class AMPHIBIA
Amphibians are the most important class in the vertebrate group, because they are the first four-legged vertebrates. Amphibians include frogs, toads, salamanders, caecilians and newts.
ECOLOGICAL ROLE
Amphibians play a vital role in ecosystems as secondary consumers in many food chains. Adult amphibians are great pest controllers. Other smaller amphibians also have a significant impact in the nutrient cycle.
Amphibians play a vital role in ecosystems as secondary consumers in many food chains. Adult amphibians are great pest controllers. Other smaller amphibians also have a significant impact in the nutrient cycle.
MOVEMENT STRUCTURES/ TYPE
Some amphibians don’t have legs, but most have four limbs with the fore limbs of some being smaller than the hind limbs.
Some amphibians don’t have legs, but most have four limbs with the fore limbs of some being smaller than the hind limbs.
BODY COVERING; CELL LAYERS; LEVEL OF ORGANIZATION; PROTECTION
Amphibian's skin is smooth, thin, and porous. They are hairless, featherless and scaless animals. Their skin contains both mucus glands and poison glands. Most amphibians have granular glands that secrete distasteful or poisonous substances.
Amphibian's skin is smooth, thin, and porous. They are hairless, featherless and scaless animals. Their skin contains both mucus glands and poison glands. Most amphibians have granular glands that secrete distasteful or poisonous substances.
SUPPORT
They have a bone skeleton with varying numbers of vertebrae; some have ribs some don't. Their bones are hollow and lightweight. The system is strong enough to enable it to support the head and body.
They have a bone skeleton with varying numbers of vertebrae; some have ribs some don't. Their bones are hollow and lightweight. The system is strong enough to enable it to support the head and body.
OBTAINING NUTRIENTS
The mouth is usually large with small teeth in upper and lower jaws. Many amphibians catch their prey by flicking out an elongated tongue with a sticky tip, before seizing the items with their jaws. Most amphibians swallow their prey whole without much chewing required.
The mouth is usually large with small teeth in upper and lower jaws. Many amphibians catch their prey by flicking out an elongated tongue with a sticky tip, before seizing the items with their jaws. Most amphibians swallow their prey whole without much chewing required.
RESPIRATION
Amphibians respire either separately, or in combination, by lungs, skin, and gills. Gills are usually absent in amphibians, so respiration typically occurs through the use of lungs or their skin. They have a permeable membrane through which gas exchange can occur.
Amphibians respire either separately, or in combination, by lungs, skin, and gills. Gills are usually absent in amphibians, so respiration typically occurs through the use of lungs or their skin. They have a permeable membrane through which gas exchange can occur.
CIRCULATION
Amphibians are cold-blooded exothermic animals that derive heat from outside their body. They have a three-chambered heart consisting of two atria and one ventricle. Amphibians have a pulmonary circuit, where blood is pumped from the heart to the lung and back, with a second circuit where blood is pumped to the body and back. They also have a third circuit that brings deoxygenated blood to the skin in order for gas exchange to occur. The blood flow is directed in two circuits; one through the lungs and back to the heart (pulmonary circulation) and the other throughout the rest of the body and its organs including the brain (systemic circulation). Blood entering the heart goes to the atrium then the ventricle, the ventricle then pumps blood to the gills. As the blood leaves the gills, the capillaries carry oxygen-rich blood to the capillary beds throughout the body then it returns to the heart.
Amphibians are cold-blooded exothermic animals that derive heat from outside their body. They have a three-chambered heart consisting of two atria and one ventricle. Amphibians have a pulmonary circuit, where blood is pumped from the heart to the lung and back, with a second circuit where blood is pumped to the body and back. They also have a third circuit that brings deoxygenated blood to the skin in order for gas exchange to occur. The blood flow is directed in two circuits; one through the lungs and back to the heart (pulmonary circulation) and the other throughout the rest of the body and its organs including the brain (systemic circulation). Blood entering the heart goes to the atrium then the ventricle, the ventricle then pumps blood to the gills. As the blood leaves the gills, the capillaries carry oxygen-rich blood to the capillary beds throughout the body then it returns to the heart.
EXCRETION
All amphibians have an excretory system. The kidney’s of an amphibian filter waste out of the blood. The urine travels in tubes called ureter which travels into the cloaca and is expelled. The urine can be passed outside the body or may be stored temporarily in a bladder just above the cloaca.
All amphibians have an excretory system. The kidney’s of an amphibian filter waste out of the blood. The urine travels in tubes called ureter which travels into the cloaca and is expelled. The urine can be passed outside the body or may be stored temporarily in a bladder just above the cloaca.
RESPONSE
Ten pairs of cranial nerve are present in amphibians. Their nervous system consists of a central brain, spinal cord and nerves that run throughout the body. They have two eyes and are capable of seeing and smelling.
Ten pairs of cranial nerve are present in amphibians. Their nervous system consists of a central brain, spinal cord and nerves that run throughout the body. They have two eyes and are capable of seeing and smelling.
REPRODUCTION
Some amphibian groups reproduce sexually via internal fertilization, whereas others use external fertilization. Eggs are usually laid in water or in a moist environment during external fertilization. Amphibian eggs don’t have a shell; instead they are surrounded by several gelatinous layers. When a frog reproduces, the male climbs onto the back of the female and squeezes. When this occurs, the female frog releases as many as 200 eggs.
Some amphibian groups reproduce sexually via internal fertilization, whereas others use external fertilization. Eggs are usually laid in water or in a moist environment during external fertilization. Amphibian eggs don’t have a shell; instead they are surrounded by several gelatinous layers. When a frog reproduces, the male climbs onto the back of the female and squeezes. When this occurs, the female frog releases as many as 200 eggs.