BS Zoology Practical's Semester Wise Pdf
PRACTICAL NO .1
- STUDY OF INSECT CUTICLE, FISH SCALES, AMPHIBIAN
- SKIN, REPTILIAN SCALES, FEATHERS, AND MAMMALIAN SKIN
1) INSECT CUTICLE
Reasons for identification
i) Epicuticle of the waxy layer is present.
ii) Procuticle of chitin is present
3) GANOID SCALES
Reasons for identification
i)They are diamond(or rhomboidal ) shaped scales.
2) PLACOID SCALE
Reason for identification
i) These scales have a basal plate.
ii) A trident spine arises from the basal plate.
4) CYCLOID SCALES
Reasons for identification
i) More or less circular with concentric rings present around a central point.
5) CTENOID SCALES
Reasons for identification
i)Presence of concentric lines crossed by a few radiating ridges.
ii) The free border of the scale has spines called ctenidia
6) AMPHIBIAN SKIN
Reasons for identification
i)Presence of mucous and serous glands.
ii)Presence of outer thin layer of the epidermis and thick dermis...
7)DOWN FEATHER
Reasons for identification
i)They have a short calamus that bears a crown of free barbs.
ii)Lack of hooklet, so they are very fluffy.
8)FILOPLUMES
Reasons for identification
i)They are small hair-like feathers. They have a thread like a shaft
ii)Presence of tiny terminal tuft of barbs
9)CONTOUR/QUILL FEATHERS
Reasons for identification
i)Presence of barbs.
ii)Presence of the main shaft.
10)CARAPACE OF TORTOISE
Reasons for identification
i)Presence of a median row of 8 neural plates.
ii)Presence of marginal plates on each side of the costal plates.
11)PLASTRON OF TORTOISE
Reasons for identification
i)It is the ventral plate of the bony box. It consists of nine bony pieces.
ii)Presence of epiplastron,entoplastron,hypoplastron,xiphiplastron.
12)SKIN OF MAMMALS
Reasons for identification
i)Presence of hairs with hair follicles.
ii)Presence of sweat glands.
- SKELETON OF FROG(Rana tigrina)
- 1)SKULL(Dorsal View)
- 2)SKULL(Ventral View)
- 3)SKULL(Lateral View)
- 4)PECTORAL GIRDLE
- 5)FORE LIMB
Difference between male and female frogs:
Male frog Female frog
1. These are smaller. 1. These are larger.
2. These are dark in color. 2. These are lighter in color.
3. These have vocal sacs. 3. These don’t have vocal sacs.
4. These have nuptial pads on the undersurface
of the first finger during the breeding season
4. These do not have nuptial pads.
General anatomy of a frog
Procedure:
➢ Put a white paper in the dissecting tray and lay down the chloroformed frog on its back. Stretch
the fore and hind limbs and pin them.
➢ Add water to the tray so that the frog is submerged.
➢ Lift the abdominal skin with forceps and cut it longitudinally at the mid-ventral line from the
posterior to the anterior end.
➢ Also, cut the skin of the fore and hind limbs and separate it from the underlying muscles scalpel.
➢ Now cut the body wall along the mid-ventral line up to the lower jaw and open the body.
Rabbit( Oryctolagus cuniculus)
Dissection:
1. Fix the chloroform rabbit on the board by nailing the well-stretched legs.
2. Wet the ventral line and give a skin-deep incision along the mid-ventral line of the trunk and lungs.
3. Remove the skin of the ventral side to expose musculature.
Precautions:
➢ The incision of the neck needs special care not to damage.
➢ The blood vessels particularly in the region immediately in front of the sternum lead to the neck.
➢ Give the muscles a deep incision in the posterior abdominal region and follow it to the sternum.
➢ Cut the sternum with larger scissors so that the chest and abdomen are exposed
Vertebral column:
The centralLABEO ROHITA ;
Labeorohita is a common freshwater bony fish inhabiting rivers canals
dams lakes and ponds of Pakistan. Its color is dark brown or bluish-black with
red marks on scales on the back and sides while part of the sides and belly is
salivary. It is therefore being cultured by aquaculturists all over the country.
DISSECTION PROCEDURE ;
• Take a small preserved and fresh fish.Wash it thoroughly with water
• Carefully give a midventral longitudinal cut from the anterior-most part of
the trunk up to the anus Give transverse cuts from pelvic fins up to the base
of pectoral fins.
• Pin the flaps on a wooden board with a ventral side of the fish facing
you.
• Observe the digestive, excretory, circulatory, systems. remove the skin
with a bone cutter, cut away the frontal-parietal orbital
bones, opercular bones. column of the rabbit consists of 47 vertebrae. The vertebrae are divided
into five types according to their position .they are as follow
1. Cervical
2. Thoracic
3. Lumber
4. Sacral
5. Caudal
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