Academic literature on the topic 'Glass frogs (Amphibians)'

The glass frog Vitreorana uranoscopa (Müller, 1924) has been considered a vulnerable species for the state of Rio Grande do Sul, southern Brazil. This note recorded the presence of the species for São Marcos municipality, extending the species distribution towards eastern region of the state.

A new diminutive species of microhylid frog (genus Microhyla) is described from the Matang Range, Sarawak, Malaysian Borneo. The new species is an obligate of the pitcher plant, Nepenthes ampullaria, breeding in senescent or mature pitchers, and is Old World’s smallest frog and one of the world's tiniest: adult males range between SVL 10.6– 12.8 mm (n = 8). The new species is diagnosable from congeners in showing dorsum with low tubercles that are relatively more distinct on flanks; a weak, broken, mid-vertebral ridge, starting from forehead and continuing along body; no dermal fold across forehead; tympanic membrane and tympanic annulus absent; Finger I reduced to a nub proximal to Finger II in males; toe tips weakly dilated; phalanges with longitudinal grooves, forming two scale-like structures; webbing on toe IV basal; toes with narrow dermal fringes; inner and outer metatarsal tubercles present; and dorsum brown with an hour-glass shaped mark on scapular region. Miniaturization and reduced webbing may be the result of navigation on the slippery zone of pitchers, situated below the peristome.

We investigated the impact of dipteran predators on eggs in foam nests of the Common Hour-glass Tree Frog Polypedates cruciger Blyth, 1852 (Anura: Rhacophoridae) in central Sri Lanka. Foam nests (n=24) of P. cruciger were examined at their natural breeding habitats and infected (n=8) and uninfected spawns (n=16) were identified. Emerging tadpoles were collected in a water container hung under each spawn and the average number of tadpoles (N) hatched from infected spawns (N=0) was compared with that of uninfected spawns (N=354 ± 67). Three severely infected spawns were brought to the laboratory and the fly larvae were reared until they metamorphosed to adults. Morphological and molecular identification of the flies confirmed them as belonging to Caiusa testacea Senior-White, 1923 of the family Calliphoridae. The infected spawns were completely destroyed and an estimated average of 400 P. cruciger eggs per spawn were lost. The results revealed a high impact of Caiusa testacea on egg and embryo mortality of P. cruciger.

The adaptive role of amphibian oocyte melanic pigmentation and its molecular control are still elusive. Here we present evidence of a polymorphism in egg pigmentation in the emerald glass frog Espadarana prosoblepon. In Ecuadorian natural populations of this species, females can lay dark brown or pale eggs that develop into normal pigmented tadpoles and adults. This trait is a sex-limited phenotype that is inherited like a recessive allele that we called pale eggs like (pel). The pel phenotype is exclusive of oocyte cortical melanic pigmentation, which is reduced in comparison to wild type (wt) dark pigmented oocytes. Consequently, pel early embryos are paler in appearance, with reduced melanic pigmentation distributed to early blastomeres and embryonic ectoderm. However, these embryos form normal melanocyte derived pigmentation. Finally, we discuss the origin of this polymorphism and propose the use of E. prosoblepon as a model to study the adaptive role of egg pigmentation.

Anyone who stood on the bridge over the Río Guacimal at Monteverde on a wet-season night in the early 1980s would understand Archie Carr’s sentiments. Nearly 300 male Fleischmann’s Glass Frogs (Hyalinobatrachium fleischmanni) defended territories along a 120-m section of the stream, and their loud, incessant “peeps” filled the air. In the late 1980s, however, this chorus all but fell silent as the number of glass frogs plummeted. The population has not recovered. In 1998, only a single male could be heard from the bridge. The dramatic reduction in glass frogs was part of a larger decline of Monteverde’s amphibians. A sudden crash of populations in 1987 affected species throughout the area and led to the disappearance of many (Pounds 1990, 1991a, 1997, Crump et al. 1992, Pounds and Crump 1994, Pounds and Fogden 1996, Pounds et al. 1997). The disappearance that has drawn the most attention, however, is that of the Golden Toad (Bufo periglenes). This species, known only from elfin cloud forest high on the ridgetops at Monteverde, is famous for its striking appearance and the colorful spectacle of its breeding congregations (Savage 1966, Jacobson 1983, Fogden and Fogden 1984, Jacobson and Vandenberg 1991; see Savage, “Discovery of the Golden Toad,”. Because the Golden Toad had been locally abundant in seemingly undisturbed habitats for at least 17 consecutive years, its sudden disappearance caused great alarm and dismay (Pounds et al. 1997). Interest in this case has intensified with the suggestion that it is part of a global pattern (Barinaga 1990, Blaustein and Wake 1990, 1995, Phillips 1990, 1994, Wyman 1990, Wake 1991, Wake and Morowitz 1991, Sarkar 1996; see Pounds, “Monteverde Salamanders,”). Many similar declines and disappearances have been reported for highland areas of other continents (Corn and Fogleman 1984, Heyer et al. 1988, Osborne 1989, Weygoldt 1989, Czechura and Ingram 1990, La Marca and Reinthaler 1991, Carey 1993, Fellers and Drost 1993, Kagarise Sherman and Morton 1993, Drost and Fellers 1996, Laurance et al.