Morphology of frog

· The eyes are covered with thick pigmented immovable upper eyelid and rudimentary and movable lower eyelid. · A third eyelid called the Nictitating membrane is also present. It is an extension of the lower eyelid which. It is semi-transparent, freely movable. They are used for binocular vision and compensate for the absence of the neck. · Sexual dimorphism is well-marked with the male having a smaller and sturdy body, vocal sacs, copulatory pads and greater development of musculature. SEXUAL DIMORPHISM IN FROG · Sexual dimorphism: There are some differences in external characters by which male and female frogs can be distinguished. These are as follows. S.N Male Frogs Female Frogs 1. Smaller in size. Larger in size. 2. Darker in colour. Lighter in colour. 3. Due to the presence of vocal sacs, they croak loudly. Vocal sacs are absent. 4. Males are slimmer. Females are stouter especially when they contain eggs. 5. Forelimbs are relatively thick and muscular. The inner digit of the forelimb has a glandular swelling- nuptial pad at the ventral side. Nuptial pads are lacking in females. · This phenomenon of colour change is called Metachrosis. · The chromatophores are present in the stratum spongiosum just beneath the stratum germinativum. They are of 3 types: i. Lipophores: They contain Red and yellow pigments. ii. Melanophores: They contain Black and brown pigments. iii. Guanophores: They contain White pigment. · It has collagen fibres. Note: · The skin of a frog doesn't pla...

• The body is bilaterally symmetrical and dorsoventrally flattened. • The skin of frog is moist and slippery due to the presence of mucus. • The body of a frog is divisible into head and trunk. • A pair of nostrils is present above the mouth. • Eyes are bulged and covered by a nictitating membrane. These membranes protect the eyes while the frog is under water. • Ears are represented by membranous tympanum on either side of the eyes. • The forelimbs and hind limbs help in swimming, walking, leaping and burrowing. The hind limbs have five digits. The hind limbs are large and more muscular than forelimbs. The forelimbs have four digits. Webbed digits help in swimming. • Sexual dimorphism is present in frogs. • Sound producing vocal sacs and a copulatory pad (on the first digit of the fore limb) are present in male frogs.

Table of Contents • • • • • • • • • • • • • • • • • • In this article, We will learn the external morphology of frog ( Hoplobatrachus tigerinus or Rana tigrina) which is commonly known as the Indian Bull Frog. Rana tigrina is the previous scientific name of the Indian Bull Frog but it is recently updated to the Hoplobatrachus tigerinus. Systematic Position of Indian Bull Frog Kingdom: Animalia Phylum: Chordata Class: Amphibia Order: Anura Family: Dicroglossidae Genus: Hoplobatrachus Species: Hoplobatrachus tigerinus Diagram of Hoplobatrachus tigerinus External Morphology of Frog 1. Shape • As the frog spends most of its time in the water, its body is streamlined or spindle-shaped in order to swim more efficiently. • Its body is pointed anteriorly and rounded posteriorly. • The body is slightly dorso-ventrally flattened. 2. Size • Hoplobatrachus tigerinus varies from 12-18 cm in length. • It also varies from 5-8 cm in width. 3. Color • The color of the skin is green dorsally and pale-yellow ventrally. • There are numerous black or brown spots on the dorsal side of the body. • The Indian Bull Frog is called Hoplobatrachus tigerinus due to its mottled coloration like that of the tiger. • A light yellow mid-dorsal line runs from the tip of the snout to the cloacal opening on the back. • There are three layers of pigment cells in the skin of the frog. These pigments are melanophores, guanophores, and lipophores. 4. Skin • The skin of frog is thin, moist, slimy, smooth, slippery...

Frogs - Morphology And Anatomy Frogs are carnivorous tailless amphibians which are widely found in India. A diverse variety of frogs can be found all over the world; among them, the Indian frogs are called Rana tigrina. They are Morphology of Frogs Though larvae have tails, adult frogs are tailless. An adult frog has a stout body which is differentiated into head and trunk. Other external features are a pair of nostrils, protruding eyes, a membranous tympanum (ear), slippery/warty moist skin and webbed limbs. Frogs generally have a slippery moist and highly permeable skin through which they absorb water and respire. Thus, the moist skin acts as a respiratory organ in frogs. Also, the skin is glandular in nature, which produces mucus and toxic substances to warn them of their predators. The colour of the skin can vary from brown and green to vivid colours as per secretions. The locomotion of frogs takes place with the help of their forelimbs and hind limbs. Frogs are unisexual i.e., they show sexual dimorphism. A male frog is distinguished from a female frog by the presence of vocal sacs and a copulatory pad on forelimbs. A female frog lacks these body features. Below is an easy and well labelled diagram of frog ( Rana tigrina) for your better understanding. Anatomy The body plan of frogs consists of well-developed structures which help them in their physiological activities. The body cavity accommodates all the organ systems such as digestive, respiratory, circulatory, e...

Copyright Stephen Dalton/Photo Researchers As in other higher vertebrates, the frog body may be divided into a head, a short neck, and a trunk (see The internal organs of humans are housed in one of three distinct hollow cavities—the chest, the abdomen, and the pelvis. The human chest is separated from the abdomen by a powerful muscular partition, the The Skeleton and Muscles The frog’s body is supported and protected by a bony framework called the The skull is flat, except for an expanded area that encases the small brain. Only nine vertebrae make up the frog’s backbone, or vertebral column. The human backbone has 24 vertebrae. The frog has no ribs. The frog does not have a tail. Only a spikelike bone, the urostyle, remains as evidence that primitive frogs probably had tails. The urostyle, or “tail pillar,” is a downward extension of the vertebral column. The shoulders and front legs of the frog are somewhat similar to humman shoulders and arms. The frog has one “forearm” bone, the radio-ulna. Humans have two forearm bones, the radius and the ulna. Both frog and human have one “upper arm” bone, the humerus. The hind legs of the frog are highly specialized for leaping. The single “shinbone” is the tibiofibula. Humans have two lower leg bones, the tibia and the fibula. In humans and in the frog, the femur is the single upper leg (thigh) bone. A third division of the frog’s leg consists of two elongated anklebones, or tarsals. These are the astragalus and the calcaneus. The ...

Frogs Frogs are tail-less amphibians (class Amphibia, order Anura). With some 4,800 living species, frogs are the most numerous and best known of amphibians. They are found on all continents except “frog ” and “toad ” are derived from early usage in Frogs and their ancestors are among the most ancient of terrestrial vertebrates. A frog-like fossil animal more than 240 million years old is known from early Triassic rocks of Triadobatrachus, differs from true frogs in having more vertebrae in its Frogs are amphibians, a term derived from two Greek words: amphi meaning double and bios meaning life. The double life of frogs involves living in water and also on land. Because of this amphibious habit, they must have adaptations for each environment. As in other animals that have a separate larval stage and a complex life cycle, frogs have two extremely different morphologies. If frogs were not so common and familiar, they would be regarded as among the strangest of vertebrate animals. The typical frog has a broad head with an enormous mouth and protruding eyes. The body is short and plump, and there is no tail. The forelegs are rather short but normal-looking, and are used mainly for propping up the front part of the body and for stuffing food into the mouth. The hind limbs are much larger and more muscular, and have an extra joint that makes them even longer and provides extra power for jumping, which is their major mode of locomotion. Among aquatic frogs, the hind limbs also p...

Frog: any member of a diverse group of short-bodied, tailless amphibians. Kingdom: | Animalia Phylum: | Chordata Class: | Amphibia Order: | Anura There are over 5,000 species of known frogs, and scientists continue to discover new species. Frog species come in a variety of sizes and colors. They can be found in a variety of habitats on every continent except Antarctica. Frogs are amphibians, which are cold-blooded vertebrates, meaning they have backbones, that don’t have scales. Amphibians live both on land and in water. Other amphibians include salamander, newt, and caecilian. What’s the difference between frogs and toads? There isn’t a difference, the word “frog” includes both frogs and toads. While toads are frogs, toads tend to reference a frog that has particularly dry and warty skin. Toads also tend to have shorter legs and are more heavy-set. Frogs are more likely to live in or near water than toads. Size and Weight: Frogs vary widely in size and weight depending on species. For example, the West African goliath frog can grow to 15 inches and weigh as much as 7 pounds. Meanwhile, the Cuban tree frog grows to only half an inch and weighs approximately 2 ounces. Appearance: Frogs and toads have almost non-existent necks. However, most species have large, protruding eyes so they can see in most directions without needing to turn their head. Most species are also great at hopping in any direction. They have powerful muscles in their back legs, allowing them to hop great...

Frogs are small animals that can jump very well. Frogs are similar to Frogs are found throughout the world except in very cold places. They are most common in rain forests. Frogs are A frog has smooth, moist skin and big, bulging eyes. Its hind legs are more than twice as long as its front ones. Most frogs have webbed back feet to help them leap and swim. Tree frogs have sticky disks on the tips of their fingers and toes. These disks help them climb slippery surfaces. Many frogs are tiny. They can be less than an inch (2.5 centimeters) long. The largest frogs are about a foot (30 centimeters) long. Most frogs are green, brown, gray, or yellow. Some are brightly colored. A frog catches prey by flicking out its long, sticky tongue. Most frogs eat insects and worms. Some also eat other frogs, rodents, and reptiles. Frogs have glands in their skin that make poison. But this poison does not protect them from snakes, birds, and other enemies. Instead, frogs most often protect themselves by blending in with their surroundings. Frogs usually lay their eggs in water. There can be hundreds or thousands of eggs. Within a few weeks the eggs hatch into tadpoles. Tadpoles are fishlike creatures that breathe through gills instead of lungs. To become an adult frog, a tadpole loses its tail and develops lungs and limbs.