Glass Frog

Last updated: March 14, 2023
Verified by: AZ Animals Staff
© Dirk Ercken/Shutterstock.com

You can see their internal organs.


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Glass Frog Scientific Classification

Kingdom
Animalia
Phylum
Chordata
Class
Amphibia
Order
Anura
Family
Centrolenidae

Read our Complete Guide to Classification of Animals.

Glass Frog Conservation Status

Glass Frog Locations

Glass Frog Locations

Glass Frog Facts

Main Prey
Small insects and other smaller frogs
Name Of Young
tadpoles
Group Behavior
  • Solitary/Group
Fun Fact
You can see their internal organs.
Estimated Population Size
Unknown number of thousands
Biggest Threat
Rainforest deforestation
Most Distinctive Feature
Moves by saltation (bipedal jumping)
Other Name(s)
Leaf frog, tree frog
Gestation Period
Two weeks
Litter Size
18 to 30 eggs
Habitat
Arboreal, tropical mountainous, high montane streams
Predators
Birds, snakes, and small mammals. Frog flies attack the eggs.
Diet
Carnivore
Type
Amphibian
Common Name
Glass frog
Location
Central and South America
Group
Communal

Glass Frog Physical Characteristics

Color
  • Green
Skin Type
Permeable
Lifespan
10 to 14 years
Weight
5 to 14 grams (0.2 to 0.5 ounces)
Height
1 to 2 cm (0.4 to 0.8 inches)
Length
3 to7.5 cm (1.2 to 3.0 inches)
Age of Sexual Maturity
One year
Age of Weaning
Larval tadpole stage is up to 10 months

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“If you had a living glass frog in a high school biology class, you would not have to dissect it to see its internal organs.”

Glass frogs are beautiful, exotic frog that is found in southern Mexico, Central America, and South America. Other exotic animals and fish found in this area are the caiman lizard, coati, cichlid fish, collared peccary, and the howler monkey.

Glass frogs like to live in rainforests in the mountains near flowing streams where it raises their offspring. This frog can slowly climb trees using its sticky webbed feet and jumps away from predators in one jump that may be up more than 10 feet (3 meters) long. Instead of a croaking sound, it makes a high-pitched whistling sound to attract a mate. If it survives predator attacks, it can live from 10 to 14 years.

5 Incredible Glass Frog Facts!

  • The glass frog lives high in the trees above mountainous streams during the dry season. When the rainy season comes, it climbs down to the stream level to mate.
  • The glass frog can jump more than ten feet in one jump.
  • The male frog guards the females’ fertilized eggs placed on leaves until they hatch and the tadpoles fall into the water.
  • The translucent skin of some species permits an observer to see the frog’s beating heart.
  • Glass frogs live up to 14 years.

Scientific Name

The scientific name of the glass frog is Centrolenidae. “Centro” is Spanish/Latin for “center” and “Lenidae” refers to the webbing between the toes.

The first to catalog the glass frog was an American herpetologist, Edward Harrison Taylor, who was the department head of zoology at the University of Kansas in the 1920s. Taylor made many field trips to Mexico and Central American in the 1930s and 1940s. One species of the glass frog, discovered in the Guianas, is named after him. It is the Hyalinobatrachium taylori, which is commonly called Taylor’s glass frog or “ranitas de crystal de taylor” in Spanish.

Common name: Glass Frog
Scientific Name: Centrolenidae
Subfamilies: Centroleninae, Hyalinobatrachinae
Genus: Allophryne, Celsiella, Centrolene, Chimerella, Cochranella, Espadarana, Hyalinobatrachium, Iakkogi, Incertae sedis, Nymphargus, Rukyrana, Sachatamia, Teratohyla, Vitreorana



Most beautiful animal – Fleischmann's Glass Frog

The scientific name of the glass frog is Centrolenidae. “Centro” is Spanish/Latin for “center” and “Lenidae” refers to the webbing between the toes.

©Agami Photo Agency/Shutterstock.com

Appearance

These frogs are charming and beautiful, almost magical in appearance. Glass frogs are usually tiny and can fit in the palm of the hand. The bodies are lime green on the top and transparent when viewed from underneath, revealing all their internal organs. They may also be white with a reticulated pattern of yellow spots that mimic the appearance of eggs within the female. On the back of the males, this egg pattern helps confuse predators when the males guard the fertilized eggs.

Their rarity and loveliness are enhanced because they are hard to see and even harder to capture. Biologists, who study them in the tropical rainforests, are still discovering new species.

The translucent skin on their belly allows them to rest with legs next to their body and softens the brightness of the edges, making the frog’s outline less noticeable. This gives them a bit of camouflage with less visibility to birds that might be attracted to swoop down and eat them. During the rainy season, when they come down from the trees for mating, it is possible to see the eggs within the females’ body before she lays them for the male to fertilize.

They have big, bulbous, golden-green eyes with black pupils. Their eyes face forward from the top of their heads and rotate independently. They have excellent eyesight, which helps them catch insects to eat.

amphibian

Though its transparent skin is a bit spooky, the bare-hearted glass frog looks a lot like Kermit the Frog!

©Dirk Ercken/Shutterstock.com

History and Evolution

You might wonder why being see-through would be an advantage that was developed as this frog species evolved over time. Many have also wondered the same thing since they were discovered by modern science.

As amazing as this feature is, it does help the glass frogs to blend into their surroundings. Their bodies play tricks on would-be predators to where they see the environment behind the glass frogs. This only occurs to a certain point. These frogs are actually more translucent than transparent.

As an evolutionary advantage, glass frogs are even more hidden in their moist environments and especially in water, where they tend to deposit eggs and thrive.

Types of Glass Frogs

There are many types of glass frogs in the world. Here are just a few of them!

  • Centrolene antioquiensis – This glass frog is also called Antioquia giant glass frog and can be found in central Colombia at high elevations.
  • Centrolene ballux – Also known as the golden-flecked glass frog, they are found in Ecuador and Columbia at elevations of 5,000 – 8,000 feet
  • Centrolene buckleyi – This frog draws its name from Samuel Botsford Buckley, a naturalist. They can be found in South America, specifically in Peru, Comumbia, and Ecuador and in moist forests.
  • Centrolene heloderma – Also known as the bumpy glass frog, these amphibians are in the cloud forests of Columbia and Ecuador. At 1.0 to 1.3 inches long, they are one of the larger subspecies of the glassfrog.
  • Centrolene lynchi – These frogs are also called Lynch’s giant glass frog after the first person to collect this particular frog. Dispite their common name, they are not one of the bigger glassfrogs. They can be found in Ecuador.
  • Centrolene sanchezi – These glass frogs can be found in tropical montane forests of Columbia and Ecuador. They are known for using high-pitched clicking sounds.
  • Centrolene notosticta – Also known as the cordillera giant glass frog, these tiny amphibians can be found in Venezuela and Columbia. Its numbers in the wild are not as threatened as some of its cousins.
  • Centrolene savagei – These frogs are also called Savage’s Cochran frog and can be found in the Columbian Andes.

Behavior

Glass frogs are nocturnal. They are communal and live in small groups. A group of frogs is called an “army. They hunt for food from dusk until sunrise. When the sun comes up, they find a place to hide in the trees under the leaves in the upper canopy. They sleep all day until it becomes dark again. They almost disappear when hiding in the trees.

They stay high up in the trees during the dry season, far away from any land-based predators. They only come down when it rains.

Habitat

The glass frogs live in the tropical lowland forest and the mid-elevation mountain forests in Mexico, Central America, and South America. They live in forested areas near mountain streams, which they need to raise their young.

Glass frogs can be found in southern Mexico and in the areas set aside for protecting biodiversity all the way south to Panama, where they are not forced to make any significant adaptations due to human activity. They are commonly found in the rainforests of Colombia, Costa Rica, and Ecuador.

They live in the Andes in Venezuela and on the island of Tobago. They are found in Bolivia. Some species live near the Amazon and Orinoco rivers, the Guiana Shield region, southeastern Brazil, and the northern part of Argentina.

During the dry season, they live up high in the trees. The dry season is usually from late November to April. It may start to rain a little in May, which is the beginning of the wet season. The heaviest rains are usually from mid-August to November. During this time, the glass frogs have their mating season.

Glass frogs are sometimes kept as pets but require specific care needs. As such, they should not be kept by beginner hobbyists.

Tropical glass frog from Amazon rain forest, Hyalinobatrachium Iaspidiense

Glass frogs live in the tropical lowland and mid-elevation mountain forests in Mexico, Central America, and South America.

©Dirk Ercken/Shutterstock.com

Predators and Threats

Humans’ constant encroachment with the destruction of the rainforest is the greatest threat to the destruction of the glass frogs’ habitat. Human poachers try to catch them from protected rainforest areas to sell them as part of the illegal rare animal trade to collectors.

The Glass Frog Conservation Status: About one-third of the species of glass frogs are stable, with two-thirds decreasing. Up to 36 species are threatened at different levels of endangerment. They all have protected status in their countries of origin.

What Eats Them?

The biggest natural threats to adult glass frogs in the wild are other animals and snakes that climb into the trees where they live. They are also vulnerable to being eaten by birds. When they are closer to the forest floor during the mating season, they are vulnerable to being eaten by lizards and various small mammals.

Glass frog eggs are a tasty snack for wasps and the offspring of frog flies. The frog flies lay their eggs on the clutch of the frog’s eggs. When the fly eggs hatch, the maggots eat the embryos of the frogs. The male glass frog guards the eggs against these predators. When an attacking wasp flies up and tries to eat a frog egg, the male glass frog kicks the wasp away in a quick sweeping move that sends the wasp flying into the nearby forest.

When they are young tadpoles living in water, glass frog tadpoles are vulnerable to being eaten by fish, birds, beetles, and even dragonfly larvae.

What Do They Eat?

Glass frogs are carnivores. They like to eat small insects that they can catch. This includes spiders, ants, crickets, moths, flies, and tiny bugs that crawl along the tree branches. They may also occasionally eat other smaller tree frogs.

Their hunting style is to stay still and wait. They let their prey crawl up until it gets in range and then strike out with their tongue to gobble the insect up.

Ghost Glass Frog (Sachatamia ilex) with amazing eyes

Glass frogs are carnivores and like to eat small insects that they can catch.

©G.J. Verspui/Shutterstock.com

Reproduction and Life Cycle

When the rain comes, this triggers the mating season. As soon as the forest is wet enough, the males descend to hang out on a large tree leaf just above a flowing stream. They make a high-pitched whistle that calls to the females. A female, attracted by the sound, descends to the laying leaf when she is ovulating.

The male mounts her back and waits patiently in rapture until the female lays her eggs on the leaf. After the female expels her eggs all at once, the male fertilizes them. She may lay up to 30 eggs, called a clutch, which flows out of her all at once covered with a clear substance like a liquid glue to hold them safely in place on the leaf.

When her eggs are out, she goes back up into the trees. She leaves the male behind. He guards the eggs for the gestation period of up to two weeks. The males become territorial during the mating season. They will wrestle with other males to be able to fertilize the female eggs. Once on guard protecting a clutch of eggs, the males will whistle again to call other females to lay more eggs. A male may guard as many clutches of eggs as will fit on the large laying leaf.

When the tadpole embryos are large enough, they break out of the eggs and fall off the leaf into the water below. The tadpoles reside in the bottom of the stream, living among the detritus on the bottom for up to ten months until they grow into adult frogs. The ones that survive to adulthood climb back out of the water. They climb back up into the trees to join the rest of the glass-frog family waiting for them.

One of the most interesting facts is that glass frogs have the potential for long life. They may live for 10 to 14 years if they avoid being eaten by predators and can make adaptations if any climate changes require them.

Weirdest Animal: Glass frog

The translucent skin of some species permits an observer to see the frog’s beating heart and eggs.

©petrdd/Shutterstock.com

Population

The sad facts are, there is an unknown number of glass frogs remaining. Up to 36 species are endangered. There is a movement in Costa Rica and elsewhere to protect their habitat. Species are being lost as the rain forests are cut down to make way for human agricultural activities. Cutting down the jungle destroys the habitat of the glass frogs. They are not able to make the adaptations necessary to survive this human onslaught.

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About the Author

Heather Ross is a secondary English teacher and mother of 2 humans, 2 tuxedo cats, and a golden doodle. In between taking the kids to soccer practice and grading papers, she enjoys reading and writing about all the animals!

Glass Frog FAQs (Frequently Asked Questions) 

What is a glass frog?

A glass frog is a small amphibian found mostly in the Central and South American rain forests.

Why are these frogs called glass frogs?

Glass frogs are called this because of their translucent nature that allows an observer to look into their bodies as if their skin was made of glass.

What do glass frogs eat?

They will eat any insect or smaller frog that comes close enough to be gobbled up by them as their next meal.

Where does a glass frog live?

Most of the time, they live in the tree canopy in the lush rain forest, high above the ground. However, when it is mating time, they come down to mate. The female lays eggs on a big leaf hanging over a stream where the male fertilizes them. Then, the male stands guard until the eggs hatch.

Can you have a glass frog as a pet?

Yes, but they are endangered and therefore difficult to obtain legally and very expensive. Some are raised in captivity as a pet. They sell for up to $1,000 for a male and a female for breeding purposes. They are excellent pets but do require the proper conditions in a terrarium. They have a voracious appetite and need to eat a lot of live bugs.

Are glass frogs poisonous?

They are not poisonous at all. They are very gentle and harmless.

How do Glass Frogs have babies?

Glass Frogs lay eggs.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.

Sources
  1. Britannica, Available here: https://www.britannica.com/animal/glass-frog
  2. Animals, Available here: https://animals.jrank.org/pages/163/Glass-Frogs-Centrolenidae-BEHAVIOR-REPRODUCTION.html
  3. Research Gate, Available here: https://www.researchgate.net/publication/323702843_Community_assembly_of_glass_frogs_Centrolenidae_in_a_Neotropical_wet_forest_a_test_of_the_river_zonation_hypothesis
  4. Rainforest Alliance, Available here: https://www.rainforest-alliance.org/species/northern-glass-frog
  5. PNAS, Available here: https://www.pnas.org/content/117/23/12885
  6. Protection of Glass Frogs, Available here: https://defenders.org/sites/default/files/2019-08/glass-frogs.pdf
  7. Animal Diversity Web, Available here: https://animaldiversity.org/accounts/Centrolenidae/
  8. Wikipedia, Available here: https://en.wikipedia.org/wiki/Glass_frog
  9. EOL, Available here: https://eol.org/pages/39866
  10. National Geographic Kids, Available here: https://kids.nationalgeographic.com/animals/amphibians/reticulatedglassfrog/
  11. All About Frogs, Available here: http://allaboutfrogs.org/weird/general/numbers.html

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