Department of Zoology at ANDC/Zoology Museum/Museum specimens/Amphibia

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Class Amphibia

Date & Time : 24, November 2017 22:13



General Characteristics of Amphibia

  • cold blooded animal.
  • skin is smooth or rough.
  • skin is rich in glands to keep it moist.
  • scales whenever present are hidden in the skin.
  • skull consist of two occipital condyles.
  • limbs are tetrapodous pentaductyle type.
  • R.B.C. are biconvex, nucleated and oval in shape.
  • gills are present.
  • symmetric aortic arches.
  • eggs are usually laid in water.

Classification of Amphibia

A Few Examples

Uraeotyphlus

Geographical distribution: India, South Africa, Malay, Malabar hills and South America

Food: worms

Uraeotyphlus interruptus habitus

Characters:-

1. Burrowing, elongated vermiform and cylindrical form

2. Body:

a. dorsally – dark green or brown or black

b. ventrally – white

3. Skin is grooved transversely and contain cycloid scales

4. Small and conical head

5. Lidless eyes covered by skin

6. limbs and limb girdles absent

7. tail – short or vestigial

8. terminal cloaca

Salamandra

Salamandera.jpg

Common name: European fire-salamander

Geographical distribution: Europe and Asia

Habitat : terrestrial

Characters:-

1. Lizard like body

2. Body colour: yellow with black spots

3. Well- developed and strong limbs

4. Cylindrical tail

5. In adults gills absent

6. Movable eyelids

7. Absence of tympanic membrane or middle ear

8. Parotid glands present behind the head

9. Presence of teeth on both jaws

10. Vomerine teeth present

11. Opisthocoelous vertebrae

12. Reproduction :-viviparous

a. Development of 15 embryos occur in oviducts

b. Young – ones have external gill slits and metamorphosis occur later

Necturus

Necturus.jpg

Common name: mud puppy

Geographical distribution: North America and Yugoslavia

Habitat: permanently aquatic

Characters:-

1. Body elongated – 30-42cm in length

2. Body colour rusty brown with blackish spot

3. Long tail with caudal fin

4. Necturus is typical neotenic larva

5. Lungs present

6. Jacobson organ absent

7. Larval Characters:-

a. External gills:- 3 pairs in adult

b. Gill clefts: open and 2 in pairs

c. Lidless eyes

d. Large cartilaginous skull

e. Musculature larva

f. Larval circulatory system

g. Presence of lateral line organ

Bufo

True Toad.jpg

Common name: true - toad

Geographical distribution: all over world except Australia and Madagascar

Habitat: terrestrial and nocturnal

Food: carnivorous, feed on insects ,worms and snails

Characters:- 1. Skin – rough ,dry and watery dorsally

2. Large eyes

3. Small nostrils

4. Well – developed tympanum

5. Presence of parotid gland behind tympanum .It secrete irritating poison fluid

6. Fore-limbs: 3 webless fingers and thumb pad

7. Hind limb: 3 toes with reduced web

8. Teeth absent

9. Procoelous vertebrae

10. Ribs and sternum absent

11. Reproduction: eggs laid in water in strings

Hyla

Common name: Tree frog

Geographical distribution: cosmopolitan in damp forests except India and Africa

Habitat: arboreal

Hyla squirella


Characters:-

1. Skin:-smooth on dorsal surface and has papillae on ventral surface

2. Length: 2.5 – 7.5cm

3. Well – developed eyes , tympanum and nostrils

4. Fingers and toes have adhesive – pads or discs used for sticking on smooth surfaces

5. Poorly developed web

6. Upper jaw has teeth

7. Greatly expanded vocal sacs produce loud voice

8. Procoelous vertebrae

9. Exhibit mimicry

10. Female Hyla goeldii carried eggs on its back

Rhacophorus

Common name: flying - frog

Geographical distribution: R. maculatus and R. malabaricus in India , R.pardalis in Malaya Archipelago

Habitat: live on trees

Rhacophorus malabaricus flat

Characters:-

1. Slender body

2. Broad and conical head with eyes , nostrils and tympanum

3. Long and thin limbs with large feet

4. Development of web occur between digits in all 4 feet

5. Large web feet used in gliding from branch to branch or tree to tree

6. In air they can leap 6-10 m

7. Show parental care by depositing eggs in the nests near water

8. Can change colour rapidly

Rana

RanaTigrina.jpg

Common name: Indian bull - frog

Geographical distribution: world - wide

Habitat: moist places , fresh water ponds and streams

Food: carnivorous , feed on small worms , slugs ,snails and aquatic insects

Characters:-

1. Body colour :

a. Dorsal: green with black patches along with mid rib

b. Ventral: pale yellow

2. Flat head with more or less triangular

3. Dorsal surface of snout has external nostrils , 1 on each side of the median line

4. Large eyes with eyelids placed behind nostrils

5. Behind eyes pair or tympanum is present

6. Pentadactyle limbs

a. Forelimb: 4 fingers

b. Hindlimbs: 5 webbed toes

7. Teeth absent in lower jaw

8. Tongue: large, muscular and forked , attach in front and free behind

9. Vomerine teeth present , 1 on each side of internal nostrils

10. Procoelous vertebrae