Toads: habitat, food and curiosities
Toads are small amphibious animals belonging to the Order Anura.
The Order of the Anurans covers another 5000 species of frogs, frogs and pererects. The frogs belong to the family Bufonidae, with about 454 species. In Brazil, most species are found in the Atlantic Forest and the Amazon.
The life of frogs is closely related to water. Water is fundamental for their reproduction and humidity ensures skin respiration.
The Bufo marinus (toad) is the most common species in Brazil.
Toads' skin is dry, glandular and vascularised. They do not have any type of hair or scales.
The thin skin allows gas exchange, skin breathing. This condition also imposes that frogs inhabit humid and shaded environments. Exposure to the sun's rays can cause the skin to dry out. Therefore, many frogs are only active at night.
The colouring of frogs can be similar to where they live, which is important for their defence. Other species can be coloured and are very attractive.
Frogs can also find chemicals in their skin that act as a defence against predators, fungi and bacteria.
Toads can be found all over the world except in very cold places.
In general, frogs live in humid places, such as near streams, lagoons, streams and wetlands. This is because their way of life is strongly related to water.
Toads have two life stages:
The larval phase, in an aquatic environment, when they perform gill breathing. And the adult phase, in a terrestrial environment, when they perform lung and skin respiration.
Toads feed on spiders, beetles, locusts, flies, ants and termites. Some larger species may eat small birds and even other frogs.
The frog captures its prey through its tongue, which is very agile and extensible. The tongue is still sticky and makes the food stick until it is taken inside the mouth.
A curious fact is that the frog closes its eyes to swallow the food. This is because the large eyes are forced into the mouth cavity and help to push the food down the throat.
The reproduction of frogs starts when the males coach (sing) to attract the females. In some species, the female chooses the male with the strongest singing. The singing guides the female to the meeting with her partner. Generally, the male sings close to the water environment, necessary for reproduction.
When they are together, the male hugs the female, an act called amplexo, and the gametes are released into the water. In this case, the frogs perform external fertilization.
Learn more about Internal and External Fertilization.
After a while, the eggs release the tadpoles (larval phase), which undergo metamorphosis and become adults in miniature, reaching the terrestrial environment. The time of metamorphosis varies from species to species, can take from days to months.
The main characteristic of frog metamorphosis is the loss of tadpoles' tails, which turn into legs. This condition allowed the advance to the terrestrial environment and was an important evolutionary achievement.
Learn more about the Metamorphosis of Animals.
Some species of frogs are poisonous. Learn about some of these species:
- Dendrobates leucomelas: Species found among trees and rocks. The poison is located under its skin.
- Phyllomedusa bicolor: A very poisonous species found in the Amazon. In humans, the poison can cause tachycardia, vomiting and diarrhea.
- Phyllobates terribilis: One of the most poisonous frogs in the world, although it is only 5 cm long. Found in Colombia.
- Phyllobates bicolor: Native to Colombia. Its poison was once responsible for the death of humans.
- An adult frog eats approximately the equivalent of 3 cups full of flies per day.
- Frog and frog songs are genetically inherited from one generation to the next, and do not require learning.
- Because frogs produce chemicals on the skin that protect them against bacteria and fungi, there is less chance of acquiring a disease when we touch a frog than when we touch dogs or cats, for example.