This strange frog species has a snake-like appearance, causing many to feel frightened upon their first encounter.
When people think of frogs, they often picture the amphibians with smooth, moist skin, long powerful hind legs, and impressive jumping abilities. However, there exists a frog species with an unusual appearance that resembles a snake more than a frog, which can be quite alarming for those who see it for the first time.
The Frog with a Snake-like Appearance
The frog referred to here is the caecilian frog, scientifically named Ichthyophiidae. This species has many different subspecies, and several of them are currently threatened or on the verge of extinction due to declining populations.
If ten people were to encounter this creature, seven would likely mistake it for a worm, while three might think it is a snake. In reality, this animal belongs to the family of… frogs.
This species belongs to the amphibian family and is distributed across various mountainous regions of Vietnam, stretching from Thái Nguyên to Cà Mau.
The caecilian frog is the only limbless amphibian species found in Vietnam. It has a long body with smooth, shiny skin, numerous transverse folds along its body, and no limbs, giving it a striking resemblance to a snake, which can frighten many when they first encounter this animal.
The movement of caecilian frogs is also snake-like, as they wriggle their bodies to move forward. Their appearance allows them to adapt to a subterranean lifestyle, often found beneath leaf litter, enabling them to easily navigate through soil crevices and tunnels.
Below are some images of this fascinating creature:
The caecilian frog’s body resembles that of a large earthworm. (Photo: Phùng Mỹ Trung).
Furthermore, the caecilian frog’s sleek body with shiny brown-yellow stripes and its flat head further evoke images of brightly colored venomous snakes. (Photo: War/Nguyễn Vũ Khôi)
The body length of caecilian frogs can reach several tens of centimeters. (Photo: pskhun)
They differ from worms in that their head features small eyes like two black dots. (Photo: Maxim Ryzhov)
The caecilian frog has a small, slightly flattened head with a relatively sharp snout and visible jaws. (Photo: biozcw)
In the tadpole stage, caecilian frogs have gills on either side of their necks. As adults, the gills disappear, and the animals breathe differently.
Caecilian frogs typically inhabit high-altitude areas such as the Tam Dao range, but they are also found in lowland regions like U Minh forest. (Photo: Maxim Ryzhov)
Living underground like worms, their nests are often found in loose soil approximately 20-30 cm deep near ponds. (Photo: eol.org)
The diet of caecilian frogs consists of earthworms and some types of insects. (Photo: thetexanherper.com)
The population of caecilian frogs is currently quite low due to habitat loss in many areas. (Photo: Nikolai Orlov)
They lay eggs near water. Each clutch contains about 20 eggs connected by a gelatinous substance, and the female wraps around them to protect them from drying out while regulating the temperature for optimal development of the embryos. (Photo: thetexanherper.com)
This unique amphibian has been included in Vietnam’s Red Data Book and is protected by law. (Photo: Pskhun)
The caecilian frog has an indistinct head and body. Its eyes and mouth are very small and hard to see. Located at the front of the caecilian frog are two short tentacles near the eyes, which help it sense its surroundings and search for food.
The caecilian frog’s diet consists of earthworms, insect larvae, caterpillars, and spiders. Thus, caecilian frogs play a crucial role in controlling insect populations and maintaining ecological balance in their habitats.
Caecilian Frogs – Exceptional Mothers in the Amphibian World
While most amphibian species like frogs, toads, and others often abandon their eggs after laying, caecilian frogs exhibit a high level of care for their eggs.
During the breeding season, female caecilian frogs seek moist, water-adjacent locations to lay their eggs. After laying, the female wraps around the eggs to protect them, secreting a gelatinous substance to prevent them from drying out. The mother also regulates the temperature and humidity for the eggs, ensuring the highest possible hatching success rate.
Are Caecilian Frogs Venomous?
Caecilian frogs possess small mouths, containing two teeth that allow them to hunt prey.
Initially, scientists believed caecilian frogs were non-venomous. However, recent studies have discovered that caecilian frogs have venom glands in their mouths and can secrete venom when biting.
The caecilian frog has a small mouth, making it nearly incapable of biting or attacking humans (Photo: Flickr).
Nevertheless, as of now, scientists are still unable to fully understand how the toxic properties of the worm frog affect humans. Additionally, due to the small mouths of worm frogs, they find it very difficult to bite and inject venom into humans.
Worm Frogs – A Protected Species in Vietnam
In Southeast Asia, 11 species of worm frogs have been documented, with 4 species found in Vietnam, of which 3 are endemic. The species of worm frogs identified in Vietnam include:
Cat Loc Worm Frog (Scientific Name: Ichthyophis catlocensis): This species was first discovered in 2015, in the Cat Loc area, part of Cat Tien National Park (located in both Cat Tien and Bao Loc districts, Lam Dong).
A close-up of a Cat Loc worm frog, photographed at Cat Tien National Park, Lam Dong Province (Photo: E.A. Galoyan).
The Cat Loc worm frog does not have the long yellow stripe along the body typical of other worm frog subspecies. This species is small, reaching only about 20cm in length when fully grown.
This worm frog is very rare, to the point that scientists have yet to record its biological characteristics such as reproductive behavior, habitat, and diet…
Cha Lo Worm Frog (Scientific Name: Ichthyophis chaloensis): This worm frog has a solid dark green color and also lacks the long yellow stripe commonly found on other species. When fully grown, this species reaches approximately 22cm in length.
A close-up of a Cha Lo worm frog, photographed at Phong Nha – Ke Bang National Park, Quang Binh Province (Photo: Nguyen Quang Truong).
The Cha Lo worm frog was first discovered in 2015 at Phong Nha – Ke Bang National Park, Quang Binh. This species is currently only recorded in Cha Lo hamlet, Hoa Son commune, Minh Hoa district, Quang Binh, at an elevation of over 600m.
Similar to the Cat Loc worm frog, the Cha Lo worm frog is also very rare, making it difficult to fully document its biological characteristics.
Nguyen Worm Frog (Scientific Name: Ichthyophis nguyenorum): This species was discovered in 2012 in the Kon Tum Plateau in Central Vietnam. The name Nguyen worm frog honors two Vietnamese researchers of reptiles and amphibians, Nguyen Quang Truong and Nguyen Thien Tao.
A close-up of a Nguyen worm frog, notable for its two yellow stripes running along its body (Photo: Chris Joldnall).
This worm frog is endemic to Vietnam and is found in the Central Highlands and southern provinces, including Lam Dong, Gia Lai, Kon Tum, Dong Nai, and Binh Phuoc.
This species has a dark purple-black dorsal surface, a lighter underbelly, and continuous yellow stripes on both sides, extending from the upper jaw to near the tail tip. The adult body can reach 30cm in length.
The Nguyen worm frog is often spotted during heavy rains. They usually inhabit damp areas under forest canopies, muddy edges of streams, and are sometimes found in coffee plantations, rice fields, or residential areas.
Koh Tao Worm Frog (Scientific Name: Ichthyophis kohtaoensis): This species features two evenly spaced yellow stripes running from the eyes to the tail tip, with a brown dorsal surface and a lighter brown underbelly. When fully grown, this worm frog can reach about 40cm in length.
This species is named after Koh Tao Island in Thailand, where it was first discovered in 1960. Apart from Thailand, it is also widely distributed from southern China, Vietnam, Laos, and Cambodia.
In Vietnam, the Koh Tao worm frog has been found in Phu Tho, Tien Giang, An Giang, and Ca Mau provinces, but only in very small numbers.
The Koh Tao worm frog resembles the Nguyen worm frog but is larger in size (Photo: iNaturalist).
The Koh Tao worm frog is found in damp areas under forest canopies, in coffee plantations, rice fields, or forest-edge residential areas. This species is most active during the rainy season and is often seen after heavy rains.
The worm frog species in Vietnam currently face habitat loss and food shortages due to deforestation, soil erosion, and prolonged flooding, which can cause them to suffocate in the soil… These species have now been included in the Red Book of Vietnam, requiring conservation and a ban on hunting.
It is hoped that the information provided in this article will help readers distinguish between worm frogs and snakes, thereby preventing the accidental killing of these rare and declining species.
