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| Scinax tsachila |
Abstract
Scinax is a speciose genus of Neotropical hylid frogs. We describe a new species from western Ecuador (elevations between 0 and 1207 m) using morphology, vocalizations, and DNA sequences. We also present a new phylogeny for Scinax based on mitochondrial DNA genes 12S rRNA, Cytochrome Oxidase sub-unit I, Cytochrome B, 16S rRNA, NADH dehydrogenase subunit 1, and adjacent tRNAs. The new species, Scinax tsachila sp. nov. was previously confused with S. quinquefasciatus, a morphologically similar sympatric species. They differ by having markedly different advisement calls, distinct skin texture in the dorsum, and different bone coloration. The new species is sister to S. elaeochroa, a species that differs in advertisement call and color pattern. We provide an updated species account for Scinax quinquefasciatus and a redescription of its holotype.
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| Scinax tsachila. A–B. QCAZ 39880, holotype, adult male, SVL 27.2 mm, Santa Rosa, Provincia El Oro, Ecuador. C. Amplectant pair, QCAZ 40848, adult male SVL 31.2 mm; QCAZ 40849, adult female, SVL 32.1 mm, Playón de San Francisco, Provincia Esmeraldas, Ecuador. D. QCAZ 62975, adult male, SVL 32.7 mm, vía Zaracay-Piñas, Provincia El Oro, Ecuador. E–F. QCAZ 57045, subadult female, SVL 24.6 mm, Tundaloma Lodge, Provincia Esmeraldas, Ecuador.
Photos A–F by S. R. Ron
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Scinax tsachila sp. nov.
Diagnosis: (1) Average SVL in males 31.6 mm (range 27.2–34.2), in females 34.7 mm (range 33.2–36.4), Table 3; (2) snout acutely rounded in dorsal view and in profile; (3) ulnar and tarsal tubercles absent; (4) enlarged heel tubercle absent; (5) tubercles absent on lower jaw; (6) skin on dorsum smooth to shagreen without scattered tubercles; (7) diameter of tympanum 15.0% of head length; (8) dorsum cream to reddish brown with or without longitudinal brown stripes; (9) flanks lacking patterns; (10) posterior surfaces of thighs without markings; (11) iris brown with orange flecks to orange-yellow with brown reticulations.
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Fig 8. Scinax tsachila [A–F] and S. elaeochroa [G–H] in life.
A–B. QCAZ 39880, holotype, adult male, SVL 27.2 mm, Santa Rosa, Provincia El Oro, Ecuador. C. Amplectant pair, QCAZ 40848, adult male SVL 31.2 mm; QCAZ 40849, adult female, SVL 32.1 mm, Playón de San Francisco, Provincia Esmeraldas, Ecuador. D. QCAZ 62975, adult male, SVL 32.7 mm, vía Zaracay-Piñas, Provincia El Oro, Ecuador. E–F. QCAZ 57045, subadult female, SVL 24.6 mm, Tundaloma Lodge, Provincia Esmeraldas, Ecuador.
G. KU 64336, adult male, 35.3 mm SVL, Quebrada Boruca, Puntarenas, Costa Rica. H. KU 64499, adult male, 30.7 mm, Laguna Monte Alegre, Alajuela, Costa Rica.
Photos A–F by S. R. Ron, G-H by W. E. Duellman.
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| Fig 10. Reproduction in Scinax tsachila. A. Amplectant pair (not collected). B. Eggs. Photos by Pol Pintanel. Ecuador, Provincia Pichincha, Mindo, near the juncture of Río Cinto and Río Seloya. |
Distribution and ecology: Scinax tsachila occurs in the Pacific Basin of Ecuador. Specimens with elevation data range from 0 to 1207 m above sea level (near Mindo, Provincia Pichincha; Fig 6). The available evidence suggests the occurrence of S. tsachila in Colombia. Records of “S. elaeochroa” from, Nariño Department, Colombia, [62,63] likely represent S. tsachila as some of they are only 70 km from S. tsachila populations in Ecuador. ....
Etymology: The specific name is a noun in apposition. The epithet refers to the Tsáchila people who inhabit the area within the range of Scinax tsachila in Ecuador. Men in this ethnic group mold their hair into a helmet-like shape that is dyed red with the juice of the achiote bush (Bixaceae: Bixa orellana). The Spaniards called them “Colorados” (colored red). Hence the former name of the major population center in the area, Santo Domingo de los Colorados.
Remarks: A potential senior synonym for S. tsachila is Hyla dulcensis [65]. Its type locality is “Golfito, Puntarenas Province, Costa Rica”. Hyla dulcensis was considered a junior synonym of S. elaeochroa by Duellman [66]. Examination of the holotype of H. dulcensis (KU 32168) confirms that it is not conspecific with S. tsachila. The holotype has the characteristic dark interorbital triangular mark present in most S. elaeochroa. This is supported by the phylogeny which shows that samples of S. elaeochroa from Costa Rica, which are geographically close to the type locality of H. dulcensis, are genetically distinct from those of S. tsachila.
Santiago R. Ron , William E. Duellman, Marcel A. Caminer and Diana Pazmiño. 2018. Advertisement Calls and DNA Sequences Reveal A New Species of Scinax (Anura: Hylidae) on the Pacific Lowlands of Ecuador. PLoS ONE. 13(9): e0203169. DOI: 10.1371/journal.pone.0203169
