AmphibiaWeb - Nymphargus lasgralarias
Nymphargus lasgralarias Hutter & Guayasamin, 2012
Las Gralarias Glassfrog; Rana de cristal de Las Gralarias
family: Centrolenidae
subfamily: Centroleninae
genus: Nymphargus
Species Description: Hutter CR, Guayasamin JM 2012 A new cryptic species of glassfrog (Centrolenidae: Nymphargus) from Reserva Las Gralarias, Ecuador. Zootaxa 3257:1-21.

© 2016 Laura Bravo Valencia (1 of 1)
Conservation Status (definitions)
IUCN Red List Status Account
National Status None
Regional Status None



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Nymphargus lasgralarias is a frog described from seven males having a snout-vent length of 24.6 - 26.5 mm and no females. The snout is truncated when viewed dorsally and protrudes when viewed laterally. The tympanum is small with the supratympanic fold being present. The dorsum lacks warts. The ventral skin is areolate with a pair of bulky, round warts located on the ventral surfaces of the thighs just below the vent. The cloaca is also surrounded by small, non-enameled warts. The species does not have humeral spines but does have ulnar and tarsal folds that are low and are hardly obvious and non-enameled. The species lacks palmar supernumerary tubercles. The nuptials pads of the hands are type I with the pre-pollex not separated from finger I. The first finger is somewhat shorter than the second. There is a lack of webbing between fingers and the toes are only half-webbed with a webbing formula is as follows: I (2 - 2-) - (2+ - 2 ½) II (2 - 2-) - (3- - 3) III (2- -2) - (3- - 3) IV (3 - 3+) - 2 V (Hutter and Guayasamin 2012).

Similarities exist between N. lasgralarias and other species of Nymphargus. The lack of webbing between fingers I - III and either lack or have reduced webbing between fingers III and IV, in addition to males (except in N. grandisonae) lacking humeral spines, is shared among all Nymphargus. These features in N. lasgralarias place it in Nymphargus. Nymphargus lasgralarias can be distinguished easily by its uniform green dorsum. In Nymphargus a few species lack spots: N. cristinae, N. prasinus, and N. woleyi. However, N. lasgralarias is smaller than N. cristinae (male snout-vent lengths are 26.0 - 31.1 mm), has a snout that is truncate when dorsally viewed and protrudes when laterally viewed, lacks vomerine teeth, and lacks palmar supernumerary tubercles (which are small, yet plentiful in N. cristinae). Nymphargus prasinus have a round snout when viewed dorsally, have 5 - 7 teeth on each process of the vomer, and are larger than N. lasgralarias. Nymphargus wileyi has kidneys that are coated by a white peritoneum with tiny, unpigmented spots (N. lasgralarias has kidneys are only covered by a uniform white layer). Confusion between N. lasgralarias and N. buenaventura and N. griffithsi can occur. Nymphargus buenaventura however, is smaller and has a light green dorsum with warts in pale, yellow spots, while N. lasgralarias is shagreen and is homogenously green. Nymphargus lasgralarias and N. griffithsi are the most similar in appearance, but differ in their dorsal color patterns. Nymphargus griffithsi has small black spots and/or small dark melanophores and has a background iris coloration of white silver with larger and less ample spots with moderate dark reticulation. Nymphargus griffithsi is also slightly smaller (Hutter and Guayasamin 2012).

In life, N. lasgralarias has a green dorsum that varies from very light to light green with small melanophores and flanks that are yellowish white. The dorsum lacks yellow spots. The tympanic membrane is translucent with coloration on the upper half only. The fingers and toes are yellow with a faint green tint. The background color of the iris is golden with several dark spots and slight reticulation (Hutter and Guayasamin 2012).

In preservative, the dorsal surface of the head, body, toes, and fingers become cream to medium-dark lavender colored. The upper section of the ventral parietal peritoneum is covered by iridophores, which are white, with all other peritonea becoming translucent except for a tiny layer of iridophores that coat the heart and renal capsules (Hutter and Guayasamin 2012).

There is variation in dorsal coloration between individuals in life and in preservative (Hutter and Guayasamin 2012).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador


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Nymphargus lasgralarias is only known from Reserva Las Gralarias, located within the Pichincha province, Ecuador at elevations between 1850 - 2200 m in primary montane forests with negligible disturbances. Within the reserve, N. lasgralarias has been found at the Chalguayacu River, Five Frog Creek, Heloderma Creek, Hercules Giant Tree Frog Creek, Kathy’s Creek, and Lucy’s Creek. It is absent from the Santa Rosa River (Hutter and Guayasamin 2012).

Life History, Abundance, Activity, and Special Behaviors
Nymphargus lasgralarias inhabits smaller permanent streams (approximately 3 meters wide) located within primary montane forests with negligible disturbances. It is active at night and emits calls typically from the tops of small ferns, leaves, and long palm leaves approximately 1 - 6 m above the streams (Hutter and Guayasamin 2012).

Reproduction has been observed taking place from April to July. Nymphargus lasgralarias males call from the upper sides of leaves that are located close to the stream and emit calls in a series of 1 - 4 calls with one note per call and 1 - 3 pulses per call. The calls sound like a pulsed “click” or “tick.” With typical durations of 0.0160 - 0.040 seconds and repeating 2 - 9.9 times per minute. These calls are non-modulated to weakly modulated with dominant frequencies at 3445.3 - 3962.2 Hz. It is unknown if males engage in aggressive fighting behaviors (Hutter and Guayasamin 2012).

Egg clutches are deposited on the upper surfaces of leaves at the terminal margin, transitioning to hanging as the eggs fully develop. Egg clutches typically contain 12 - 36 eggs. The tadpole type is unknown (Hutter and Guayasamin 2012).

Nymphargus lasgralarias occurs sympatrically with the following members of Centrolenidae: Centrolene ballux, Centrolene heloderma, Centrolene lynchi, Centrolene peristictum, Nymphargus grandisonae, and Nymphargus griffithsi. Other anuran species sympatric along the creeks include: Hyloscirtus alytolylax, Pristimantis eugeniae, Pristimantis calcarulatus, Pristimantis parvillus, and Pristimantis wnigrum (Hutter and Guayasamin 2012).

Nymphargus lasgralarias was distinguished as a new species based on morphology and vocalizations. At the time of the species description, no analyses were performed to determine phylogenetic relationships (Hutter and Guayasamin 2012).

The species epithet, “lasgralarias” refers to the type locality of the new species found on Reserva Las Gralarias (Hutter and Guayasamin 2012).


Hutter, C. R., Guayasamin, J. M. (2012). "A New Cryptic Species of Glassfrog (Centrolenidae: Nymphargus) from Reserva Las Gralarias, Ecuador." Zootaxa, 3257, 1-21. [link]

Originally submitted by: Bryan Hicks (2022-10-06)
Description by: Bryan Hicks (updated 2022-10-06)
Distribution by: Bryan Hicks (updated 2022-10-06)
Life history by: Bryan Hicks (updated 2022-10-06)
Comments by: Bryan Hicks (updated 2022-10-06)

Edited by: Ann T. Chang (2022-10-06)

Species Account Citation: AmphibiaWeb 2022 Nymphargus lasgralarias: Las Gralarias Glassfrog; Rana de cristal de Las Gralarias <> University of California, Berkeley, CA, USA. Accessed Nov 30, 2022.

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Citation: AmphibiaWeb. 2022. <> University of California, Berkeley, CA, USA. Accessed 30 Nov 2022.

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