Adult: Species description based on Savage (2002). Medium frog (males 27-39 mm, females 33-48 mm). Dorsal: Dorsal pattern and coloration extremely variable, but generally consisting of black and one of many colors: bright green, yellow, yellow-orange, or red. Savage (1972) has some excellent photographs showing the range of variation in patterning in this species. The dorsal surface is mostly smooth and lacks any glandular concentrations apparent in some other species of Atelopus. Ventral: Ventral surface usually yellow, sometimes mixed with green or red. Eye: Iris green. Pupil horizontal.
Breeding season: In Monteverde, Costa Rica, oviposition takes place during October-December (Savage 2002). In Sante Fe, Panama, an amplectant pair was found in June, but only non-calling males were observed in July (CoCroft et al 1990). Egg: Eggs are laid in two strings and are white (Starret 1967). Eggs are probably affixed to rocks to prevent them from flowing downstream (Starrett 1967). Eggs hatch 6 days after oviposition (Starrett 1967). Tadpole: The dark brown body is very small, rather flat and looks square from above (Savage 2002). The mouth is very large (Savage 2002). The ventral surface has a large disk that likely serves as a sucker to help tadpoles adhere to rocks in fast-moving water (Savage 2002, Duellman and Lynch 1969). An excellent illustration of the tadpole can be found in Starrett (1967). Tooth rows are 2/3 (Starrett 1967).
Habitat: Mostly found in premontane and montane forest to 2000 m but also on hills in some lowland sites. Ecology: This species is often encountered on rocks in or along the margins of streams (Crump 1986). At night, they sleep on rocks or vegetation (Crump 1986). Population declines have been documented throughout Costa Rica and parts of Panama (Pounds and Crump 1994). Adult Atelopus varius sometimes become parasitized by flies, which leads to the death of the frog (Crump and Pounds 1985). Frogs are more vulnerable to parasitism during the dry season, when they are forced to aggregate in suitable waterfall spray habitat near streams (Pounds and Crump 1987, Crump and Pounds 1989). Call: A buzz repeated numerous times (Savage 2002). Atelopus varius also produces chirps that may serve as release calls (Savage 2002). An audiospectrogram of the call can be found in Cocroft et al. (1990). Behavior and communication: Atelopus varius moves very slowly; presumably the toxins in their skin protect them from potential predators (Crump 1986). During the breeding season, males call to defend territories, but aggressive interactions may escalate to wrestling to establish dominance (Savage 2002). Females are more territorial during the non-breeding season (Savage 2002). This species exhibits homing behavior, returning to the place of capture within a week or less of displacement (Crump 1986). Karyotype: 2N = 22 (Duellman 1967, Schmid 1980) Type locality: "Veragoa". Restricted to "the Pacific portion of the Provincia Veraguas, western Panamá" by Lotters et al (1998) Physiology: The skin of Atelopus varius contains tetrodotoxin (Kim et al. 1975). Diet: Atelopus varius is an ant specialist, but feeds in small amounts on other arthropods (Toft 1981). They actively search for their prey (Toft 1981).
Diagnostic description: The dorsal background color in living specimens is lime-green, chartreuse, yellow, orange or red; lightly or heavily stained or black spots or black bars. Usually without enlarged parotid glands, but if present. Head lacking ridges. No dorsal fold in the head or fleshy fold on the roof of the mouth. Lack of well-differentiated glandular areas.
No conspicuous tarsal tubercle, and the leg lacks tarsal fold. The legs have 5 fingers. Lack two elongated internal metatarsal tubercles, like shovels, with a free margin. Without a pair of fleshy protrusions on the dorsal terminal finger region. No full digital groove on the hands or legs. The fingers have no bearing; the toes usually have bearings either.
Habitat: They live near rivers and streams and in areas containing water sifted from cataracts (presumably to reduce problems of water balance) in the humid tropical montane forest.
Territory: Research in Monteverde has generated the following information:
They have a home range of at least 10 m. (Feed him, foraging site). Both female and male maintain this level throughout the year.
Males defend territories only in the rainy season. Also few females defend territories especially in the dry season. The males have never been observed with females outside their territory, suggesting that males not only the territories used as foraging sites, but for reproductive purposes.
Females chase other females in their territory primarily during the non-breeding season. The main function is to defend aggression foraging and shelter. There is no indication that females defend spawning sites.
Some individuals that are marked are very sedentary, remaining 1-3 m. for almost 2 years. Also other travel more than 30 m. per week up and down the stream of water. Others were not observed again after the initial capture.
Reproduction: Research in Monteverde has generated the following information:
The couples begin to form in 2-5 months into the rainy season and continues a few weeks in the dry season. An estimated oviposition begins in October until early December. Toads lay eggs in water (are white and measure 35 mm.). Neither parent exhibits parental care.
The amplexus is prolonged with some pairs being held together by at least 32 days. The reproductive period defined in 4 months during which couples in amplexus down and try not to leave the females to the males, from mid-August to early December.
Behavior: They are diurnal.
Forman aggregations along the rivers in the dry season, but are distributed more evenly during the rainy season.
Relationships: Your skin has the powerful poison tetrodotoxin (neurotoxin) (viscera and muscles lack of it), what is likely the attack discourage most potential predators (vertebrates). However, the fly larva Notochaeta bufonivora (Sarcophagidae) feeds on this species and it seems that it is not affected by this chemical defense. The female lays larvae on the back surface of the thigh; They dig larvae in the thigh and feeds the muscles, before entering into the body cavity to feed on the internal organs.
All living individuals with myiasis died during the 4 days.
Molecular data: Tetrodotoxin, a neurotoxin, has been identified in the skin of the species of this genus in Costa Rica (Kim, Brown, Mosher and Fuhrman, 1975).
Distribution in Costa Rica: This species is distributed in the midlands along mountain ranges, including the Coastal Row south of the Pacific slope, between 800 and 1500 m. However, their populations disappeared in most of its distribution in Costa Rica to the early 90's. Currently, there is only one record of a population in the Cerro Nara, north of Quepos, and two populations south of the Pacific slope in the Cordillera de Talamanca.
Distribution outside Costa Rica: They are in Panama and Colombia.