Difference Between Amphibians and Reptiles

introduction image

Amphibians and reptiles are the animals which belong to the phylum “Chordata” and are “Cold-blooded animals”. The significant differences between amphibians and reptiles are due to the differences in the properties like life cycle, fertilization and skin type.

Amphibians have dual existence in their life cycle, whereby getting birth they adapt themselves to the aquatic habitat and by attaining maturity they live in the terrestrial habitat. In contrast to this, reptiles do not exist such dual life cycle.

The type of fertilization is external in amphibians whereas internal in reptiles.

The skin type of amphibians is smooth and moist whereas hard and dry in reptiles.

Content: Amphibians Vs Reptiles

  1. Comparison Chart
  2. Definition of Amphibians
  3. Definition of Reptiles
  4. Similarities between Amphibians and Reptiles
  5. Key Differences Between Amphibians and Reptiles
  6. Conclusion

Comparison Chart

PropertiesAmphibiansReptiles
Identifying featureThese are having soft, smooth and moist skinThese are having hard and dry with scutes and bony plates surrounding it
Dual existenceThese exhibit “Dual existence” by living first in water during the larval stage and second by living in terrestrial habitat on maturityThese do not exhibit such property
ReproductionOviparous typeBoth oviparous and viviparous type
Fertilization typeExternalInternal
Scale presenceAbsentPresent
RespirationIt’s respiration can be through gills, lungs and skinIt’s respiration is mainly through lungs
Larval stage/MetamorphosisPresentAbsent
Longevity/Life spanComparatively lessMore
Defense mechanismBy nocturnal activity and aposematic colourationThrough Camouflage or by playing dead or retreats into the protective shell
WarningSecretes toxic substance like “Tetradotoxin” and vile tasting through the skin Warn predators by releasing foul smell and toxins
Additional sensory organThese can sense water pressure changes through their lateral lineThese are having “Vomeronasal organ” which releases chemical substance and also have thermoreceptors on their face to detect their prey in the dark
CirculationThrough three chambered heart which consists of two atria and one ventricleThrough three chambered heart which consists of two atria and one ventricle subdivides into two aortas
Neck vertebraSingle vertebra present on the neckMultiple vertebra present on the neck
Estimated number in earthMore than 8,000 amphibiansMore than 10,000 reptiles
ExamplesFrogs, toads, salamanders etc.Snakes, turtles, crocodiles, lizard etc.

Definition of Amphibians

These are the animals which belong to the phylum “Chordata” and class “Amphibia” which are ectothermic with soft and moist skin. Amphibians exist dual modes in their life cycle, wherein the first phase, i.e. larval stage they dwells in the aquatic habitat and the second phase, i.e. Maturity stage, they dwell in the terrestrial habitat.

Metamorphosis: The larval stage of amphibian have developed gills to respire in the water and on maturity, they have developed lungs to respire. Some of them use skin surface for the exchange of gases like frogs, terrestrial salamanders etc.

Nutrition and digestion: Amphibians have protruded and muscular tongue through which they can catch their prey. The prey then goes through the short oesophagus lined by cilia to the stomach by the help of mucus. The digestive enzyme “Chitinase” present in the stomach, helps in the digestion of chitinous cuticle of the prey.

Circulation: These contain three-chambered heart, i.e. two atria and one ventricle in their circulatory system.

Nervous system: The nervous system consists of a central brain, spinal cord and nerves with a less developed brain.

Excretion: For the excretion, these have two kidneys which excrete uric acid majorly from the cloacal vent.

Definition of Reptiles

These are the animals which belong to the phylum “Chordata” and class “Reptilia” which are ectothermic with hard and dry skin. Reptiles do not exhibit dual modes in their life cycle, and they can live in a variety of habitats.

Metamorphosis: Reptiles do not undergo a metamorphosis during their life cycle, i.e. they lack larval stage, unlike amphibians.

Respiration: For the process of breathing, these majorly respire through lungs and for the gaseous exchange, these have permeable skin and modified cloaca.

Skin: Reptiles can live in dry land as their skin is surrounded by “horny epidermis”. Scales or scutes are also present on the exposed parts of the reptiles which protects them from the direct heat. It lacks a thick dermal layer, unlike mammal.

Shedding: It is another property which distinguishes them from the amphibian, also refers as “Ecdysis” which occurs through their lifetime.

Circulation: Amphibians have three-chambered heart consists of two atria and one ventricle which subdivides into two aortas.

Nervous System: These also contain a central system, spinal cord and nerves. Reptiles are having twelve pairs of cranial nerves.

Excretion: The excretion system includes two small kidneys which mainly excretes “Uric acid” as nitrogenous waste.

Similarities between Amphibians and Reptiles

  • Amphibians and reptiles are cold-blooded animals.
  • Both of them belongs to the phylum “Chordata” which is the characteristic feature of possessing Central vertebral column.
  • Skin colour alternation is the property which is common in both the types, i.e. amphibian and reptile.
  • Both regulate the body temperature through skin colour alternation by dissipating melanin, and the process refers to as “Camouflage”.
  • Amphibians and reptiles are having keen eye-sight which helps them to feed on their prey by flicking their tongues.
  • Both can “Autotomize” refers as a process of removal of a tail as a defensive response.

Key Differences Between Amphibians and Reptiles

  1. Amphibians have soft, smooth and moist skin whereas reptiles have hard and dry skin with scutes and bony plates surrounding it.
  2. Dual existence” is a property which exhibits by amphibian as they first live in water during the larval stage and second by living in terrestrial habitat on maturity whereas reptiles do not exhibit such property.
  3. The reproduction is oviparous type in amphibians whereas in reptiles it can be both oviparous and viviparous type. Oviparous animals produce eggs external to the environment, and in contrast to this, viviparous animals give birth inside the female womb and undergo embryonic development.
  4. Scales are found on the body of the reptiles for the protection whereas absent in amphibians.
  5. The respiration of amphibian can be through gills, lungs and skin whereas in reptiles the breathing is entirely through the lungs.
  6. Reptiles undergo a metamorphosis during their life cycle whereas amphibian does not.
  7. The lifespan of amphibians is less compared to the life span of reptiles. For example, a turtle has 180 years of longevity whereas American bullfrog has 8 years of longevity.
  8. In amphibians, the defence mechanism is through nocturnal activity and aposematic colouration. Reptiles defend themselves through Camouflage or by playing dead or retreats into the protective shell.
  9. Amphibians secrete toxic substance like “Tetradotoxin” and vile tasting through their skin whereas reptiles warn predators by releasing foul smell and toxins.
  10. There are some additional sensory organs found in amphibians through which they can sense water pressure changes through their lateral line. In reptiles “Vomeronasal organ” is located on the top of mouth which releases chemical substance, and in addition to this, they also have thermoreceptors on their face to detect their prey even in the dark.
  11. The circulation of blood in amphibian is through the three-chambered heart (consists of two atria and one ventricle) whereas in reptiles a heart consists of two atria and one ventricle which subdivides into two aortas.

Conclusion

Therefore amphibian and reptile are the vertebrate animals which are ectothermic or cold-blooded. Both of them share many differences and some similarities, which we have discussed in this content.

We can distinguish both of them based on scale presence and skin type. The examples of amphibians are frogs, salamanders, toads etc. which lacks scales on their body and having moist and soft skin. The examples of reptiles are turtles, snakes, crocodiles, lizards etc. whose body is protected by the presence of scales with hard and dry skin.

1 thought on “Difference Between Amphibians and Reptiles”

Leave a Comment

Your email address will not be published. Required fields are marked *