’W), Department of Loreto, Province of Maynas , District of San Juan , Iquitos-Nauta highway by Percy Mejia ( Figure 8 A–L ) .

Diagnosis. Rhinella unapensis sp. nov. is diagnosed by: (1) small-size (snout-vent length range 30.1–42.5 in adult males, 36.3–46.1 mm in adult females); (2) snout pointed in dorsal view, nearly acute in lateral view; (3) canthal and pre-orbital crests absent; (4) low supra-orbital, parietal and supra-tympanic crests; (5) small bony protrusion at the angle of jaws; (6) tympanum evident; (7) dorsolateral row of tubercles present; (8) parotoid glands small, elongate and evident; (9) skin on dorsum bearing a mixture of warts.

Holotype measurements (mm). SVL 36.0; HL 12.3; HW 11.85; IND 2.3; END 4.1; ED 3.2; UEW 3.4; IOD 4.0; POCH 1.0; POCL 3.1; HTD 2.1; VTD 1.8; PGL 4.6; HAL 10.4; FAL 7.6; THL 14.8.; TL 13.2; TAL 8.4; FL 10.4.

Comparison with other species. By the absence of canthal and pre-orbital crests Rhinella unapensis sp. nov. is promptly distinguished from R. alata , R. cristinae , R. exostosica , R. hoogmoedi , R. iserni , R. margaritifera , R. ocellata , R. roqueana , R. scitula , R. sebbeni , R. sclerocephala , and R. stanlaii . Rhinella unapensis sp. nov. It also differs from the Amazonian species cited above by (characteristics of other species in parenthesis): From R. alata by presence of bone protrusion at angle of jaw (absent), snout pointed in dorsal view, nearly acute in lateral view (sub acuminate in dorsal view, rounded to protruding in lateral view), palmar tubercle ovoid (oval). From R. cristinae by the acute snout in lateral view (rounded), tympanum distinct (indistinct), larger males, with 30.1–45.5 mm SVL (30.7–34.3 mm), smaller females, with 36.3–46.1 mm SVL (55.1 mm). From R. exostosica by being smaller in SVL (64.2 vs. 37.7 mm R. unapensis sp. nov.), palmar tubercle shape ovoid (tear-shaped), parotoid glands small and elongate (prominent), cephalic crest poorly developed (developed). From R. iserni by the presence of external tympanum (not distinguish), parotoid gland lacking lateral line of tubercles (presence), smaller SVL (35.4 mm in R. unapensis sp. nov. vs. 58.5 mm in adult males). From R. margaritifera by the small vertebral apophyses (protruding), low cranial crests (vs. well developed), snout nearly acute in lateral view (mucronate), smaller SVL (30.1–45.5 mm in adult males in R. unapensis sp. nov. vs. 58 mm in adult males). From R. roqueana by the small SVL (30.1– 45.5 in adult males of R. unapensis sp. nov. vs 70–79 mm in adult males of R. roqueana ), absence of protruding vertebral apophyses (present), tympanum evident (hidden), the snout nearly acute in lateral view (pointed). From R. sclerocephala by snout nearly acute in lateral view (truncate), by smaller SVL (35.4 mm in R. unapensis sp. nov. vs. 61.2 mm in adult males), absence or very small vertebral apophyses (hypertrophied). The new species can also be distinguished from the species of the Rhinella margaritifera group from outside the Amazonia as follows. From R. hoogmoedi by the absence of a rounded tubercle at the posterior corner of mouth (present); dorsolateral line of pointed tubercles not well marked (well-marked). From R. ocellata by the absence of dorsal ocelli colour pattern. From R. scitula by the parotoid gland small (larger); absence of bony knobs at the angle of jaws (present); absence of a line of spinulose tubercles on parotoid gland (present). From R. sebbeni by supratympanic crest poorly developed (well-developed), and snout pointed in dorsal view (mucronate). From R. stanlaii by the smaller SVL (35.44 mm in R. unapensis sp. nov. vs. 45.8 mm in adult males), small parotoid gland (paratoid gland developed).

In addition to the absence of canthal and pre-orbital crests, eight species of the Rhinella margaritifera group are similar to the new species for their low supra-orbital, parietal and supra-tympanic crests: R. acutirostris , R. castaneotica , R. dapsilis , R. lescurei , R. magnussoni , R. parecis , R. proboscidea and R. angeli .

The new species is distinguished from R. acutirostris by absence of tubercles on the lateral of parotoid gland (presence), the snout nearly acute in lateral view (pointed), and dorsolateral line of tubercles weak (marked dorsolateral line of tubercles). From R. castaneotica by the presence of a small bone protrusion at angle of jaw (absent), presence of external tympanum (not distinguish), the snout nearly acute in lateral view (pointed). From R. dapsilis by smaller SVL (30.1–45.5 in adult males, 36.3–46.1 in adult females in R. unapensis sp. nov. vs. 50–59 in males and 63–94 mm SVL in adult females of R. dapsilis , snout lacking a developed proboscis (present), granular skin (smooth) and by the dorsolateral line of tubercles weak (marked dorsolateral line of tubercles). From R. lescurei by the elongate parotoid gland (triangular parotoid gland), snout nearly acute in lateral view (pointed). From R. magnussoni by skin on dorsum bearing a mixture of warts (skin of dorsum with spicules), pointed snout (rounded), nostril not protuberant (nostril protuberant) and distinct tympanic membrane (barely distinct). From R. parecis by the snout nearly acute in lateral view (rounded), presence of bone protrusion at angle of jaw (absent), elongate and distinct parotoid glands (small and not well distinct). From R. proboscidea by dorsal skin texture granular (smooth), less protruding snout (snout distinctly prominent).

Finally, from R. angeli sp. nov. the new species is differentiated by the absence of a fleshy proboscis (present even in juveniles), presence of bone protrusion at angle of jaw (absent), snout profile nearly acute in lateral view (pointed), head as longer as wide (wider than long), postocular crest longer with 2.9–4.4mm (1.2–1.5mm) and lower 0.8–1.3mm (3.2–3.7mm), forearm length larger than hand length (equal) and thigh and tibia length almost equal (thigh longer than tibia). Both species are also geographically separated by the Ucayali and Amazon Rivers, with R. angeli sp. nov. distributed on the left bank and R. unapensis sp. nov. limited to the right bank.

Description of holotype. CRBIIAP-2125 adult male. Body robust. SVL 36.0 mm; head wider (12.3 mm) than longer (11.8 mm). Snout pointed in dorsal view, nearly acute in lateral view. Canthal crest not raised; supraorbital and postorbital crests not developed with low supratympanic crest. Small parotoid gland, not well developed, slightly triangular in dorsal view, expanding laterally. Lateral row of tubercles from posterior margin of parotoid gland to base of the leg. Small bony protrusion at the angle of jaws. Canthus rostralis concave; interorbital and internarial region flat, nostrils acute directed dorsolaterally. Eye to nostril distance longer than eye diameter, larger than internarial distance. Upper eyelid width about 91.7% of eye diameter. Tip of the snout without developed proboscis. Tympanum distinct, rounded; its horizontal diameter representing 95.5% of the vertical diameter and smaller than internarinal distance. Triangular corner of mouth, presence of bony knobs at the lower angle of jaws. Paratoid glands distinguished, elongate. Vocal slits absent; small choanae, ovoid, lateral, widely separated; tongue free. Dorsolateral line of small white pointed granules extends from the posterior border of the parotoid gland to the groin. Very small vertebral apophyses. Skin on dorsal and ventral surfaces highly granular. Presence of rounded granules in dorsal and ventral surfaces. Small tubercles covering lips, eyelids, interorbital and loreal region. Slender forearms, robust forelimbs, covered with small and scattered tubercles around the edges. Free fingers, with the tips slightly enlarged; length of fingers 2<4<1<3. Lateral fringes with small conical tubercles present on the fingers edges. Ovoid, large, smooth palmar tubercle; oval thenar tubercle, about one third of the palmar tubercle; subarticular and supranumerary tubercles present, rounded. Robust hindlimbs, thigh length larger than tibia length, thigh + tibia length approximately 77.9% of the SVL; foot length 74.3% of tibia length, tarsal length 80.9% of foot length. Inner metatarsal tubercle oval, two times larger than the outer metatarsal tubercle; subarticular and supernumerary tubercles present, small, round. Length of toes 1<2<3<5<4; toes half-webbed, webbing formula: I1-2 II 1-2 ½ III 1-3 IV 3-1V. Lateral fringes with small conical tubercles present on toes.

Color in life. Dark brown dorsal coloration. A light-brown vertebral line from the interorbital region to cloaca, surrounded by light brown spots. Small light brown spots scattered distributed at head, midbody and shanks. Dark brown bands on arms and legs and dark brown blotches on flanks and tympanic region. White-cream venter with pointed dark brown blotches on chest and belly. Loreal and tympanic region with dark brown blotches. Cream color throat; arms and legs white cream with dark brown points. Gold iris, with black reticulations ( Figure 9 A–H ).

Morphological variation. The type series includes 17 specimens (8 adult males, 4 adult females and 5 juveniles). Dorsal skin texture not variable between sexes, being covered with rounded tubercles in males and females. Sexual dimorphism is present ( Table 5 ). Presence of low cranial crests in both sexes, without differences between male and female, in juveniles the crest is indistinct. Dorsal coloration is variable, from dark brown to brown ( Figure 9 A–H ). There is presence of dark-brown spots in the head, neck, midbody and shanks region. Some individuals present a light brown vertebral line. Gular and chest region may present a brown coloration or cream coloration. Ventral coloration variable from almost immaculate cream to heavily pigmented with dark blotches or points.

Distribution and natural history. Rhinella unapensis sp. nov. is known from five localities from Loreto department, Peru, western Amazonia ( Figure 5 ). Fundo Zamora, Fundo UNAP, Allpahuayo Mishana National Reserve, the vicinity of Nauta and Puerto Almendra in the Nanay river basin. Its distribution is in the northwest of Iquitos (left bank of the Amazon, around the Nanay and Marañon Rivers), where it spans the length of the Iquitos-Nauta highway; further north, its distribution is poorly known but is possibly delimited by the Napo and Marañon Rivers. This species has been recorded from white sand forests, locally known as “ varillales ” (in Portuguese “ campinaranas ”), from around Iquitos city ( Figure 10 A ). They have been found in the leaf litter of primary and secondary forests, and occur between 103 to 135 m a.s.l. They are diurnal species. During night surveys, the species was seen resting in stems and leaves of low shrubs (~ 1.20 m) ( Figure 10 B–C ).

Colour in preservative. Similar to that in life. In 70% alcohol, the body coloration presents a slightly faded mainly in dark brown blotches ( Figure 8 ).

Etymology. The specific epithet refers to the Universidad Nacional de la Amazonia Peruana-UNAP in honor of the legacy of all professors who passed away due to COVID-19 and other diseases.

Tadpole. Unknown.

Vocalization. Unknown

Figures

FIGURE 5. Distribution map of the two new species described herein. Rhinella angeli sp. nov. Yellow color: 1) Nueva Esperanza; 2) Panguana; 3) Mircillo; 4) Sacacaca; 5) Cauchuyo; 6) Corrientes; 7) Taguado; 8) Sierra del Divisor National Reserve; 9) Matsés National Reserve. R. unapensis sp. nov. Red color: 1) Puerto Almendra; 2) Fundo UNAP; 3) Iquitos-Nauta Highway 70 km. Stars indicate the type locality.

FIGURE 7. Holotype of Rhinella unapensis sp. nov. (CRBIIAP-2125); A) dorsal view; B) ventral view; C) lateral view of head; D) dorsal view of head; E) ventral view of right hand; F) ventral view of right foot.

FIGURE 8. Type series and morphological variation in preserved specimens of Rhinella unapensis sp. nov. A–C= CRBIIAP- 2114 (adult female); D–F=MZUNAP-AN 540 (adult male); G–I= CRBIIAP-2115 (adult female); J–L= CRBIIAP-2123 (adult male).

FIGURE 9. Morphological variation of living specimens of Rhinella unapensis sp. nov. A–D= Puerto Almendra locality; E–H= Allpahuayo Mishana Natural Reserve.

FIGURE 10. A= Habitat of Rhinella unapensis sp. nov. B–C= R. unapensis sp. nov. resting in leaves and stems of low shrubs (~1.20 m).