CLICK THE IMAGE TO ENLARGE
Amphibians are a class of vertebrates between fishes and reptiles, resembling in some aspects the fishes and in some others the higher groups; i.e., amphibian embryos resemble those of fishes and their usual four limbs are similar to those of terrestrial vertebrates. Amphibia (Greek Amphibios) means “living a double life”. They live in water during an early stage of development and on land during the adult stage, but always dependent on water. They are thought to be originated from fish-like ancestors but then adapted to a living on land; for example, the adults have legs instead of paired fins, the gills of larvae disappear and the adults develop lungs.
The skin of an amphibian is naked; i.e., it does not contain scales, feathers or hairs; it is always kept moist by secretions of a lot of skin glands, some of which are poison glands.
Adult amphibians are carnivorous; insects, earthworms and some land snails being their main diet. While in their larval stages urodeles are carnivorous but anurans are herbivorous.
They usually metamorphose during their development; i.e., after the embryo they experience a larval stage, the duration of which is dependent on species, also on temperature and some other extrinsic conditions.
The urodeles exhibit various lively colours, while in anurans the colouration is in accordance with the environment. For example, Bufo viridis (Green Toad) is so well camouflaged in its environment, one notices it only when it jumps away.
Amphibians can not tolerate aridness and salinity in their environments. That is why they do not live in the seas and would not survive if their skins become dry.
CLICK THE IMAGE TO ENLARGE
Skeleton of a frog: web-footed amphibian which lives near lakes and ponds. Moves by swimming and jumping.
Maxillary: bony part of the jaw.
Orbital cavity: skull cavity that contains the eye.
Quadratojugal: cheek bone.
Prootic: bones forming the auditory region.
Phalange: each of the small bones forming the fingers.
Occipital lateral: occipital lateral bone.
Carpus: each of the bones forming the wrist.
Metacarpus: each of the bones forming the part of the hand between the fingers and the wrist.
Urostyle: adaptation of one or several vertebrae, stretching the hindquarters.
Ilium: projecting hip bone.
Ischium: one of three bones forming the ilium.
Calcaneum: projecting heel bone.
Talus: bone jointed with the leg bones.
Phalanges: each of the bones forming the toes.
Metatarsus: each of the bones forming the part of the foot between the toes and the heel.
Tarsus: each of the bones forming the heel.
Femur: thigh bone.
Tibiofibula: leg bone.
Sacral vertebra: vertebra of the sacrum.
Vertebra: each of the bones forming the spinal column.
Humerus: arm bone.
Radio-ulna: forearm bone.
Scapular: shoulder bone.
Pterygoid: one of the bones of the palate, forming the root of the mouth.
Skull: bony case of the brain
Maxillary: bony part of the jaw.
Orbital cavity: skull cavity that contains the eye.
Quadratojugal: cheek bone.
Prootic: bones forming the auditory region.
Phalange: each of the small bones forming the fingers.
Occipital lateral: occipital lateral bone.
Carpus: each of the bones forming the wrist.
Metacarpus: each of the bones forming the part of the hand between the fingers and the wrist.
Urostyle: adaptation of one or several vertebrae, stretching the hindquarters.
Ilium: projecting hip bone.
Ischium: one of three bones forming the ilium.
Calcaneum: projecting heel bone.
Talus: bone jointed with the leg bones.
Phalanges: each of the bones forming the toes.
Metatarsus: each of the bones forming the part of the foot between the toes and the heel.
Tarsus: each of the bones forming the heel.
Femur: thigh bone.
Tibiofibula: leg bone.
Sacral vertebra: vertebra of the sacrum.
Vertebra: each of the bones forming the spinal column.
Humerus: arm bone.
Radio-ulna: forearm bone.
Scapular: shoulder bone.
Pterygoid: one of the bones of the palate, forming the root of the mouth.
Skull: bony case of the brain
other sources:
2005-2009 - Bernard Dery
Image purchased by Mr. Lazaroff, by subscription, from http://www.clipart.com
No comments:
Post a Comment