The glass frogs are one of the strange but captivating creatures in the world. When you look down at this creature, you might initially notice its soft lime-green color but when you turn it over, your attention would be caught by the appearance of its abdomen. Guess what! The stomach of this creature is transparent, just like the name implies – a glass frog.
If you closely examine Glass frogs, you would visibly notice the visceral organs, including the heart, liver, gut, and lungs. You can easily observe the way its heart pumps blood throughout its body and even the way the food digests. A glass frog is also referred to as a ‘see-through frog’ because of their translucent skin. More than 120 species of glass frogs exist in about 10 genera.
Glass frogs’ habitat
Glass frogs are usually found in warm climates in Central and South America. They occur from tropical lowland forests to mid-elevation mountain forests. Most species of glass frog are small in size, with the adults ranging from 20 to 30 mm (0.8 to1.2 inches) long. In just a few species, the adults are larger, attaining a maximum length of nearly 3 inches (80 mm).
Why Glass frogs are endangered
The Northern glass frog was once the most abundant species found in Central and South America. Glass frogs are endangered sometimes due to their small size. They are an easy target for many predators, including snakes, mammals, and birds. Glass frogs are arboreal animals, as they spend most of their time on trees. They have become endangered due to habitat loss from human activities and deforestation. According to BBC, this rare species of frog was seen in Bolivia for the first time in 18 years.
Here are a few interesting facts about a glass frog:
1. They spend their lives on the trees
Spending their lives on the trees means that they are arboreal animals. They only come to the ground when it is the season for mating. As mentioned earlier, this is why they have become endangered due to habitat loss.
2. Glass frogs are hard to spot by predators
Glass frogs are usually bright green or olive green in color and are hard to spot. Because of the color – green, it is believed by some scientists that predators would find it more difficult to locate and prey on them. The translucency of the frog is a form of camouflage, which makes the edge of the frog softly blend with its surroundings. The line which separates the color of the frog’s skin from its environment is softened and this is referred to as ‘edge diffusion‘. Be it a light or a dark surface glass frogs are a pro at hiding.
3. Glass frogs are carnivorous
Glass frogs eat flesh. They eat lots of different kinds of spiders and other insects. The way glass frogs feed has not been well researched yet. But according to researchers, they appear to consume arthropods and small insects. Glass frogs have been seen hunting insects in the dense vegetation beside tropical rivers. When glass frogs are captured by scientists they are often fed fruit flies.
4. They come in different sizes
Depending on the species, glass frogs come in different sizes. Smaller species may be less than 1 inch in length, but larger species maybe about 3 inches long.
5. They are nocturnal animals
Because Glass frogs are active at night and prefer to come out at night, they are referred to as nocturnal animals.
6. Glass frogs are territorial animals
Whenever their territory tends to be occupied, the male Glass frogs alert others by vocalizing. They together ward off all the uninvited visitors. In a situation whereby this intruder refuses to leave, the males in the territory exhibit aggression and vehemently chase away the unwanted males.
7. Glass frogs have expanded digit tips that help them in climbing
The expanded digits of Glass frogs give them the ability to live in trees or shrubs along forest streams.
8. They usually mate only after the rainy season
After raining season or during the light showers, the male Glass frog hangs on a leaf above water for mating. But before the mating occurs, the male has to first call the females. Furthermore, the males who call, sit either on the streams of the topside or underside of the leaves. When the females arrive, the mating takes place on the leaf, and that is where she lays her egg. Surprising right? Female lays between 20 and 30 eggs on the underside of the leaves.
9. The male protects laid eggs
When the female Glass frog departs after laying eggs, the male has the job of protecting the eggs from predators. Some males even attract more females for mating and hence have different groups of eggs to look after. After two weeks, tadpoles hatch into the water. Pending the period for metamorphosis into froglets, tadpoles feed on leaf-litters and detritus at the streamside. One of the major egg predators is “frog flies” which lay their eggs on the egg masses. Their eggs hatch quickly, and the maggots feed on the frog embryos. Some species of glass frogs do bury themselves in the ground until they develop into adult frogs, whereas other species undergo metamorphosis in the water.
10. Glass frogs have unique pigment cells in the skin that reflects infrared radiation.
This pigmentation possessed by glass frogs provides them with camouflage property when they sit on leaves, thereby shielding them from predators, including snakes, birds, and pit vipers.
These small and rare Glass frogs have tons of supercool secrets to reveal. From the trick pattern on their skin to their see-through belly, these small and cute creatures are limited to the rainforests of Panama, Columbia, Ecuador, and Costa Rica. Around 77 species of Glass frogs are threatened with extinction due to a sudden increase in their illegal international trade. The WCS has been working for almost 10 years to conserve the habitat and the ecosystem where these unique amphibians live.
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