Description
Alsodes norae is a robust, medium-sized frog with SVL length ranging from 30.6mm-61.4mm for adults and 28.9-29.9mm for juveniles. The head is wider than long. Snout is slightly truncated. Canthus rostralis is prominent and appears curved, and the loreal region is slightly concave, with smooth skin. Nostrils are situated anterolaterally, closer to the tip of the snout than the anterior border of the eyes. A well-developed postocular fold is present, reaching past the insertion of the arms. Tongue is rounded and the tip is notched. Choanae appear round, and vomerine teeth are aligned between the choanae. Fingers are long with white rounded tips, decrease in length from IV>III>II=I, and lack webbing. Carpal elements are cartilaginous rather than ossified. Palmar tubercles are distinct; the inner tubercle being oval-shaped and larger than the outer palmar tubercle, and the outer being bifid. Hind limbs have the tibiotarsal joint extending as far as the anterior border of the eye. Toes are slender and elongated, with rounded white tips, and prominent fringing. Toes decrease in length from IV>V>III>II>I. Inner metatarsal tubercle is well developed and oval shaped. Tarsal fold is prominent, flanks quite granular, and dorsal surface moderately rough. Arms, legs, and ventrum are smooth, and skin around vent and posterior thighs is grainy. Males have rounded spiny patches on the thumb and thorny asperities on fingers I and II as well as on two distinct bilateral round patches on the chest (Formas et al. 2002; Cuevas 2008). Forelimbs of males are not hypertrophied (Cuevas 2008). Diagnostic morphological traits for the genus include the absence of the tympanum, an arciferal xiphisternum, and male thorny excrescences on both the thumb and chest (Cei 1980; Formas et al. 1998; Cuevas and Formas 2001).

In life, Alsodes norae exhibits vivid yellow and black coloration with a slight granular appearance on the dorsal surfaces of the head, forelimbs, and hindlimbs. A yellowish triangle is present on the head, between the snout tip and the anterior border of the eyes. There is a dark bat-shaped marking with spread wings along the dorsal surface of the head down to the mid-body. Thin dark transverse bars are present on the dorsal surfaces of the hindlimbs. Ventral surfaces of thighs are yellow, and the venter is light beige with dark reticulations. The top part of the iris is golden or bronze-yellowish with black reticulations (Cuevas 2008).

In preservative, the dorsal surface of head, forelimbs, hindlimbs, and body appear slightly grey. The dark bat figure is visible in preserved specimens, extending from mid eye level to the insertion of arms, and continuing to the vent in the form of many parallel lines. A light gray triangular marking is present on the head. A dark line passes over the postocular fold. The venter, throat, and ventral surfaces of arms and thighs have dark reticulations in younger animals and are whitish in older specimens (Cuevas 2008).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Chile

View distribution map in BerkeleyMapper.

Endemic to the Coastal Range, Valdivia Province, Chile. Alsodes norae is known only from the type locality, Parque Oncol, a small woody area (754 ha) at 720 m elevation (Cuevas 2008). The type locality is recognized as a fragmented area of the original Valdivian rain forest (Veblen et al. 1980), mainly dominated by Eucryphia cordifolia and Aextoxicum punctatum vegetation (Oberdorfer 1960). The Valdivian rainforest region has a west coast maritime climate characterized by annual average temperature of 10.5C and rainfall of 2000-2500mm per year (Cuevas 2008). Specimens were found under fallen logs in the humid forests (Cuevas and Formas 2005; Cuevas 2008).

Life History, Abundance, Activity, and Special Behaviors
Tadpoles have yet to be found (Cuevas 2008).

Comments
The species name norae was given to honor the author's grandmother (Cuevas 2008).

The diploid chromosome number is 30, unlike all other Alsodes from the Coastal Range: A. barrioi 2n=34; A. nodosus 2n=22; A. valdiviensis 2n=26; A. vanzolinii 2n=26. (Cuevas and Formas 2005; Cuevas 2008). In addition, A. norae has four uniarmed pairs of chromosomes, while A. barrioi has eight, A. valdiviensis has none, and A. vanzolinii has one pair of uniarmed chromosomes; A. nodosus was not reported (Cuevas 2008). A nucleolar organizing region (NOR) is present on chromosome pair 4 in Alsodes norae (Cuevas 2008).

References

Cei, J. M. (1980). ''Amphibians of Argentina.'' Monitore Zoologica Italiano, New Series Monografia, Firenze, 2, 1-609.

Cuevas P., C. C. (2008). ''A new species of the genus Alsodes (Anura: Neobatrachia) from the Nothofagus forest, coastal range, southern Chile, identified by its karyotype.'' Zootaxa, 1771, 43-53.

Cuevas, C. C. and Formas, J. R. (2005). ''A new frog of the genus Alsodes (Leptodactylidae) from the Tolhuaca National Park, Andes Range, southern Chile.'' Amphibia-Reptilia, 26, 39-48.

Cuevas, C. C., and Formas, J.R. (2001). ''A new species of Alsodes (Amphibia, Anura, Leptodactylidae) from Central Chile.'' Amphibia-Reptilia, 22, 187-198.

Formas, J. R., Cuevas, C. C., and Brieva, L. M. (2002). ''A new species of Alsodes (Anura, Leptodactylidae) from Cerro Mirador, Cordillera Pelada, southern Chile.'' Proceedings of the Biological Society of Washington, 115, 708-719.

Formas, J. R., Cuevas, C. C., and Nuñez, J. (1998). ''A new species of Alsodes (Amphibia, Anura, Leptodactylidae) from Southern Chile.'' Proceedings of the Biological Society of Washington, 115, 708-719.

Oberdorfer, E. (1960). ''Pflanzensoziologische Studien in Chile. Ein Vergleich mit Europa.'' Flora et Vegetatio Mundi, 2, 1-208.

Veblen, T. T., Schlegel, F. M., and Oltremari, J. V. (1980). ''Temperate broad-leaved evergreen forest of South America.'' Temperate Broad-Leaved Evergreen Forests. J. D. Ovington, eds., Elsevier Science Publishers, Amsterdam.

Species Account Citation: AmphibiaWeb 2009 Alsodes norae <https://amphibiaweb.org/species/7115> University of California, Berkeley, CA, USA. Accessed Dec 30, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 30 Dec 2024.

AmphibiaWeb's policy on data use.