Species Description: O'Neill EM, Mendelson III JR 2002 Taxonomy of Costa Rican toads referred to Bufo melanochlorus Cope, with the description of a new species. J Herp 38:487-494
© 2013 Fabio Hidalgo (1 of 3)
The body is robust. Many small, spiculate tubercles are scattered in the interspaces between the cranial crests. Bufo aucoinae lacks transverse folds between the parietal crests. The body dorsal skin has evenly distributed small, spiculate tubercles of relatively equal size, which become larger and less numerous laterally. There are enlarged tubercles in two paravertebral rows. The parotoid gland is smaller than the eyelids, triangular, and extends posteriorly at about 45º to the midline of the body. A lateral row of enlarged tubercles is present or weakly spiculate. The dorsal surfaces of the limbs are covered with small spiculate tubercles, and the skin on the throat and other ventral surfaces is granular. The forelimb is short and robust, and the hand is broad with short, slender fingers. Relative finger length is III > I > IV > II, and webbing and lateral fringes on the fingers are absent. The tips of the fingers are not enlarged, are smooth dorsally, and are demarcated proximally by a distinct dermal fold. The palmar tubercle is distinct, large, subcircular, and larger than the pollical tubercle, and the pollical tubercle is ovoid in shape. Subarticular tubercles are distinct, elevated, triangular in profile, and single except for a distal tubercle on fingers I, III, and IV. Small and distinct supernumerary tubercles of unequal size are scattered evenly over the palm and ventral surfaces of fingers. The hind limbs are long and slender. The tarsal fold is absent. The outer metatarsal tubercle is very small, elevated, and ovoid, while the inner metatarsal tubercle is slightly larger, distinctly elevated, and also ovoid. The toes are long and slender, with relative lengths IV > III > II > I. Lateral fringe is present on all toes. Webbing is thin. The toe tips are smooth dorsally and demarcated proximally by a distinct dermal fold. Subarticular tubercles on the feet are distinct, elevated, triangular in profile, and single. Distinct supernumerary tubercles are also distributed evenly over the ventral surfaces of the feet and toes (O'Neill and Mendelson 2004).
Nuptial pads are present as brown granular patches on dorsal surfaces of Finger I and medial surface of Finger II. Male dorsal spiculae are smaller and more concentrated than female dorsal spiculae. The lateral row of tubercles are present as a series of low, rounded tubercles in males and large, sharply pointed spiculae in females (O'Neill and Mendelson 2004).
In ethanol preservative, the dorsum of the body is dull brown medially, shading to gray-brown laterally. The top of the head is gray-brown. Color is reduced on the preorbital crest. A lateral row of tubercles coincides with the boundary between the dorsolateral coloration and dark brown lateral coloration. The flanks are slightly paler than the dorsolateral area. Dorsal markings consist of a thin, pale gray dorsal stripe. The dorsal surfaces of the arms and legs are dull brown, and many of the tubercles have red-brown apices. The forearm has a distinct, wide, dark transverse bar. Dark brown lateral coloration extends anteriorly over the tympanic area. Loreal and suborbital regions are dull brown. The lip is pale cream and the parotoid glands are gray-brown. The throat is dull cream and becomes a paler cream anteriorly. The venter is pale cream, and ventral surfaces of the hands are dull cream with pale cream tubercles. The ventral surfaces of the forearms are dark brown, and the ventral surfaces of the legs are dull cream. The mid-dorsal stripe may be faint or distinct. Gray spots are sometimes present on males. Ventral surfaces are usually plain and lack dark markings on the throat and venter, although faint mottling on the chest and throat may be present. Dorsal spiculae and cranial crests may appear distinctly red-brown in color. Juveniles show similar color pattern variation, but have a darker ventral region. This dark ventral coloration fades to the typical plain cream color as the individual matures (O'Neill and Mendelson 2004).
Bufo aucoinae is similar to B. melanochlorus, but can be distinguished by its lack of transverse folds between the parietal crests, weak or absent pretympanic and preorbital crests, relatively unmarked venter, and relatively small and unpigmented vocal sac (O'Neill and Mendelson 2004).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Costa Rica, Panama
Life History, Abundance, Activity, and Special Behaviors
Bufo aucoinae is syntopic with Smilisca sordida, but does not readily feed on S. sordida eggs (Malone 2006).
Trends and Threats
Possible reasons for amphibian decline
General habitat alteration and loss
A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).
IUCN, Conservation International, and NatureServe. (2006). Global Amphibian Assessment: Bufo aucoinae. www.globalamphibians.org. Accessed on 14 November 2007.
Malone, J. H. (2006). ''Ecology of the basin construction reproductive mode in Smilisca sordida (Anura: Hylidae).'' Journal of Herpetology, 40(2), 230-239.
O'Neill, E. M., and Mendelson III, J. R. (2004). ''Taxonomy of Costa Rican toads referred to Bufo melanochlorus Cope, with the description of a new species.'' Journal of Herpetology, 38(4), 487-494.
Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica:a herpetofauna between two continents, between two seas. University of Chicago Press, Chicago, Illinois, USA and London.
Originally submitted by: Christin Hong (first posted 2007-11-14)
Edited by: Christin Hong (2009-11-02)
Species Account Citation: AmphibiaWeb 2009 Incilius aucoinae <https://amphibiaweb.org/species/6409> University of California, Berkeley, CA, USA. Accessed Jun 18, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 18 Jun 2021.
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