How Do Amphibians Move? – (Locomotion & Movement in Amphibians)
Introduction
Amphibians with four limbs like frogs, salamanders, newts, etc. can walk, or run, and even swim. Amphibians like Sirens with only a pair of forelimbs and a long tail and caudal fin are better adapted to swimming. Axolotls and Mud puppy are with four limbs but are better adapted to swimming than walking.
Only a few amphibian species like frogs, toads, salamanders, etc. are better adapted to both walking and swimming. Frogs can even jump with ease using their hind limbs. Great majority of amphibians can swim in water.
Amphibians include those animals that are adapted to live both in water and on land. These are both air and water breathing.
Different authors have classified Amphibians with their own conception.
Amphibians are ectothermic, tetrapod (having four limbs) vertebrates that inhabit a wide variety of habitats, with most species living within terrestrial (on land), fossorial (burrowing the soil), arboreal (living in trees), or freshwater or semi-aquatic ecosystems.
Every young amphibian typically starts out as larvae living in water, but some species have developed behavioural adaptations to bypass this and started to habitat both land and water or anyone of these.
It is also important to note that they are able to respire by lungs, skin, and buccal cavity lining. They also have gills to respire with ease.
Many aquatic salamanders and all tadpoles have gills in their larval stage, with some (such as the axolotl) retaining gills as aquatic adults.
So, with so many adaptations, they are free to go in and out of the water whenever the need arises.
With these things in mind, evolution has allowed them to develop varied locomotory ways and mechanisms to move in both land or water.
By far as the meaning, locomotion is the movement that results in the amphibians changing place in 3-D space.
Here, in this post, we will learn how the amphibians move and locomote from one place to another place.
So, let’s get started…
How Do Amphibians Move? Let’s Know About The Locomotion & Movement in Amphibians
1. Wriggling Movement
Wriggling movement is a type of limbed locomotion that is seen in tetrapod amphibians like salamander, etc.
Wriggling movement is like a zig-zag movement that is seen when the salamander is swimming or walking rapidly.
This movement is like to move the body or a bodily part to and fro with short writhing motions like a worm. Or, you can simply say to move or advance further by twisting and turning.
Amphibians are a lot more clever with their mechanics than we often realize. They do gain both stability and maneuverability by moving in a zigzag path.
It has been stated that the body of salamanders is made up of segmented muscles and tissue parts that allow it to move in such a way providing extra flexibility and stretchability.
While in water, vigorous wriggling movements of the body and tail propel the amphibians like salamanders through the water in a similar way like a fish, but with less speed and precision.
2. Hopping Movement
Hopping movement is a type of bipedal movement that shows the best use of the hind limbs that are often highly developed, longer, and very muscular in those species that use it.
It is a type of saltatorial locomotion that is characterized as a form of movement based on jumping or hopping. Hopping means jumping with one foot and landing on the same foot.
This type of movement is seen in frogs and toads where the hindlimbs of the species are larger than the forelimbs.
The hindlimbs are very athletic in nature and help the frog’s heavy body to be lifted high up high in the air.
When the frog is in its resting position, the body remains inclined upward in front being supported on the forelimbs with its thumb pointing nearly backward. While the posterior part remains in the ground with the hindlimbs being folded.
When the frog wants to jump, it uses its hindlimbs to leap itself up high in the air just like a spring for jumping movements, and the forelimbs provide the direction of the jump.
Hindlimb bones of frogs are highly able to withstand the potentially erratic loads associated with high elastic jumps. And so, after a high jump the frog first lands on its hindlimbs that are perfectly able to withstand the pressure of the jump.
3. Swimming Movement
Many amphibian species like American hellbender, mud puppy, crested newt, etc. have fins in the form of the caudal fin or tail fin that help them swim and propel forward through the water.
In frogs, the webbed toes of the hindlimbs help the frog to swim forward by propelling the water backward. Their forelimbs help it to swim downward by beating the water upward or swim upward by beating downward.
In salamanders and newts, the forelimbs and hind limbs help them to provide the movement and propagation through the water. Their long, strong tails are flat to help them swim like a fish, with the tail flapping from side to side.
Salamanders and newts are also seen to follow the zig-zag pattern of swimming as well.
Frog and salamander larvae use lateral undulation to propel themselves through the water.
Salamander larvae, Necturus maculosus, and adult Notophthalmus viridescens can quickly perform lateral undulating movement while swimming with walking-like motions.
Turtles show a paddling type of swimming movement that is possible due to the modification of the walking movement inside water. They use their webbed fore-limbs and hind-limbs to provide thrust using a lateral sequence limb movement.
4. Walking or Running Movement
The walking or running type of movement is seen in frogs, toads, and even salamanders and newts because they have forelimbs with digits that help them run and walk with ease.
The fact is that the smaller the animal the better and swiftly they can run.
In walking or running movement, the amphibian species move its limbs diagonally as it moves ahead. This means that the organism can move its right forelimb and the left hindlimb ahead at the same time.
In running movement, salamanders are able to run quadrupedally in diagonal fashion i.e. by moving the left forelimb with the right hindlimb, and the right forelimb with the left hindlimb respectively, while following the wriggling type of movement as all at the same type.
Frogs can’t run, but they can walk for a little while whenever needed. They do so in the same diagonal fashion i.e. by moving the left forelimb with the right hindlimb, and the right forelimb with the left hindlimb respectively.
In every single step, the right forelimb and left hindlimb remain stationary on the ground while the left forelimb and right hindlimbs move forward. In such a way, with each and every step, the body of the organism moves forward.
During a run, salamanders and newts can balance its body due to the presence of its long tail that balances the center of mass of the lizard. Frogs can run because they have no tail to balance their center of mass, so they are better adapted to walking.
Running is usually smooth and rapid. It is powered partly by the leg muscles and partly by the back muscles.
The leg muscles are the primary muscles in this type of movement. These are striated in nature and consume enough energy than any other muscles used in their movement.
5. Hydrostatic Movement
There are other types of amphibians that look like a snake (reptile) but they aren’t. In fact, these are a group of limbless, vermiform, or serpentine amphibians.
These are Caecilians that belong to the Amphibain’s family of Caeciliidae, Chikilidae, Dermophiidae, Herpelidae, Ichthyophiidae, Indotyphlidae, Rhinatrematidae, Scolecomorphidae, Siphonopidae, Typhlonectidae. They mostly live hidden in the ground and in-stream substrates.
Examples of Caecilians: Ichthyophis (blindworm), Chikila fulleri (Kuttal caecilian), Chthonerpeton arii (rubber eel), etc.
Hydrostatic movement is usually seen in these Caecilian amphibian species because they don’t have any type of limbs to walk or run.
Hydrostatic movement is possible by the skeleton and deep muscles that are acting as a piston inside the skin and outer muscles to make movements forward. And, with their rear ends anchored, they take advantage of forceful muscular compression to drive their heads forward like a hydraulic ram.
During this movement, the amphibian body undergoes extension, anchoring, and contraction during the course of it’s progression.