Limosa Harlequin Frog
© 2013 Brian Freiermuth (1 of 26)
Atelopus limosus can be distinguished from other Atelopus species by a combination of the following characters: pointed snout, small defined parotids, absent tympanum, smooth dorsal skin, cracked ventral skin, vestigial webbing on the hands, slender fingers except the thumb, moderate webbing on the feet, absent tarsal fold, heel reaching the posterior border of the orbit when limb extended along body, typically dark green dorsal coloring which may be olive brown in females, males with a black lateral line dividing the back and underside, typically white ventral coloring with small black spots on males and partial to complete orange ventral coloration in females. Furthermore, A. limosus can be distinguished from A. certus, A. chiriquiensis, A. glyphus, A. senex, A. varius, and A. zeteki by its dark green or olive brown back with no spots, and the males have a black line running down the sides of its chest (Ibáñez et al. 1995).
In life, this species usually has a solid dark green black that may be olive brown in females. Males have a black line dividing the underside and back, which may be thin, irregular or thick. The underside of males is typically white with small black spots, particularly on the throat. The posterior end of the underside may be orange in some males. The underside of females is completely or partially orange, but some white coloration and yellow and green spots may also be present. The thighs may be grayish yellow, the arms are white, and palms and fingertips are yellow. The iris is green. In preservative, the back is dark gray. The flank is gray with a dark line separating the back from the underside, which is white with scattered black spots (Ibáñez et al. 1995).
There are two varieties of this species: the lowland variety may be brown with yellow nostrils and fingertips, whereas the highland variety may be green and yellow with a black V-shaped pattern on its body (Wilson 2014).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
A mating pair was observed one November (during the rainy season); in this instance, the frogs were engaged in axillary amplexus on a rock jutting out over a stream (Ibáñez et al.1995).
Embryos hatch as free-living larvae, and they use their ventral suction disks to cling to rocks in flowing streams. More than 50 tadpoles may hatch per clutch, and highland tadpoles are nocturnal (Amphibian Ark 2009a, Amphibian Ark 2009b).
Atelopus limosus males call. Two call types have been noted: the advertisement call and the short call. The advertisement call occurs at average ambient temperatures of 26°C and lasts 260 ± 30 milliseconds at a dominant frequency of 2689 Hz. This call is described as sharp soft trill with pulses that gradually increase in amplitude and frequency and then decrease in amplitude. The call is similar to that of A. varius and A. zeteki, though it is of a shorter duration, consists of more pulses per second and is a higher frequency. Between advertisement calls at the edge of a stream, a male was observed to move in a < 50 cm radius while occasionally waving his left arm and extending both rear limbs in a motion described as a horse kick. Both these limb movements displayed the yellow areas on the palms and toe tips (Ibáñez et al. 1995).
The short call occurs at average ambient temperatures of 21°C and lasts 10 ± 3 milliseconds at a dominant frequency of 2082 ± 44 Hz. This call occurs when the male is handled, and it is described as a soft cheeping sound. The short call of A. limosus is similar to that of A. zeteki but is of shorter duration and higher frequency (Ibáñez et al. 1995).
Trends and Threats
The population size was noted to be stable and reasonably common up till 2009 but is now declining dramatically, and it is predicted that the entire Atelopus genus will soon be extinct. These dramatic declines are largely attributed to decreases in the extent and quality of its forest habitat due to agriculture and infrastructure development. Other habitat threats include water pollution from domestic and urban wastewater, erosion, stream sedimentation, and mining and quarrying activities. Gold mining has been particularly damaging to local habitats, and this has been suggested as a threat especially to egg and larval development (Ibáñez et al. 1995, Luger et al. 2009, Stuart et al. 2008).
Though other members of Atelopus have been severely affected by chytridiomycosis, some scientists postulate that A. limosus occurs at a low enough altitude where the disease is less impactful. Studies have shown that lowland frogs are able to inhibit the growth of chytrid fungus on their skin due to increased ambient temperatures. Bacteria found on the skin of A. limosus may also play a role in its protection from the fungus, though this is not entirely certain (Flechas et al. 2012, Stuart et al. 2008).
As a result of its endangered status, the Panama Amphibian Rescue and Conservation Project has a captive-breeding project for Atelopus limosus (Wilson 2014).
Relation to Humans
Possible reasons for amphibian decline
General habitat alteration and loss
Amphibian Ark (2009a). ''Progress of amphibian ex situ conservation program: Atelopus limosus (lowland).'' http://www.amphibianark.org/exsituprogress/Atelopus%20limosus%20%28Lowland%29.htm.
Amphibian Ark (2009b). ''Progress of amphibian ex situ conservation program: Atelopus limosus (upland).'' http://www.amphibianark.org/exsituprogress/Atelopus%20limosus%20%28Upland%29.htm.
Flechas, S. V., Sarmiento, C., Cárdenas, M. E., Medina, E. M., Restrepo, S., Amézquita, A. (2012). ''Surviving chytridiomycosis: Differential anti-Batrachochytrium dendrobatidis activity in bacteria isolates from three lowland species of Atelopus.'' PLOS ONE, 7(9), e44832. [link]
Frost, D. R., Grant, T., Faivovich, J., Bain, R. H., Haas, A., Haddad, C. F. B., de Sá, R. O., Channing, A., Wilkinson, M., Donnellan, S. C., Raxworthy, C. J., Campbell, J. A., Blotto, B. L., Moler, P., Drewes, R. C., Nussbaum, R. A., Lynch, J. D., Green D. M., Wheeler, W. C. (2006). "The amphibian tree of life." Bulletin of the American Museum of Natural History, 297, 1-370. [link]
Ibáñez, R. D., Jaramillo, C. A., Solís, F. A. (1995). ''Una especie nueva de Atelopus (Amphibia: Bufonidae) de Panama.'' Carribean Journal of Science, 31(1-2), 57-64.
La Marca, E., Lötters, S., Puschendorf, R., Ibáñez, R., Rueda-Almonacid, J. V., Schulte, R., Marty, C., Castro, F., Manzanilla-Puppo, J., García-Pérez, J. E., Bolaños, F., Chaves, G., Pounds, J. A., Toral, E., and Young, B. E. (2005). ''Catastrophic population declines and extinctions in neotropical harlequin frogs (Bufonidae: Atelopus).'' Biotropica, 37(2), 190-201.
Luger, M., Hoedl, W., Loetters, S. (2009). ''Site fidelity, home range behavior and habitat utilization of male harlequin toads (Amphibia: Atelopus hoogmoedi) from Suriname: important aspects for conservation breeding.'' Salamandra, 45(4), 211-218.
Pessier, A. P., Baitchman, E. J., Crump, P., Wilson, B., Griffith, E., Ross, H. (2014). ''Causes of mortality in anuran amphibians from an ex situ survival assurance colony in Panama.'' , 33, 516-526.
Pramuk, J. B., Robertson, T., Sites Jr., J. W., Noonan, B. P. (2008). ''Around the world in 10 million years: biogeography of the nearly cosmopolitan true toads (Anura: Bufonidae).'' Global Ecology and Biogeography, 17, 72-83.
Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
Wilson, D. (2014). ''Frog Friday: Limosa Harlequin Frog. Panama Amphibian Rescue and Conservation Project.'' http://amphibianrescue.org/2014/10/03/atelopuslimosus/.
Yotsu-Yamashita, M., Tateki, E. (2010). ''First report on toxins in the Panamanian toads Atelopus limosus, A. glyphus and A. certus.'' Toxicon , 55, 153-156.
Originally submitted by: Melissa Sullivan (first posted 2015-07-01)
Edited by: Gordon Lau (2015-07-06)
Species Account Citation: AmphibiaWeb 2015 Atelopus limosus: Limosa Harlequin Frog <https://amphibiaweb.org/species/5540> University of California, Berkeley, CA, USA. Accessed Jun 29, 2022.
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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 29 Jun 2022.
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