**Tadpole:** Not described.

**Distribution** (Figure 116): *Hyalinobatrachium munozorum* is known from localities in the Amazonian lowlands and Andean foothills of Colombia, Ecuador, Peru, and Bolivia at elevations below 980 m ([17,22,27,134,232], this work). In Ecuador, this species has been recorded from localities below 300 m; although, there is one juvenile (identification unconfirmed), found at 920 m (Specimens examined). In Ecuador, the potential distribution of the species is 101,986 km2.

**Figure 116.** Distribution of *Hyalinobatrachium munozorum* in Ecuador (yellow dots).

**Conservation status:** Globally, *Hyalinobatrachium munozorum* is listed as *Least Concern* by the IUCN [234]. Although *H*. *munozorum* is rare in collections, we presume that this is a consequence of inadequate sampling at the canopy level [166]. The distribution of the species is large and lacks immediate threats; thus, the *Least Concern* conservation status is justified.

**Evolutionary relationships** (Figure 101): *H*. *mondolfii* is the closest relative of *H*. *munozorum*.

**Taxonomic Remarks:** Lynch and Duellman [22] used the terms "heart visible" and "heart not visible" to illustrate the condition of the ventral parietal peritoneum; species that have a transparent (=clear) peritoneum were considered as having a "heart visible", whereas species with a white parietal peritoneum had a "heart not visible". Ruiz-Carranza and Lynch [27] discussed the character states of the pericardium; they applied the term "heart visible" for species that have a transparent parietal peritoneum as well as a transparent pericardium (red heart visible in life). In the same work, Ruiz-Carranza and Lynch [27] described *H*. *ruedai*, which was diagnosed by having a white pericardium; *H. ruedai* was compared with congenerics with a white heart, a list that did not include *H*. *munozorum*. We assume that Ruiz-Carranza and Lynch [27] interpreted the condition of "heart visible" for *H*. *munozorum* as equivalent to a visible red heart. As mentioned above, the type series of *H*. *munozorum* and *H*. *ruedai* have a white heart. The only other characteristic that could separate *H*. *ruedai* from *H*. *munozorum* is the hand webbing; however, the range observed in *H*. *ruedai* falls within the variation of *H*. *munozorum*. Therefore, herein we place *Hyalinobatrachium ruedai* Ruiz-Carranza and Lynch, 1998 [27], in the synonymy of *Centrolenella munozorum* Lynch and Duellman, 1973 [22].

**Specimens examined:** *H. munozorum:* Ecuador: *Provincia Sucumbíos:* Santa Cecilia (00◦03- N, 76◦58- W; 340 m), KU 118054 (holotype), 105251, 123225, 150620 (paratypes), 152488–89, 155493–96, 175504. *Provincia Orellana:* Río Yasuní (00◦51- S, 76◦23- W; ca. 250 m), KU 175215; Tiputini Biodiversity Station (00◦37- S, 76◦10- W; 190–270 m), DFCH-D105. *Provincia Zamora Chinchipe:* Shaime (4◦20- S, 78◦40- W; ca. 920 m), QCAZ 31056 (identification not certain). *Provincia Napo*: Tena (00◦59- S, 77◦49- W; 500 m), DFCH-USFQ 0735. *Provincia Pastaza*: Río Manderoyacu, EPN 6427; km 6 vía San Ramón-El Triunfo (1.355S, 77.86456), QCAZ 33261. Colombia: *Departamento Caquetá*: Municipio de Miraflores, Parque Nacional Natural Chiribiquete, 530 m, ICN 40409–11 (type series of *H*. *ruedai*), IND-AN 5448-52. Peru: *Departamento de Huanuco:* Finca Panguana, Río Llullapichis, 4–5 km upstream from Río Pachitea (9◦36- S, 74◦55- W; 200 m), KU 154749, 172167–69; *Departamento de Cuzco:* 40 km E Quince Mil on road to Puerto Maldonado, above Río Marcapata (13◦09- S, 71◦25- W), KU 197028–29.

*Hyalinobatrachium pellucidum* (Lynch and Duellman, 1973 [22]; Figures 117–120).

*Centrolenella pellucida* Lynch and Duellman, 1973 [22]. Holotype: KU 143298.

Type locality: "Río Azuela, 1740 m, Quito–Lago Agrio road, Provincia Napo (Sucumbíos), Ecuador."

*Hyalinobatrachium pellucidum*—Ruiz-Carranza and Lynch, 1991 [6].

*Hyalinobatrachium lemur* Duellman and Schulte, 1993. Holotype: KU 211768. Type locality: "west slope of Abra Tangarana, 7 km (by road) northeast of San Juan de Pacaysapa (06◦12- S, 76◦44- W, 1080 m), Provincia Lamas, Departamento San Martín, Perú". Synonymy by Castroviejo-Fisher, Padial, Chaparro, Aguayo, and De la Riva, 2009 [231].

**Common names:** English: Andean Glassfrog. Spanish: Rana de Cristal Andina. **Etymology:** The specific name *pellucidum* is derived from the Latin word *pellucidus* (clear, transparent) and refers to the transparent parietal peritoneum of this centrolenid frog [22].

**Identification:** *Hyalinobatrachium pellucidum* is distinguishable from most glassfrogs by having a completely transparent ventral parietal peritoneum, a white liver, and transparent pericardium (in life, red heart visible ventrally; Figure 117). On the Amazonian slopes of the Andes and Amazon basin, the only other species with a visible red heart in life is *H*. *iaspidiense*, which differs from *H*. *pellucidum* by having large lime green blotches and small black spots on the dorsum (both absent in *H*. *pellucidum*).

**Figure 117.** *Hyalinobatrachium pellucidum* in life. (**Left and center**): Male from Río Napinaza, Morona Santiago province, Ecuador, QCAZ 42000. (**Right**): Male from Miazi Alto, Zamora Chinchipe province, 1250 m, QCAZ 41648. Photos by Luis A. Coloma.

**Diagnosis:** (1) Vomerine teeth absent; (2) snout truncated in dorsal aspect and profile (Figure 118); (3) tympanum partially hidden under skin, its diameter about 30% of eye diameter; supratympanic fold low; (4) dorsal skin shagreen; (5) ventral skin texture areolate; lacking pair of enlarged subcloacal warts; (6) ventral parietal peritoneum transparent (condition P0); pericardium transparent; white peritoneum covering intestines and stomach; transparent peritoneum on urinary bladder (condition V6); (7) liver bulbous, hepatic peritoneum white (condition H2); (8) humeral spines absent; (9) webbing absent between Fingers I and II, extensive between outer fingers (Figure 118); webbing formula II 11/2–3<sup>+</sup> III 2<sup>+</sup>—(2−–2) IV; (10) webbing between toes extensive; webbing formula on foot I 1—11/<sup>2</sup> II 1<sup>+</sup>—2− III 1<sup>+</sup>—2<sup>+</sup> IV 2—1 V; (11) ulnar and tarsal folds present, usually white (but see Variation); (12) concealed prepollex; nuptial pad type unknown; (13) Finger I slightly longer than Finger II (Finger II about 95% of Finger I); (14) disc of Finger III width about 50% of eye diameter; (15) in life, dorsum pale green with diffuse yellow spots; venter transparent, exposing the red heart (Figure 117); color of bones white; (16) in preservative, dorsum creamy white with minute purple flecks visible under magnification; (17) iris pale silvery bronze in life; (18) dorsal surfaces of fingers and toes lacking melanophores; (19) each has a single, tonal note with a duration of 98–140 (mean = 128, SD = 8.7) ms; dominant frequency is at 5599–5857 (mean = 5690, SD = 58) Hz; (20) fighting behavior unknown; (21) egg clutches placed on the underside of leaves; maternal care absent; prolonged parental care provided by males; (22) tadpoles undescribed; (23) minute body size; in males, SVL 20.4–21.4 mm; in one female SVL 21.6 mm.

**Figure 118.** *Hyalinobatrachium pellucidum*, holotype, KU 143298. (**A**) Head in lateral view. (**B**) Head in dorsal view. (**C**) Hand in ventral view. Illustrations by Juan M. Guayasamin.

**Color in life** (Figure 117): Dorsum pale green with diffuse yellow spots; venter and hidden surfaces of limbs lacking pigment; fingers and toes yellow; parietal peritoneum clear; red heart visible; bones white; iris pale silvery bronze [22].

**Color in ethanol:** Dorsum creamy white with minute purple flecks and small white granules visible under magnification; digestive tract and liver covered by white peritonea; pericardium lacking iridophores; ulnar and tarsal folds white.

**Variation:** Castroviejo-Fisher et al. [231] reported the following variation: The holotype of *H*. *pellucidum* has marked and enameled ulnar, tarsal, and cloacal folds, while specimens previously identified as *H*. *lemur* (a synonym of *H*. *pellucidum*) only show weak and non-enameled folds. The variation is interpreted as being the product of preservation artifacts and intraspecific variation. Two additional specimens from the same locality and near the type locality of *H*. *lemur* (~45 Km straight line) show intermediate states regarding ulnar, tarsal, and cloacal folds. The specimen KU 217297 has an enameled but weak ulnar fold, a weak but non-enameled tarsal fold, and an enameled and weak cloacal fold; KU 217295 has an enameled and marked ulnar fold, an enameled but weak tarsal fold, and an enameled and marked cloacal fold. A specimen (MHNCP 4880) collected in Cusco, Peru, and assigned to *H*. *pellucidum*, has very weak and barely enameled ulnar, tarsal, and cloacal folds.

**Biology and ecology:** The holotype of *Hyalinobatrachium pellucidum* was found on the leaf of an herb over a small stream at night. The following species were in the same stream and in other small streams nearby: *Nymphargus megacheirus*, *N*. *anomalus*, *N*. *siren*, *Centrolene pipilata*, *Hyloscirtus phyllognathus* [22]. Short-term maternal care is absent; males provide prolonged parental care [25].

**Call** (Figure 119). We analyzed 36 notes from one individual (USNM 286708), recorded at the type locality of the species, Río Azuela, 1740 m, Napo province, Ecuador, by Roy McDiarmid. The advertisement call is relatively short which has a single note per call (i.e., call = note). Notes are moderate in duration and the note duration is 98–140 (mean = 128, SD = 8.7) ms. Notes are tonal and do not show any clear amplitude peaks. The dominant frequency is 5599–5857 (mean = 5690, SD = 58) Hz and is contained within the fundamental frequency. The fundamental frequency has a lower limit of 5163–5685 (mean = 5381, SD = 678) Hz and a higher limit of 5685–5943 (mean = 5778, SD = 56) Hz.

**Figure 119.** Call of *Hyalinobatrachium pellucidum* recorded at Río Azuela, 1740 m, Napo province, Ecuador, recorded by Roy McDiarmid (USNM 286708).

**Tadpole:** Not described.

**Distribution** (Figure 120): *Hyalinobatrachium pellucidum* is known from a few records in the lower montane rainforest on the Amazonian Andean slopes of Ecuador and Peru, at elevations between 1000–1740 m ([22,231], this work). In Ecuador, *Hyalinobatrachium pellucidum* inhabits the Eastern Foothill Forest and Eastern Montane Forest ecoregions, and it is known from localities between 1013 and 1740 m; these localities are Río Azuela, Río Reventador, km 6.6 on the Limón–Macas road, and Cordillera del Cóndor (Specimens Examined).

**Figure 120.** Distribution of *Hyalinobatrachium pellucidum* in Ecuador (yellow dots).

**Conservation status:** Globally, *Hyalinobatrachium pellucidum* is listed as *Near Threatened* by the IUCN [235]. In Ecuador, the species is severely fragmented because of agriculture, pasture lands, and mining. Thus, we sugges<sup>t</sup> that, locally, it should be placed in the *Vulnerable* category, following IUCN criteria b1, B2a, B2biii.

**Evolutionary relationships** (Figure 101): *Hyalinobatrachium pellucidum* is sister to *H*. *yaku*.

**Specimens examined:** *Hyalinobatrachium pellucidum:* Ecuador: *Provincia de Sucumbíos:* Río Azuela (0.1167 S, 77.6167 W; 1740 m), Quito–Lago Agrio road; KU 164691 (holotype), USNM 286708–10; Río Reventador, USNM 286711–12. *Provincia de Morona Santiago:* km 6.6 on the Limón-Macas road (ca. 2.92816 S, 78.344 W; 1013 m), QCAZ 29438. *Provincia de Zamora Chinchipe:* Cordillera del Cóndor, Miazi Alto (4.25044 S, 78.61356 W; 1282 m), QCAZ 41560–61.

*Hyalinobatrachium esmeralda:* Colombia: Departamento de Boyacá, Municipio de Pajarito, Inspección Policía Corinto, finca 'El Descanso', quebrada 'La Limonita', 1600–1650 m, ICN 9592–94, 9596, 9602–03 (type series of *H*. *esmeralda*).

## *Hyalinobatrachium valerioi* (Dunn, 1931 [236]; Figures 121–123).

*Centrolene valerioi* Dunn, 1931 [236]. Holotype: MCZ 16003. Typelocality:"LaPalma,CostaRica,4500feet".

 *Cochranella valerioi*—Taylor, 1951.

*Cochranella reticulata*—Taylor, 1958 [201]. Holotype: KU 32922. Type locality: "near bridge across Río Reventazón at the Inter-American Institute of Agriculture, Turrialba, Cartago Province, CostaRica".PlacedinStarrettandSavage,1973[209].

 synonymy by *Centrolenellavalerioi*—Starrett andSavage,1973[209].

*Hyalinobatrachiumvalerioi*—Ruiz-CarranzaandLynch,1991[6].

**Common names:** English: Reticulated glassfrog [237], Valerio's glassfrog. Spanish: Rana de Cristal Reticulada, Rana de Cristal de Valerio.

**Etymology:** The specific name *valerioi* is a patronym for Manuel Valerio, who, with Emmett R. Dunn, discovered the species in the field.

**Identification:** Ecuadorian population tentatively assigned to *Hyalinobatrachium valerioi* can be distinguished from all other glassfrogs by its green dorsum with numerous large yellowish–green spots (Figure 121), transparent ventral parietal peritoneum, and most visceral peritonea covered by iridophores. The pericardium varies from white to mostly transparent (red in life). Among Ecuadorian centrolenid, only *H*. *aureoguttatum* is similar, but differs by having large yellow to golden dorsal spots (Figure 102), which are produced by the interaction of xanthophores (yellow) and iridophores (white); the spots in *H*. *valerioi* are structurally different since they lack iridophores.

**Diagnosis:** (1) Vomerine teeth absent; (2) snout truncated in dorsal view, truncated to protruding in lateral view; (3) tympanum with a dorsolateral orientation, of moderate size (tympanum diameter 30%–43% of eye diameter); tympanic membrane evident; only lower border of tympanic annulus visible; (4) dorsal skin finely shagreen; (5) ventral skin granular; no cloacal ornamentation; (6) parietal peritoneum transparent (condition P0), iridophores covering all visceral peritonea; pericardium variable, from white to mostly translucent (condition V5–V6); (7) liver bulbous, covered by white peritoneum (condition H2); (8) humeral spine absent; (9) webbing between Fingers I and II reduced, moderate between Fingers II and III, expanded between outer fingers, webbing formula: I (2<sup>+</sup>–21/3)—2 II (1–1<sup>+</sup>)—(3−–31/3) III (1<sup>1</sup>/2–22/3)—(1<sup>+</sup>–2−) IV; (10) webbing on feet: I (1–1<sup>1</sup>/2)—(2–2+) II (1–1<sup>2</sup>/3)—(2–21/4) III (1−–11/3)—(2<sup>+</sup>–21/3) IV (2–2<sup>1</sup>/2)—(1–1+) V; (11) ulnar and tarsal fold absent; (12) nuptial excrescences Type V in adult males; concealed prepollex; (13) first finger slightly longer than second; (14) eye diameter larger than width of disc on Finger III (disc of Finger III 32%–36% of eye diameter); (15) in life, dorsal surfaces yellowish green with green reticulum (or green with numerous yellowish–green spots); ventral parietal peritoneum transparent; bones white; (16) in preservative, dorsal surfaces cream with dark melanophores; (17) in life, iris golden with dark pigmentation scattered throughout, especially around the pupil; (18) melanophores absent from fingers and toes, except for few on Toes IV and V; (19) males usually call from underside of leaves, but sometimes they call from the upper leaf surface; call is a short *seet*, with a duration of 200–250 milliseconds, and a modulated frequency; (20) amplexus-like fighting behavior; (21) egg clutches laid on underside of leaves; nocturnal and diurnal parental care by males; maternal care absent; (22) tadpole with ventral mouth, spiracle posterior and mid-lateral; oral disc complete, moderate, with single row of marginal papillae laterally and ventrally, large dorsal gap; tooth row formula 2(2)/3, A-2 with large gap above mouth; (23) minute body size; SVL in adult males 18.1–24.4 mm (*n* = 23), in adult females 20.2–25.1 mm (*n* = 7).

**Figure 121.** *Hyalinobatrachium valerioi* in life. (**Top row**): Male from Reserva de Biodiversidad Mashpi, 1080 m, Ecuador; photos by Lucas Bustamante/Tropical Herping. (**Bottom row**): Male guarding eggs, Selva Verde Lodge, Costa Rica; photo by Carlos Martínez. Note differences in coloration.

**Color in life** (Figure 121): According to Kubicki [24], dorsum yellowish green with green reticulation. Transparent venter; pericardium varies from white to almost transparent; white liver and digestive tract. Iris golden with dark pigmentation scattered throughout, especially surrounding pupil; several individuals with dark pigmentation restricted to lateral regions of pupil. Bones white.

**Color in ethanol:** Cream dorsum with dark melanophores in the places that where green in life. Venter translucent cream. Parietal peritoneum completely transparent, all visceral peritonea covered by white lining. Pericardium polymorphic and white or translucent.

**Biology and ecology:** The following information was obtained from Savage [42], McDiarmid and Adler [238], McDiarmid [216], and Hayes [189]. A nocturnal frog that inhabits forested streams. Males are territorial and vigorously call from under leaves where females deposit their egg clutches. Physical combat occurs between males if another male intrudes into a male's territory despite the calls of the owner; both males may squeak during the fight; once one of the males is pinned venter down, he is held for a while, then leaves. Pale greenish–white eggs (25–40 in number) are deposited in a single-layer on the underside of a leaf. Males continue to advertise and may end up with as many as seven clutches from di fferent females. The males attend the eggs both during the day and at night. At night, the male continues to call and, occasionally exhibits hydric brooding behavior, in which he apparently empties his bladder over the eggs. Only males are involved in parental care of the eggs. McDiarmid [4] attributed the higher survivorship to hatching in this species than in the syntopic *Hyalinobatrachium colymbiphyllum* to the diurnal parental care. Vockenhuber et al. [239] experimentally verified the positive e ffect that parental care has on embryonic survivorship; also, they identified arthropod predation as the main cause for embryonic mortality.

**Call** (Figure 122): Males usually call from the underside of leaves, but sometimes they vocalize from the upper leaf surface. In Costa Rica, the call is a high-pitched *seet* lasting 200 to 250 milliseconds, with a dominant frequency initially of 7.0 kHz rising to 7.5 kHz and then dropping again to 7.2 kHz, repeated every 7 to 10 s [209]. Kubicki [24] reported call variation among Costa Rican populations. Below, we describe a call of an individual tentatively assigned to *Hyalinobatrachium valerioi* (USNM 201475) recorded near Santo Domingo de los Colorados by RWM; we analyzed 19 notes from one individual (Figure 122). Each note is composed by a single note. The note duration is 46–78 (mean = 72, SD = 7.7) ms. Notes are generally tonal and do not show any clear amplitude peaks throughout the note. The dominant frequency at peak amplitude is 5771–6632 (mean = 6197, SD = 253) Hz and is contained within the fundamental frequency. The fundamental frequency has a lower limit of 5599–5943 (mean = 5771, SD = 91) Hz and a higher limit of 6374–6718 (mean = 6632, SD = 76) Hz.

**Figure 122.** Call of a male (USNM 201475) tentatively assigned to *Hyalinobatrachium valerioi*, recorded near Santo Domingo de los Colorados, Ecuador, recorded by RWM.

**Egg masses and tadpoles:** The following information was obtained from Savage (2002) and incorporates data from McDiarmid and Adler [238], McDiarmid [216], and Hayes [189]. Green egg masses are deposited in a single-layer jelly mass on the underside of leaves; average clutch size is 35, with 40 eggs being the upper limit. Egg masses are attacked by diurnal wasps, which remove eggs one at a time and carry them away, presumably to a nest, until the egg mass is depleted [4]. Starrett [146] described the tadpole of *H*. *valerioi* as follows (as *Cochranella reticulata*): Tadpole similar to that of *H*. *fleischmanni*, but tail longer at hatching and color paler; tail of older tadpole two- and three-fifths times as long as body; dorsal part of body with brown blotches; tail musculature with brown blotches dorsally and laterally; pigment is in depressions between myotomes posteriorly; tail fins clear. Mouth ventral, nearly terminal; papillae surrounding all but anterior portion of the disc. LTRF 2(2)/3; A-1 complete, A-2 rows very short, occurring only lateral to the jaw sheaths; outermost posterior row not well developed at this stage (probably, in larger tadpoles, nearly as long as inner two); anterior jaw sheath is more heavily pigmented than the posterior one that is doubly arched and weakly pigmented medially, often appearing broken; posterior jaw sheath armed with small, equal length serrations. Ho ffmann [147] recently provided a very detailed description of the tadpole of the species. He mentioned that tadpoles of *H*. *valerioi* are distinguished by their accented slenderness and by the noticeably longer tail, about three times longer than the body; additionally, the oral disc of *H*. *valerioi* is more ventrally positioned than in other glassfrog species [147].

**Distribution** (Figure 123): As currently recognized, *Hyalinobatrachium valerioi* occurs from Costa Rica to southwestern Ecuador [156]. In Ecuador, it occurs in the northern and southern Pacific lowlands, foothills, and slopes below 1500 m in the provinces of Azuay, Carchi, Esmeraldas, Los Ríos, Pichincha, and Santo Domingo de los Tsáchilas (Specimens examined), within the Western Foothill Forest and Western Montane Forest ecoregions. In Ecuador, it has a potential distribution of 49,705 km2.

**Figure 123.** Distribution of populations tentatively assigned to *Hyalinobatrachium valerioi* in Ecuador (yellow dots).

**Conservation status:** Globally, *Hyalinobatrachium valerioi* is categorized as *Least Concern* by the IUCN [240]. The Ecuadorian populations currently assigned to *H*. *valerioi* (see Figure 123) might represent an undescribed species. The habitat of the species is severely fragmented, and the species

has exhibited populations declines in several historical localities (e.g., La Florida, Río Palenque, Manta Real; Luis A. Coloma, pers. comm.; JMG, pers. obs.). During the last year (2015–2019), we have found reproducing populations at Reserva Los Cedros and Reserva Mashpi. Based on the current available information, we sugges<sup>t</sup> that *H*. *valerioi* should be considered as *Endangered* in Ecuador (IUCN criteria A2c, A2e).

**Evolutionary relationships** (Figure 101): *Hyalinobatrachium valerioi* is the sister species to *H*. *aureoguttatum*.

**Taxonomic remarks:** The coloration of *Hyalinobatrachium valerioi* is variable across its distribution. Population may differ in having the pericardium completely transparent or covered with iridophores [24]. Also, at least in Costa Rica, there is notorious call variation [24]. At the moment, we are still uncertain about the taxonomic position of the populations from Ecuador; further studies are needed to assess if *H*. *valerioi*, as currently defined, is composed by several morphologically similar species.

**Specimens examined:** *Hyalinobatrachium valerioi:* Ecuador: *Provincia de Azuay:* 12.9 km W of Luz María, KU 217503–04. *Provincia de Carchi:* Maldonado, KU 178082–91. *Provincia de Cañar:* Manta Real (03◦10- S 80◦26- W), DHMECN 0134. *Provincia de Imbabura:* Reserva Los Cedros (0.3026◦ N, 78.781◦ W; 1360 m), MZUTI 3268. *Provincia de Los Ríos:* Río Palenque (0.55◦ S, 79.36667◦ W), USNM 286746–49, KU 147580, 164650. *Provincia de Santo Domingo de los Tsáchilas:* 5 km W of La Florida (0.25694◦ S, 79.0538◦ W; 860 m), QCAZ 12600, 27652; 4 km NE of Dos Ríos (0.25694◦ S, 79.0538◦ W), KU 164651–56; Río Faisanes (0.26083◦ S, 78.845◦ W). *Provincia de Pichincha:* Tandapi (0.41638◦ S, 78.7988◦ W), KU 178092; 1 km E of Pedro Vicente Maldonado (0.833◦ S, 79.0347◦ W; 670 m), QCAZ 12605; Reserva de Biodiversidad Mashpi (0.164◦ N, 78.867◦ W; 1080 m), MUTI 3921.

**Localities from the literature:** *Hyalinobatrachium valerioi:* Ecuador: *Provincia de Esmeraldas:* Bilsa Biological Station [160].

*Hyalinobatrachium yaku* Guayasamin, Cisneros-Heredia, Maynard, Lynch, Culebras, Hamilton 2017 [241] (Figures 124–126).

*Hyalinobatrachium yaku* Guayasamin, Cisneros-Heredia, Maynard, Lynch, Culebras, Hamilton, 2017 [241]. Holotype: MZUTI 5001.

Type locality: "Stream affluent of the Kallana river (1.4696◦ S, 77.2784◦ W, 325 m), nearby the Kichwa community of Kallana, province of Pastaza, Ecuador".

**Common names:** English: Yaku Glassfrog. Spanish: Rana de Cristal Yaku.

**Etymology:** The epithet *yaku* is the Kichwa word for *water* [241].

**Identification:** In life, *Hyalinobatrachium yaku* is distinguishable from all other glassfrogs by having middorsal dark green spots on the anterior half of the body and, ventrally, a completely transparent peritoneum and pericaridum (Figure 124).

**Diagnosis:** (1) Dentigerous process of the vomer lacking teeth; (2) snout truncated in dorsal and lateral views; (3) lower half of tympanic annulus visible; tympanic membrane clearly differentiated and with coloration similar to that of surrounding skin; (4) dorsal skin shagreen; (5) ventral skin areolate; cloacal area glandular, with tubercular and slightly enameled patch on each side of cloaca, lacking paired round subcloacal warts; (6) parietal peritoneum, pericardium, kidneys, and urinary bladder transparent (lacking iridophores); hepatic, gastrointestinal, and testicular peritonea covered by iridophores; (7) liver white, bulbous; (8) humeral spines absent; (9) basal webbing between Fingers I and II, moderate webbing between external fingers; hand webbing formula: I 2—2 II 0<sup>+</sup>—3<sup>+</sup> III 2−—(1–2−) IV; (10) foot webbing moderate; webbing formula: I (1–1<sup>+</sup>)—(2–2−) II (0<sup>+</sup>–1)—(2<sup>+</sup>–21/3) III 1—21/<sup>3</sup> IV 21/3—(1–11/3) V; (11) fingers and toes with thin lateral fringes; ulnar and tarsal folds present, but di fficult to distinguish, with thin layer of iridophores that extends to ventrolateral edge of Finger IV and Toe V; (12) nuptial excrescence present as a small pad on Finger I (Type V), concealed prepollex; (13) when appressed, Finger I longer than Finger II; (14) diameter of eye about 2.1 times wider than disc on Finger III; (15) coloration in life: Dorsal surfaces apple green to yellowish green with small yellow spots and minute grey to black melanophores; posterior head and anterior half of the body with few small, well-defined dark green spots placed mid-dorsally; bones white; (16) coloration in preservative: Dorsal surfaces pale cream with minute lavender to black melanophores; (17) iris coloration in life: Silver to yellow, with minute dark spots concentrated around pupil; (18) melanophores present on Finger IV and Toes IV–V, absent on other fingers and toes; in life, hands and feet are cream with a light green hue, with tips of fingers and toes being yellowish green; (19) males call from the undersides of leaves; advertisement call consisting of a single tonal note; call duration note 0.3–0.4 s, dominant frequency 5219–5330 Hz, with no frequency modulation; (20, 21) clutch size unknown; maternal care unknown; prolonged parental care provided by males; (22) tadpoles unknown; (23) adults small; SVL in adult males 20.8–22.3 mm (*n* = 3), in adult female 21.1 mm (*n* = 1).

**Figure 124.** *Hyalinobatrachium yaku* in life. (**Top row**): adult male, MZUTI 5001, holotype, in dorsal and ventral view. (**Bottom row**): adult male, paratype, QCAZ 55628. Obtained from Guayasamin et al. [241].

**Color in life** (Figure 124): In adults, dorsum apple green to yellowish green with small yellow spots and minute dark melanophores; posterior head and anterior half of the body with few small, well-defined dark green spots placed mid-dorsally, the anterior-most spot generally being the largest. Hands and feet cream with a light green hue, with tips of fingers and toes being yellowish green; melanophores absent from fingers and toes, except Finger IV and Toes IV and V. Ventrally, parietal peritoneum and pericardium transparent (red heart fully visible); visceral peritoneum of gall bladder and urinary bladder transparent; hepatic and visceral peritonea white. Ventral vein red. Iris silver to yellow, with minute dark spots that encircle the pupil, giving the impression of diffuse rings. Bones white [241].

**Color in ethanol:** Dorsal surfaces cream dotted with minute dark lavender to black melanophores; venter uniform white; peritonea as in life. Iris white with lavender melanophores that become more numerous near the pupil. There are no traces of the characteristic middorsal dark-green spots in preserved specimens [241].

**Variation:** Juveniles have the same color pattern as adults; the number and extent of the middorsal green dots varies, but they are usually smaller and less pronounced posteriorly [241].

**Biology and ecology:** Only basic biological information of *H*. *yaku* is known. The data presented below are from Guayasamin et al. [241]. Males call from the underside of leaves of riverine vegetation. One male (holotype) was on the same leaf as two egg clutches, approximately 3 m above the stream. Observations sugges<sup>t</sup> that prolonged parental care is provided by males. Syntopic species at the type locality are: *Nymphargus mariae*, *Teratohyla midas*, *Agalychnis hulli*, *Callimedusa tomopterna*, *Boana calcarata*, *B*. *geographica*, *Osteocephalus fuscifacies*, *Pristimantis enigmaticus*, and *P*. *peruvianus*. At the locality of Ahuano, the species was found along a small stream, tributary of the Arajuno River; the stream was slow flowing, very narrow (approximately 1 m wide), shallow (approximately 40 cm deep), and covered by secondary forest. At Ahuano, syntopic species were *Teratohyla midas* and *H*. *ruedai*. Individuals from San José de Payamino were found perched on leaves of small shrubs, ferns, and grasses (30–150 cm above ground) in disturbed secondary forest. Additionally, all individuals recorded at San José de Payamino were found >30 m from any stream. Syntopic species at San José de Payamino are reported by Maynard et al. [242].

**Call** (Figure 125): The information provided below is taken from Guayasamin et al. [241]. The advertisement call of *Hyalinobatrachium yaku* is a single and high-pitched tonal note, with no frequency nor amplitude modulation. The call lasts 0.27–0.4 s (0.3 ± 0.03) and has an average call rate of 9.0 calls/minute. Time between calls varied from 5.3–8.9 s (7.1 ± 1.1). The dominant frequency ranges from 5219–5330 Hz (5284 ± 35.0).

**Figure 125.** Call of *Hyalinobatrachium yaku* from Kallana, 325 m, Pastaza province, Ecuador; holotype, MZUTI 5001.
