Chile Four Eyed Frog

Pleurodema thaul is a small frog with a maximum SVL of 50 mm. Females are larger than males (Diaz-Paez and Ortiz 2001). Cei (1980) describes this species as follows: "The skin is smooth, with sparsely distributed flat warts on the back. Its head is slightly wider than large, with a rounded snout and prominent laterally located eyes. Nostrils are dorsally located, midway between the eye and the tip of the snout. The canthus rostralis is nearly indistinct and the loreal region slants gently to the upper lip. The tympanum is small, and somewhat indistinct. There is a moderate supratympanic fold. Lumbar glands reach to about 1/8 of the body length. The fingers are almost free, with fringes, and the relative finger lengths are 2=4

Note: Pleurodema thaul is native only to Chile and Argentina. Pleurodema thaul occurs up to 2100 m above sea level (IUCN 2004). In Chile, the northern end of this frog's range is found near Antofagasta, in the northern arid territories, with a disjunct distribution mainly near rivers such as the Copiapo and Huasco (Duellman and Veloso 1977). It occurs down to the southern Nothofagus forest of the Aysen Region of Chile (Duellman and Veloso 1977). This species has a wide east-west distribution, from sea level up to the vegetation line of the western slopes of the Central Chilean Andes range (IUCN 2004). Pleurodema thaul is also found in the Andean-Antarctic region (Argentina), from Laguna Superior de Epulafquen, Departamento Minas (Neuquen) south to the area between La Plata and Chico lakes, Departamento Rio Senguer (Chubut) (Ubeda 2001). It is absent in the Patagonian steppe where it is substituted by Pleurodema bufonina (Cei 1980). Pleurodema thaul is generally found in Nothofagus forest. Other habitats include grassland, steppe, and transitional zones, as well as urban and disturbed areas. Adults are found below logs and rocks and within vegetation. Reproduction occurs preferentially in shallow ponds, producing free-swimming larvae, though any type of water body may be used. (IUCN 2004). Pleurodema thaul also occurs in Araucaria forests in southern Chile and Argentina (Duellman and Veloso 1977).

Pleurodema thaul does not appear to be threatened, as it is abundant and ecologically versatile, tolerating a broad range of habitats. Individual populations may be affected by factors such as habitat burning, water pollution, and drought (IUCN 2004).

The breeding period begins between June and August, and continues until December (Diaz-Paez and Ortiz 2001). The reproductive cycle of P. thaul is almost continuous, with gametogenetic activity in males and females during the fall, winter, and spring of the southern hemisphere (Diaz-Paez and Ortiz 2001). As in other species of temperate regions, changes in temperature are the main influence on reproduction, followed by changes in rainfall (Diaz-Paez and Ortiz 2001). Eggs are deposited in strings or gelatinous masses in water, among the aquatic plants filling the lagoons (Cei 1980; Duellman and Veloso 1977). Any body of water may be used, but shallow ponds are preferred. The mating call of P. thaul is metallic and variable (Cei 1980). Males call from the water surface in marshes, where sound propagation is better than in bogs (Penna and Solis 1998). Duellman and Veloso (1977) stated that the call consists of a modulated trill having a duration of 0.2 to 9.0 seconds, and that the second (of five) harmonic at about 1500-2300 Hz is dominant. The fourth harmonic at about 5900 Hz is also emphasized (Duellman and Veloso 1977). The short call durations given above are for single individuals. In contrast, males calling in large choruses sometimes call continuously for nearly one minute (Duellman and Veloso 1977). Duellman and Veloso (1977) also reported that a group of four males was observed to have an initially organized chorus structure. One male emitted short, loud, poorly modulated notes followed by the usual mating call. These two kinds of calls had different harmonic structures. As soon as the trill began, the other individuals began trilling (Duellman and Veloso 1977). This frog's diet consists mostly of a diverse selection of arthropods, with arachnids and dipterids the most common prey, but also includes a small amount of vegetation (Diaz-Paez and Ortiz 2003).

Despite human-induced habitat loss and degradation, Pleurodema thaul appears to thrive in the following artificial habitats: pastureland, plantations; ponds water storage areas, irrigation channels, wastewater treatment areas, open excavations, and irrigated/seasonally flooded agricultural land. It has also adapted to introduced vegetation (IUCN 2004).

Brasil

LC. Least Concern.

Marov

Adult morphology Snout-vent up to 50 mm in the largest specimens. Head ogival, slightly wider than larger; snout rounded, larger than diameter. Nostrils dorsal] located, at midway between eye and tip of snout. Interocular distance smaller than. The internarial interval and the upper eyelid. Canthus rostralis almost indistinct; loreal region gently slanding ro the upper lip. Maxillary teeth weak; vomerine teeth in two strong spaced patches between the choanae. Eye prominent, laterally located. Tongue subcircular, notched behind. Tympanum small, slightly indistinct; its diameter less than 1/2 of the eye diameter. Supratympanic fold moderate, reaching before the axilla. Fingers almost free, fringes wident; rate of the finger lengths: II=IV-I-III. Subarticular tubercles blunt and prominent as well as the metacarpal or palmar tubercles. Toes slightly webbed and distinctly fringed; subarticular tubercles sharply conical. Metatarsal tubercles rounded and prominent. Tarsal fold present. When hindleg is adpressed, heel reaches the eye; when the femurs are bent at right angles to body, the tibio-tarsal articulations touch. Skin smooth and porous, with scanty glandular flat warts on the back. Lumbar glands about 1 1/2 time the eye diameter, or about 1/8 of the body length. Discoidal fold present. Grayish nuptial pads in males. Dorsally yellowish, greenish or dark green, scattered with bright symmetrical brown spots. A bright central black spot on the inguinal gland. Ventrally whitish or yellowish, immaculate. Larval morphology The body is grayish, wide and rounded, with a very short tail, scantily spotted above. The spiracle is sinistral, lateroventrally located; the anal opening also almost sinistrally oriented. The interocular distance is larger than the internarial inteval. The mouth is characterized by broad lateral folds, bordered by variable series of papillae. The horny beaks are strong and wide; the tooth rows formula is usually 2(1)/3(1).

sementes viáveis

resinas

perene

trepadeira

Inhabit both hillsides of the Andes in southern South America.In Argentina inhabits Â?Bosques patagónicosÂ? ecoregion, and also there are a few reports at Â?Estepa patagónicaÂ? ecoregion. Furthermore, the currently known distribution of this species comprises almost the entire territory of Chile, from localities in Atacama desert (Region III) (Copiapo, Vallenar, and Pajonales), to Aysén (Region XI), from sea level up to 2700 m a.s.l. in Vega Piuquenes locality, occurring at Â?DesérticaÂ?, Â?CentralÂ?, and Â?SubantárticaÂ? or Â?ValdivianaÂ? biogeographic regions of Chile. The altitudinal record of this species in Chile (2727 m a.s.l.), far exceeds the altitudinal range reached by the species in Argentina.

Diagnosis A slender, ranoid Pleurodema, brightly colored and spotted, with tympanum inconspicuous and prominent rounded lumbar glands. Snout rounden, not truncated; nostrils not terminal, no evident bulky gland on the mouth joint; lumbar glands 1/6 of the body length or less; bright irregular spots on the dorsum; short longitudinal gland but no W-shaped glandular ridge on the shoulder.

Pleurodema thaul, the Chilean four-eyed frog is a species of frog in the family Leptodactylidae. It is found in Argentina and Chile. Its natural habitats are subantarctic forests, temperate forests, temperate shrubland, temperate grassland, rivers, intermittent rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, pastureland, plantations, rural gardens, urban areas, water storage areas, ponds, open excavations, sewage treatment areas, irrigated land, seasonally flooded agricultural land, and introduced vegetation. It is threatened by habitat loss.

Individuals vary in size between 3 and 5 cm. They feed on insects and spiders. Reproduction occurs almost throughout the year. In Chile they are found from the Antofagasta region to the Aysén Region, while in Argentina they live in areas close to the Andes in the provinces of Neuquén, Rio Negro, and Chubut.