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Hyalinobatrachium fleischmanniRana vientre traslúcido

By Ebony Jones

Geographic Range

Mexico, Central, and South America: Northern glassfrogs occur in wet forests from southern Mexico through most of Central America to northern South America, ranging from near sea level to over 1,600m along clear, flowing, usually rocky streams (Campbell, 1998).

Habitat

This frog occurs in humid montane forests.

Physical Description

Northern glassfrogs derive their common name from the transparent skin covering their bellies, which allows some of their internal organs to be seen. The pulsating heart, covering of the lungs, and other organs can be seen through the skin of the belly of this species. They have white vocal sacs and gold irises, with an exceptionally short snout. The skin of the dorsum is smooth, having a pale lime green color with many tiny, scattered, dark melanophores and small yellow spots. Their limbs are relatively long and slender with no auxiliary membrane. Their digits have well-developed discs that are moderately expanded; their fingers are about one-half webbed and their toes are three-fourths webbed. The tops of their digits and discs are yellow.

Adults reach 22 - 25mm in SVL, males being slightly smaller than females (Campbell, 1998). In males of this family, a distinct hook or bony spine is visible. Located on the upper arm near the shoulders, it is believed that they use this hook as a weapon to defend their territory and perhaps to inflict wounds on other frogs. The hook is absent or internal in females (Badger, 1995; Campbell, 1998).

Development

Reproduction

Northern glassfrogs breed mainly during the rainy season, which extends from May to October. Clutches of eggs are laid on the under surfaces of leaves, on which they adhere, and are guarded by the males (Campbell, 1998). The yolks of recenlty laid eggs are pale green and the developing embryos are yellow. The jelly enveloping the eggs is essentially clear but with a definite green hue. The mean number of eggs varies from 18 to 30, depending on locality and time of year. There is heavy predation on the eggs by various vertebrates (e.g. Cat-eyed snake) and invertebrates (e.g. Drosophilid fly eggs), and it has been estimated that 80 percent of the clutches are destroyed before hatching.

Males of this species engage in a rather unusual form of behavior. He guards the clutch of eggs that have been deposited, and while doing this he rotates on top of them and urinates bladder water over the eggs to keep them from drying out. While guarding the eggs some of the males will eat any eggs damaged by parasites thereby controlling the spread of disease among the clutch (Badger, 1995). If all goes well their eggs should hatch 10-15 days after deposition and the tadpoles drop into the water, where they hide in submerged detritus or in loose bottom gravel. Growth in tadpoles is slow, taking at least one year, and up to two years for metamorphosis to occur (Campbell, 1998).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Behavior

Males are territorial and if one intrudes on the territory of another, a series of mew-like peeps occur, sometimes followed by four-legged push-ups and physical encounters. The advertisement call of the male is a single short, high-pitched peep. Males usually call while hanging upside down from the lower surface of leaves that hang over water (Campbell, 1998).

Food Habits

Feeding studies on this species are lacking, but (as in related small frogs) small insects, spiders, and other small invertebrates are undoubtedly eaten (Duellman and Trueb, 1994).

Economic Importance for Humans: Positive

This frog undoubtedly occupies an important insectivorous niche in its forest habitat. Glass Frogs are fascinating to study and of aesthetic value to humans.

Conservation Status

These frogs have undoubtedly lost portions of their habitat due to deforestation by humans, but precise population statistics are unavailable.

Other Comments

This frog has also been placed in the genera Centrolenella and Hyalinobatrachium by various authors. Hyalinobatrachium is used by Campbell (1998).

This account co-authored with: Kathleen Grant

Contributors

Ebony Jones (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

References

Badger, D. 1995. Frogs. Stillwater, MN: Voyageur Press, Inc..

Campbell, J. 1998. Amphibians and Reptiles of Northern Guatemala, the Yucatan, and Belize. Norman, OK: University of Oklahoma Press.

Duellman,, W., L. Trueb. 1994. Biology of Amphibians. Baltimore, MD: Johns Hopkins University Press.

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