Difference Between Urodela Anura and Apoda

The key difference between Urodela Anura and Apoda is that amphibians belonging to Urodela have a long tail and two pairs of limbs of about equal size while amphibians belonging to Anura have long hind limbs and are tailless. Meanwhile, the amphibians belonging to Apoda lack limbs.

Amphibians are a group of vertebrates. They can live in both aquatic and terrestrial environments. This group includes organisms like frogs, salamander, toads, caecilians and newts. They are ectothermic tetrapods. Amphibians can breathe through their skin as well as absorb water through the skin. There are three major taxa in this group: Urodela, Anura and Apoda. These three groups vary in their sizes and structures.

CONTENTS

1. Overview and Key Difference
2. What is Urodela
3. What is Anura 
4. What is Apoda
5. Similarities Between Urodela Anura and Apoda
6. Side by Side Comparison – Urodela vs Anura vs Apoda in Tabular Form
7. Summary

What is Urodela?

Urodela is a taxon of amphibians which include salamanders. Amphibians of this tax have a long tail. They also have two pairs of limbs of about equal size. Some species of salamanders have lungs while some species have gills. Salamanders live in moist, dark places such as under rocks, leaves and logs. They are most abundant in cool, moist, montane forests. Moreover, salamanders rely on internal fertilization.

What is Anura?

Anura is a taxon of amphibians that includes frogs and toads. These amphibians have long hind limbs. Moreover, they do not have a tail. These two features distinguish them from the other two groups of amphibians.

Frogs have longer legs, and skin covered with mucus. They have the ability to climb trees with sticky pads on their feet. In contrast, toads usually live on the ground. They have a wart covered skin and shorter legs. Frogs and toads have five to nine presacral vertebrae. They lack functional lungs.

What is Apoda?

Apoda is the third group of amphibians. This group includes caecilians, which are limbless amphibians. They are long and slender organisms. Their appearance resembles the appearance of earthworm.  Their body is segmented by annular grooves. They also have a short blunt tail.

Amphibians belonging to Apoda are found in swampy places. They eat insect larvae, termites and earthworms. Therefore, they are carnivorous. Caecilians can breathe through their skin as well as through the lungs.

What are the Similarities Between Urodela Anura and Apoda?

• Urodela Anura and Apoda are three major groups of amphibians.
• They live in and out of water.
• They have a tetrapod body.
• Moreover, they show external fertilization.
• They have a moist, permeable skin used for cutaneous respiration.

What is the Difference Between Urodela Anura and Apoda?

Urodela is a taxon of amphibians that includes species with a long tail and two pair of limbs of equal size. Meanwhile, the Anura is a taxon of amphibians that includes species with long hind limbs without a tail. Whereas, the Apoda is the third taxon that includes species which are limbless. So, this is the key difference between Urodela Anura and Apoda.

The below infographic tabulates the differences between Urodela Anura and Apoda in more detail.

Summary – Urodela Anura vs Apoda

Urodela, Anura and Apoda are the three groups of amphibians. Urodela amphibians have a long tail and two pairs of limbs which in equal size. Anura amphibians are tailless and have long hind limbs. Apoda amphibians have a short blunt tail, and they are limbless. Salamanders belong to Urodela while frogs and toads are in the group of Anura. Caecilians belong to group Apoda. Thus, this summarizes the difference between Urodela Anura and Apoda.

Reference:

1.“Amphibians – General Features.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., Available here.
2. “Amphibians.” Biology – Press Books, 22 Aug. 2012, Available here.

Image Courtesy:

1. “Fire salamander Slovenia” By Tiia Monto (CC BY-SA 3.0) via Commons Wikimedia
2. “1600569” (CC0) via Pxhere
3. “Uraeotyphlus narayani habitus” By Venu Govindappa – Venu Govindappa (CC BY 3.0) via Commons Wikimedia