Study Of Virtual Specimens And Identification With Reasons

Aim Of The Experiment

To study the different slides and identifying them with various characteristics. The various specimens are:

• Amoeba
• Hydra
• Liver fluke
• Ascaris lumbricoidis
• Leech
• Earthworm
• Prawn
• Silkworm
• Snail
• Starfish
• Shark
• Rohu
• Frog
• Lizard
• Pigeon
• Rabbit

Materials Required

• Freshly prepared animal specimens
• Pencil
• Record file
• Eraser
• Sharpener
• Rules
• Practical guide/A laboratory guide

Amoeba Proteus

Classification

Discussion

• It is a microscopic, unicellular entity with a diameter of 0.2-0.5mm, appearing greyish in colour.
• The amoeba is usually found in ditches, ponds, lakes or rivers that contain adequate decomposed organic matter.
• When observed under a microscope, amoeba seems to be like a jelly that has an irregular shape containing a little mass of hyaline protoplasm. This protoplasm can be classified into a notable inner endoplasm and outer octoplasm.

Characteristic Features

• Irregular shape
• Unicellular
• Exhibit pseudopodia – They are blunt and finger-like projections that are used in locomotion and phagocytosis
• They exhibit contractile vacuole

Hydra

Classification

Features

• It is widely distributed in marine waters. It is precious and attacks the preys with powerful jaws.
• The body is long, laterally compressed and spindle-shaped that tapers at both ends.
• It can be distinguished into the head, trunk, and tail.
• The ventral surface is pale in colour while the lateral and dorsal body surface is dark grey.
• The skin is covered by an exoskeleton of dermal scales, placoid scales. The head is dorsoventrally flattened, which is produced to form a snout.
• The head has a large pair of circular eyes at the sides, the mouth is wise crescentic present ventrally. A pair of nostrils is present in the front.
• 5 pairs of naked gill slits are present behind the eyes.
• The trunk has two types of fins – lateral fins and median fins.
• Between the bases of the pelvic fins, a cloacal aperture is present
• Male sharks have a pair of claspers.

Carp (Labeo Rohita or Rohu)

Classification

Features

• It is a freshwater bony fish that is found in rivers and ponds. It is a source of food
• The body is compressed, fusiform and matures up to 1m in length. The body is distinguished into the head, trunk, and tail and is covered by a large overlapping cycloid scales
• Head is depressed to form a blunt snout and has a subterminal fringe lipped mouth with no teeth, a pair of eyes and nostrils
• Four pairs of gill slits on the lateral side of the body behind the eyes. The gill slits are covered by an operculum. The lateral line is clear and distinct.
• The trunk comprises of a pair of pectoral fins, a pair of pelvic fins, a dorsal fin a ventral or anal fin and a homocercal caudal fin.

Frog(Rana Tigrina)

Classification

Features

• It is terrestrial and nocturnal.
• The body is distinguished into the head and the trunk.
• The skin is warty and dry.
• The head has a pair of eyes, nostrils, tympanum, parotid glands and a mouth.
• The mouth is large with no teeth.
• The tympanum is well developed and the eyes are large.
• Behind the tympanum, the parotid glands are present, which secretes a poisonous fluid that has an irritating effect.
• The trunk has a pair of hind limbs, forelimbs, and at the posterior end there is a cloaca.
• Shorter forelimbs wherein each one has 3 webless fingers and a thumbpad.
• The hind-limbs are longer wherein each one has 3 toes with a highly reduced web.

See Also: Difference Between Frog And Toad

Lizard (Hemidactylus)

Classification

Features

• It is typically brown in colour and is 8-14cm in length.
• The body can be distinguished into the head that is thick and flattered, the neck is short, the trunk is large with a tapering tail.
• The head has a pair of eyes having movable eyelids, ear openings and nostrils.
• The skin is covered with tiny scales and is dry.
• The tail has annular pores of scales. These scales can be broken.
• They have four limbs, each having five clawed digits.

Pigeon (Columba Livia)

Classification

Features

• It is adapted for an aerial or volant mode of life and is a common domesticated bird.
• The body is boat-shaped and can be distinguished into the head, trunk and tail.
• The entire body surface except the feet is covered by feathers. The feet are covered by epidermal scutes
• The head has a pair of eyes, a pair of slit-like nostrils and a short beak.
• Eyes are large, rounded with movable eyelids and a nictitating membrane that is well developed.
• The forelimbs are modified into wings to take a flight.
• The hind limbs are pushed forward for bipedal locomotion. The digits end in claws.
• They have pneumatic bones. Teeth are absent and the skull is monocondylar.

Rabbit (Oryctolagus cuniculus)

Classification

Features

• The body can be distinguished into a head, trunk, neck and a small bushy tail.
• The entire body is covered with hair of black or brown colour
• The presence of two largely movable pinned behind the eyes. The colour of the eyes is pink.
• The mouth appears to have fleshy and soft lower and upper lips
• Sexual dimorphism is observed. Sexes are distinct and separate
• They possess the characteristic mammary glands, which end in nipples, located in the abdominal region.

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Further Reading