Research Article |
Corresponding author: José Rogelio Cedeño-Vázquez ( rogeliocedeno@gmail.com ) Academic editor: Johannes Penner
© 2019 Rubén Alonso Carbajal-Márquez, Luis F. Díaz-Gamboa, Tania Ramírez-Valverde, Christian M. García-Balderas, Pedro E. Nahuat-Cervera, José Rogelio Cedeño-Vázquez.
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Citation:
Carbajal-Márquez RA, Díaz-Gamboa LF, Ramírez-Valverde T, García-Balderas CM, Nahuat-Cervera PE, Cedeño-Vázquez JR (2019) Description of the male of Craugastor yucatanensis (Lynch, 1965) (Anura, Craugastoridae), its advertisement call, and additional data on females. ZooKeys 900: 129-139. https://doi.org/10.3897/zookeys.900.37591
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The male of Craugastor yucatanensis (Lynch, 1965) is described for the first time, as the original description was based on four females. The advertisement call is described and additional morphological data on females are presented. Also, information is provided on the sexual dimorphism and natural history of the species.
Natural history, sexual dimorphism, vocalization, Yucatán Rainfrog
We conducted field trips in 2015–2018 to locate individuals of C. yucatanensis in the vicinity of the type locality at Nuevo Xcán, Quintana Roo, Mexico. Specimens used in the description are deposited in the herpetological collection of El Colegio de la Frontera Sur (ECOSUR) at Chetumal, Quintana Roo, Mexico (ECO-CH-H). We followed
We recorded advertisement calls of male frogs while they were actively calling in the field, using the WavePad free recording software (NCH Software 2015) on a Samsung Galaxy J7 smartphone with an internal directional microphone. We recorded the calls at distances of 50–150 cm. Digital sonograms were executed to identify the frequencies emitted, as well as determine the other sound sources that also formed part of the landscape. We selected the frequencies of the species to later filter unwanted frequencies through multiple parametric equalizers using the Ableton Live 10 program (
Craugastor yucatanensis (23). Mexico – Quintana Roo State: Benito Juárez Mun. ECO-CH-H-1655; Felipe Carrillo Puerto Mun. ECO-CH-H-1878, 1904, 1932, 1949, 2014, 2015, 2016, 2042, 2105, 2393, 3538 –Yucatán State: Chemax Mun. ECO-CH-H-3790, 3791, 3792, 3793, 4537, 4538, 4539, 4540, 4541, 4542; Tinum Mun. ECO-CH-H-3539.
A member of the Craugastor (Hylactophryne) bocourti species series, most closely related to C. alfredi (Boulenger, 1898) (Lynch, 1965), characterized by having greatly expanded and truncate digital pads on the outer two fingers, possessing no vocal sac or slits (Fig.
Adult males (N = 19) averaged SVL = 27.1 ± 1.7 mm (range 24.2–30.5 mm). Head somewhat broader (HW = 11.2 ± 0.9 mm [9.6 – 13.2]) than long (HL = 10.5 ± 0.6 mm [9.7–12.1]). Tympanum distinct, more than two-thirds the diameter of the eye (TM = 2.8 ± 0.2 mm [2.4–3.2]). Eye slightly longer (EL = 3.7 ± 0.3 mm [3.1–4.4]) than distance from EN = 3.6 ± 0.3 mm [3.1 – 4.0]). Average IOD = 3.4 ± 0.3 mm (2.8–4.0). Canthus rostralis rounded; loreal region slightly concave; tympanum transparent with a dark spot in the center; no dorsolateral, paravertebral, or occipital folds; supra and post-tympanic folds not distinct. Dorsum smooth; skin on venter smooth except for ventral surface of thigh which is areolate; scattered melanophores on chin, chest, and limbs; ventral disc present although obscure; posterior border of thighs slightly granular (Fig.
Tips of fingers expanded, slightly emarginate; the width of pad of 3rd finger (F3) averages 1.6 ± 0.2 mm (1.2–2.1); thumb with an enlarged thenar tubercle, almost as large as semi-divided cordiform palmar tubercle; subarticular tubercles round to slightly obtuse and projecting in lateral profile, rounded to ovoid in basal outline, Fingers I and II with one, Fingers III and IV with two; accessory palmar tubercles globular to slightly conical in lateral profile, rounded in basal outline; first finger as long as second; with two white glandular nuptial pads, one on thenar tubercle and the other, also on pollex, opposite and slightly lateral to distal subarticular tubercle (Fig.
Adult females (N = 8; including four from the original description) had an average SVL = 35.0 ± 1.9 mm (range 31.2–37.1 mm). Head is broader (HW = 14.1 ± 1.1 mm [12.5–15.1]) than long (HL = 13.1 ± 1.7 mm [11.8–17.1]). Tympanum distinct, half the diameter of the eye (TM = 2.5 ± 0.4 mm [2.0–3.1]). Eye slightly shorter (EL = 4.7 ± 0.4 mm [4.1–5.1]) than distance from EN = 4.9 ± 0.3 mm [4.4–5.3]). Average IOD = 4.0 ± 0.3 mm (3.4–4.5). Canthus rostralis rounded; loreal region slightly concave; no dorsolateral, paravertebral, or occipital folds; supra and post-tympanic folds not distinct. Tips of fingers expanded, slightly emarginate; the width F3 = 2.3 ± 0.4 mm (1.6–2.7). Tibia length averages 18.2 ± 1.0 mm (17.0–20.4).
The coloration depends on the substrate and the time when the specimens are found. When males are active at night over vegetation or leaf litter, they have an Olive Yellow (117) to Smoke Gray (267) dorsal coloration, with Glaucous (289) to Sepia (279) blotches on dorsum and bars on limbs; sometimes a thin clear vertebral stripe is distinguishable (Fig.
Dorsum Pale Neutral Gray (296), with Glaucus (289) to Brownish Olive (292) blotches on dorsum and bars on limbs; pupil Smoky White (261), iris and upper eyelid Grayish Olive (273); tympanum Pale Cinnamon (55); venter semi-transparent or Pale Buff (1) to Pale Pinkish Buff (3) (Fig.
The advertisement call of Craugastor yucatanensis is part of a communication system that consists of repetitive notes emitted every 10 seconds (6 times per minute). Every note has a duration of approximately 460 MS at a dominant frequency around 2600 kHz. These notes sound like a very short “peep” that resembles the weak chirping of a bird chick (Fig.
Craugastor yucatanensis is known from near sea level to 60 m elevation throughout its range on the central and northeastern portion of the Yucatán Peninsula (
Only males have prepollical nuptial excrescences. There was a significant difference between the SVL of adult males and females of C. yucatanensis (t = -9.72, df = 25, P < 0.05). When the effect of body length (SVL) was removed, there was a significant difference between sexes in TM (F1,24 = 11.21, P < 0.05), where males possess larger TM average, SL (F1,24 = 4.87, P < 0.05) where females are larger in average, and EN (F1,24 = 12.61, P < 0.05) where females possess larger EN. There was no significant difference in EL (F1,24 = 1.26, P > 0.05), IOD (F1,24 = 0.01, P > 0.05), F3 (F1,24 = 0.11, P > 0.05), HL (F1,24 = 3.14, P > 0.05), and HW (F1,24 = 0.48, P > 0.05) between sexes.
Craugastor yucatanensis is the only member of the genus occurring in the central and northeastern portion of the Yucatán Peninsula (Quintana Roo and Yucatán), while C. alfredi is known from the base of the Peninsula (Chiapas, Tabasco, and Guatemala). Increased sampling efforts in current range gaps are necessary to improve our understanding of the distribution of both species. Here we describe the previously unknown male, and document the arboreal behavior and advertisement call of C. yucatanensis, previously mentioned but with little detail by
Here we demonstrate that C. yucatanensis possesses an advertisement call, despite the absence of vocal slits and sac in both sexes.
We thank Robert W. Hansen for comments on a previous version of the manuscript, and the anonymous reviewers whose comments improved the final version. We thank Marco A. Dominguez-De la Riva and Francesca M. Cassola for field assistance. We thank Humberto Bahena Basave for taking, and editing photographs, Julio C. Gutiérrez and N. Gabriela Blanco Campos provided laboratory support. We thank David Escalante Euán and Amauri Sarmiento Rojas for the redesign of sound samples and advice in the bioacoustic analysis. We thank all the local people for allowing us access to their land. Sampling and collecting permits were provided by Dirección General de Vida Silvestre of the SEMARNAT (SGPA/DGVS/02570/15, SGPA/DGVS/1629/16, SGPA/DGVS/01205/17, SGPA/DGVS/002491/18) to Fausto R. Méndez-de la Cruz with an extension to JRCV of Departmento de Sistemática y Ecología Acuática at El Colegio de la Frontera Sur.