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PRACTICAL HAND BOOK BSc I ZOOLOGY
BSC I ZOOLOGY PRACTICAL
UNIT – I A
1) Classification and morphological
peculiarities of Nonchordates up to
classes
a) Protista – Amoeba, Paramoecium,
Euglena, Plasmodium.
b) Porifera – Sycon, Spongilla, Hyalonema
/ Euplectella.
c) Coelenterata – Hydra, obelia, Aurelia,
Sea anemone, Gorgonia
d) Platyhelminthes – Planaria, Liverfluke,
Tapeworm
e) Nemathelminthes – Ascarisf) Annelida –
Nereis, Earthworm, Leech.
UNIT – I B
1) Earthworm
a) Dissection of – i) Digestive system
ii) Nervous system
iii) Circulatory system
iv) Reproductive system
b) Mounting of i) Blood glands
ii) Septal nephridium
iii) Seteae
2) Mounting of Sponges (Demonstration)
i) Spicules
ii) Spongin fibres
UNIT – II
A) Study of following
a) Paramoecium - Binary fission and
conjugation
b) Sycon - T.S. / L. S.
c) Hydra - W.M. with bud, T.S. of hydra
through ovary & testis
d) Ascaris - male, female
B) Cytological Preparations
a) Mitochondria – Stained preparation of
mitochondria from onion peeling /Hydrilla
leaf / Oral mucosa by using Janus Green B
b) Polytene Chromosome – Stained
preparation of polytene chromosome in
Chironomous larva/ Drosophila larva
C) Examples in Genetics – Examples based
on Monohybrid cross, Dihybrid cross and
Multiple Alleles (At least 10 examples
must be solved)
UNIT – III
A) Classification of Chordates up to order
a) Urochordata - Herdmania, Salpa,
Doliolum
b) Cephalochordata - Amphioxus
c) Cyclostomata – Petromyzon, Myxine
d) Pisces – Dog fish, Hammer headed fish,
Sting ray, Electric ray, Labeo, Flying fish,
Sea horse, Eel fish
e) Amphibia – Ichthyophis, Frog, Toad,
Salamander
B) Study of following
a) Amphioxus – T.S. through pharynx, T.S.
through intestine,T.S. through tail
b) i) Various types of fins in fishes
ii) Homocercal & Heterocercal tail in fishes
iii) Gills of cartilaginous and bony fishes
C) Mounting of Fish scales
i) Placoid
ii) Cycloid
D) Frog - Demonstration of Heart,
Digestive system, Lungs, Kidneys, Ovaries,
Testis,Blood and Brain Axial and
Appendicular skeleton
Unit IV
A) Ecology- Ecological pyramids (at least
four)
B) Ethology-1) Mimicry in stick insect,
Camouflage in chameleon
2) Honey bee - Observation of Queen,
Drone, Worker bees and Bee hive
C) Evolution- 1) Connecting link –
Peripatus
2) Living fossil – Limulus
D) Applied Zoology -1) Sericulture - Life
cycle of mulberry silk worm: Egg, larva,
Cocoon, adult (male & female)
Study Tour – Visit to sea shore or any
other suitable place to study Ecosystem,
Animal Diversity, Animal behaviour etc.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
1. CLASSIFICATION OF NONCHORDATES
Kingdom: Protista
General characters
1. These are microscopic, acellular or unicellular animals.
2. These are aquatic, fresh water or marine, some are found in damp soil and some are
parasitic.
3. Body is made up of a mass of protoplasm with one or many nuclei.
4. Locomotry organs are pseudopodia, cilia or flagella.
5. Nutrition is generally, holozoic or holophytic or saprozoic or sometimes parasitic.
6. Respiration and excretion occur through general body surface by diffusion.
7. In freshwaters osmoregulation by contractile vacuoles.
8. Reproduction sexual or asexual
9. Kingdom Protista is divided in to following four phyla
10. Phylum : Sarcodina, Ciliophora, Zoomastigina and Sporozoa
AMOEBA
KINGDOM: PROTISTA
PHYLUM: SARCODINA
CLASS: RHIZOPODA
COMMENTS
1) Amoeba is found in mud, fresh water ponds, streams and ditches in which bacteria
and decaying vegetation are rich.
2) Shape of body is irregular.
3) Body is covered by very thin and semi-permeable membrane called plasma lemma.
4) Protoplasm is divisible into an outer ectoplasm and an inner endoplasm.
5) The endoplasm is having single nucleus, a large single contractile vacuole and many
food vacuoles.
6) Pseudopodia are locomotory organs, which are short and blunt.
7) Nutrition is holozoic.
8) Reproduction is by binary fission.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
PARAMOECIUM
KINGDOM: PROTISTA
PHYLUM: CILIOPHORA
CLASS: CILIATA
COMMENTS
1) Paramecium is found in the mud, fresh water ponds, ditches in which organic matter
and decaying vegetation is rich.
2) It is commonly known as slipper animalcule.
3) Body is slipper-shaped covered by the pellicle and cilia.
4) The cilia are arranged uniformly throughout the body, while at the posterior end of
the body they are longer.
5) Protoplasm is divisible into an outer ectoplasm and an inner endoplasm.
6) The ectoplasm lies under the pellicle which contents trichocysts.
7) The endoplasm contains two nuclei, i.e. Macronucleus and micronucleus, two
contractile vacuoles, i.e. anterior and posterior contractile vacuoles and many food
vacuoles containing food material.
8) The oral groove runs backwards and ends into the mouth or cytostome.
9) Cytostome leads into a narrow cytopharynx, at the base of which food vacuoles are
developed.
10) Cilia are the locomotory organs.
11) Nutrition is holozoic.
12) Asexual reproduction is by binary fission and sexual reproduction is by conjugation,
endomixis, autogamy and hemixis.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
EUGLENA
KINGDOM: PROTISTA
PHYLUM: ZOOMASTIGINA
CLASS: MASTIGOPHORA
COMMENTS
1. Euglena is fresh water flagellate, found abundantly in ponds, ditches, pools and slow
running streams.
2. The body is spindle – shaped, green coloured, measuring about 50-100 microns
length.
3. The outer covering is called pellicle. The pellicle is marked by spiral striations.
4. The cytoplasm divisible into an outer ectoplasm and an inner endoplasm.
5. The endoplasm contains nucleus, chloroplast, paramylum and pyrenoids.
6. The anterior end contains flask shaped cytopharynx or gullet.
7. Just below the cytopharynx lies a large contractile vacuole which is surrounded by
accessory vacuoles.
8. Just above the contractile vacuole lie stigmata or eye spot which serves as
photosensitive organ. It is a mass of red hematochrome granules.
9. A long flagellum originating from blepharoplast projects through the cell gullet.
10. Locomotion is due to the lashing movements of the flagellum, i.e. euglenoid
movement.
11. Chloroplast is made up of a central pyrenoids enclosed in paramylum.
12. Nutrition is holophytic or saprophytic.
13. Reproduction usually by the binary fission.
PLASMODIUM
KINGDOM: PROTISTA
PHYLUM: SPOROZOA
CLASS: TELOSPOREA
COMMENTS
1. Plasmodium is a malaria parasite.
2. Life cycle of plasmodium is complicated and is completed in two hosts, man and
mosquito.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
3. Asexual cycle is passed in man in two phases. First phase in liver schizogony and
second phase is completed in red blood cells and is known as erythrocytic
schizogony.
4. Signet ring stage is a part of the erythrocytic schizogony.
5. After liver schizogony a stage called micro-metacryptomerozoite invades the red
blood cells and becomes rounded to form a young trophozoite.
6. As the trophozoite grows in size, a central vacuole is developed.
7. As a result of this the nucleus is pushed to one side into peripheral cytoplasm.
8. This stage is clinically referred to as signet – ring sage.
9. Signet- ring trophozoite secretes digestive enzymes which bring lyses of
haemoglobin into protein and haematin.
10. Protein is utilized by the trophozoite and he unused haematin toxic material pigment
called haemozoin.
PHYLUM: PORIFERA
GENERAL CHARACTERS
1. These are strictly aquatic, fresh water or marine.
2. Multicellular body but cells are present in loose aggregation and tissues are not
formed.
3. These are diploblastic. The outer layer is ectoderm and inner layer is endoderm. In
between these two there is a gelatinous layer called mesoglea.
4. Presence of Ostia, osculum, incurrent pores and excurrent pores. Presence of canal
system. Spongin fibres and spicules form skeleton.
5. Reproduction by sexual as well as asexual.
6. Phylum Porifera is divided into following three classes ie class – Calcaria,
Hexactinellida and Demospongia.
SYCON
KINGDOM: ANIMALIA
SUBKINGDOM: PARAZOAPHYLUM: PORIFERA
CLASS: CALCAREA
COMMENTS
1. Sycon is a solitary colonial sponge, found attached to the rocks and other substratum
in shallow sea water.
2. The body is slender vase-like or cylindrical.
3. The surface of the body is perforated by numerous pores called ostia.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
4. Each cylinder is attached to the substratum by base and opens to the exterior by an
opening called osculum.
5. Osculum is fringed by monaxon spicules.
6. The body wall is made up of the dermal epithelium.
7. Skeleton mainly consists of the calcareous spicules, which project out from the
epithelium.
8. Each cylinder has a central large cavity called the spongocoel.
9. The spongocoel opens outside through the osculum.
10. Nutrition, respiration and excretion are performed by canal system.
11. Reproduction by both asexual and sexual mode.
EUPLECTELLA
KINGDOM: ANIMALIA
SUBKINGDOM: PARAZOA
PHYLUM: PORIFERA
CLASS: HEXACTINELLIDA
COMMENTS
1) It is commonly called as Venus flower basket due to its beautiful elegant glassy
shape.
2) The animal measures 15-30 cm. in diameter.
3) The body is long, rigidly curved and cylindrical.
4) Body is composed of 4 and 6 rayed spicules forming 3 dimensional networks with
parietal gaps.
5) The spicules are joined together forming a network.
6) It has knitted basket shaped body, ostia and oscular sieve plate hence it is
euplectella.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
HYALONEMA
KINGDOM: ANIMALIA
SUBKINGDOM: PARAZOA
PHYLUM: PORIFERA
CLASS: HEXACTINELLIDA
COMMENTS
1. It is exclusively marine in habitat found at the depths of 100-150 meters.
2. Body shape is variable, usually rounded or oval.
3. The body looks like a structure of glass wool with projecting tufts of glass spicules.
4. Body is supported by spicules of six – rays and small amphidiscs.
5. Body is raised from the substratum by a stalk – like root tuft which is twisted like a
rope.
6. Root tuft is made up of a bundle of very long anchoring spicules.
7. Root tuft also traverses the body as an axis or columella and usually project above as
gastral cone.
SPONGILLA
SPONGILLKINGDOM: ANIMALIA
SUBKINGDOM: PARAZOA
PHYLUM: PORIFERA
CLASS: DEMOSPONGILLA
COMMENTS
1) Spongilla is fresh water, colonial
sponge which occurs in streams,
lakes and ponds.
2) It is found attached as branching
tubes to the submerged objects.
3) It is yellow or green in colour due
to the presence of green algae,
zoochlorellae.
4) The body wall is perforated by
dermal pores or ostia and several
osculae.
5) Te skeleton consists of both
spongine fibres and the siliceous
spicules.
6) Canal system is of rhagon type.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
PHYLUM : COELENTERATA
GENERAL CHARACTERS
1. These are aquatic animals; some
are fresh water while some are
marine water.
2. They may be solitary, colonial, and
sedentary or free swimming.
3. They possess a cavity called
coelenteron and are diploblastic
having non cellular mesoglea.
4. The animals are radially
symmetrical and appear in two
forms polyp and medusa.
5. Reproduction sexual as well as
asexual.
6. Digestion both extracellular and
intra cellular.
7. Special types of cells i.e. stinging
cells are present.
8. This phylum is divided in to
following three classes
9. Phylum – Hydrozoa, Scyphozoa,
and Anthozoa
and lakes, attached to some
objects.
2. The body is elongated, cylindrical
and tube like.
3. The proximal end of the body is
known as basal disc or foot while
the free distal end is known as oral
end.
4. Mouth is situated on a conical
elevation called hypostome.
5. The hypostome is encircled by 610 tentacles.
6. The
tentacles
are
having
nematocysts.
7. Lateral buds give rise to new
individuals
by
asexual
reproduction.
8. Gonads i.e. testes lies near the oral
end while the ovaries near the
base.
9. Asexual reproduction takes place
by means of budding and sexual
reproduction by the fusion of
gametes.
10. Hydra has great experimental
value because most of the
regeneration
and
grafting
experiments are being conducted
on it.
HYDRA
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETASOA
PHYLUM: CNIDARIA /COELENTERATA
CLASS: HYDROZOA
COMMENTS
1. Hydra is solitary or colonial
coelenterate animal, found in fresh
water bodies like ponds, streams
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PRACTICAL HAND BOOK BSc I ZOOLOGY
OBELIA
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: CNIDARIA /COELENTERATA
CLASS: HYDROZOA
COMMENTS
1. Obelia is a colonial, marine, sedentary coelenterate, attached to seaweeds, shell and
rocks.
2. The colony of Obelia is made up of the branches and zooids.
3. The colony is having as inner, tubular and living part the coenosarcs.
4. The coenosarcs is surrounded by tough and non living layer called the perisarc.
5. The coenosarc is continuous with the zooids.
6. The colony of the obelia is dimorphic i.e. it shows two types of zooids.
7. The zooids are the polyps or hydranths and blastostyles.
8. The polyps or hydranths are nutritive in function and called as gastro zooids.
9. The blastostyles are reproductive in function, so called as gonozooids.
10. The perisarc is a yellowish or brown, tough, transparent layer.
11. The perisarc is a protective layer made up of the cuticle.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
JELLY FISH /AURELIA
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETASOA
PHYLUM: CNIDARIA /COELENTERATA
CLASS: SCYPHOZOA
COMMENTS
1. It is exclusively marine and
commonly known as jelly fish.
2. Body is soft bell or umbrellashaped, perfectly transparent and
bluish in colour.
3. The reddish or pinkish horseshoeshaped, gonads are clearly visible
from the surface.
4. The circular body presents a
concave oral or subumbrellar
surface.
5. From the centre of sub – umbrellar
surface hangs down a short
manubrium.
6. At the free distal end of
manubrium a squarish mouth is
present.
7. From each corner of the mouth
hangs down a long, tapering much
– frilled delicate oral arm.
8. Each oral arm has ventral ciliated
groove leading into mouth.
9. The edges of arms are beset with
stinging cells called nematocysts.
10. The circular margin of umbrella is
broken into 8 lobes by notches. In
each notch is a sense
organ
called tentaculocyst.
11. The free edge of umbrella is base
with closely set delicate hollow
marginal tentacles.
SEA ANEMONE
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: CNIDARIA /COELENTERATA
CLASS: ANTHOZOA
COMMENTS
1. Strictly marine, solitary or colonial
and are fixed to substratum.
2. These are only polyps medusoid
stage is absent.
3. Coelenteron is divided and
mesoglea contains cells and fibres.
4. Body is short cylindrical and
radially symmetrical. It is divided in
to pedal disc, column and oral disc.
5. Pedal disc is attached to
substratum firmly and the column
forms major part of the body.
6. The column is divided in to an
upper short thin walled capitulum
and lower thick walled scapus.
7. The capitulum and the scapus are
separated by a prominent fold
called as collar.
8. Oral disc is expanded and crowned
with several marginal tentacles
around the mouth.
9. It is dioecious animal and asexual
reproduction by budding and
fragmentation.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
GORGONIUM
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: CNIDARIA /COELENTERATA
CLASS: ANTHOZOA
1. Commonly called as sea fan. It is colonial and occurs in all seas.
2. The colony looks like a tree and it is yellowish or reddish in colour.
3. It forms erect branches in one plane connected by cross connections in a feathery
manner and the shape of the body becomes fan like so called Sea Fan.
4. The branches are united by numerous cross branches forming a network which is
calcareous in nature.
5. The base of the colony is expanded to form a hold fast or attachment organ.
6. The polyp emerges from branches.
7. The skeleton consists of horn like material called gorgonin, embedded in mesoglea.
8. Sexes are separate.
9. The dried skeleton is often displayed as ornament.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
GENERAL CHARACTERS OF PLATYHELMINTHES
1. Soft bodied, dorsoventrally flattened, free living, triploblastic, coelomate and some
are endoparasitic.
2. For the first time in the animal kingdom, the head region, definite organ systems like
digestive, excretory, nervous and reproductive system is getting formed. Digestive
system is incomplete due to absence of anus.
3. Ingestion through mouth or through general body surface.
4. Excretory system consists of flame cells. These are mostly bisexual and fertilization is
internal.
5. This phylum is divided into following three classes
6. Class – Turbellaria, Trematoda and Cestoda
PLANERIA/DUGESIA
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: PLATYHELMINTHES
CLASS: TURBELLARIA
1. These are mostly free living flatworms. Fond in fresh water streams, ponds, pools
etc.
2. Body is cylindrical having head at the anterior end.
3. Body is covered by ciliated epithelium.
4. Mouth is ventral, pharynx is protrusible.
5. Alimentary canal consists of mouth, proboscis, oesophagus and intestine.
6. Gonopore is situated just behind the proboscis pore.
7. Mostly bisexual, reproduction by sexual and asexual method. Asexual by
regeneration.
8. Ex. : Dugesia (Planaria)
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PRACTICAL HAND BOOK BSc I ZOOLOGY
LIVERFLUKE
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: PLATYHELMINTHES
CLASS: TREMATODA
1. It is found in the bile ducts of liver and bilary passage of sheep, ox, horse, dog, man,
monkey etc.
2. Body is leaf like, dorso-ventrally flattened.
3. Mouth is situated at the anterior and ventral side, which is surrounded by the oral
sucker.
4. An adhesive acetabulum or ventral sucker is found little behind the mouth and oral
sucker. Between the oral and ventral sucker there is a gonopore.
5. Excretory pore is at the posterior end of the body.
6. Animal is hermaphrodite i.e. both male and female reproductive organs are in one
and in the same animal
7. Liver fluke causes disease in sheep is called liver rot.
TAPEWORM
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: PLATYHELMINTHES
CLASS: CESTODA
1. It is an endoparasite in the intestine of man.
2. The body is ribbon like, differentiated in to scolex, neck and about 700-900
segments.
3. Scolex contains 4 suckers and a rounded rostellum.
4. Rostellum is crowned at its base by a double row of 28-32 hooks.
5. Below the scolex there is a area of segmentation called the neck.
6. Neck is followed by a large number of immature, mature and gravid proglotids or
segments.
7. Mature segments contain fully developed hermaphroditic genital organs.
8. Male reproductive system consists of testes, vasa efferentia, vas deferens and cirrus.
9. Female system consists of a single bilobed ovary, oviduct, vitellaria and vagina.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
10. Ingestion of improperly cooked pork beef leads to the infection.
11. It causes various diseases in man like anaemia, eosinophilia, diarrhoea,
haemorrhage, abdominal pain, nausea etc.
ASCARIS
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: ASCHELMINTHES
CLASS: NEMATODA
1. Ascaris is a common endoparasite in the small intestine of man.
2. It is commonly known as round worm.
3. Body is elongated, cylindrical, pointed at both the ends.
4. Body is marked with mid –dorsal, mid-ventral and two lateral lines.
5. Mouth is situated at the anterior end.
6. Posterior end of the male is ventrally curved, having cloacal aperture.
7. Through the cloacal aperture two spicules project out, known as penial setae.
8. Posterior end of the female is bluntly pointed, having anus.
9. Excretory pore in male and female is situated at the anterior end just below the
mouth.
10. Female genital aperture or gonopore lies about 1/3 of the length of the body from
the anterior end.
11. Male is smaller than the female.
12. Anus, in case of male opens into the cloacal aperture.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
GENERAL CHARACTERS OF PHYLUM ANNELIDA
1. These are mostly aquatic, freshwater or marine. Some are terrestrial, burrowing, and
some are found in moist soil.
2. Body is elongated vermiform, bilaterally symmetrical.
3. The animals are metamerically segmented. External segmentation due to the
transverse groove while the internal segmentation is due to the presence of septa.
4. The body wall is composed of longitudinal as well as circular muscles and is covered
by cuticle.
5. These are triploblastic and coelomate animals, respiration by general body surface.
6. Circulatory system is well developed and is of closed type.
7. Blood is red in colour due to hemoglobin which is dissolved in plasma.
8. Excretion by nephridia, locomotion by setae, parapodia or suckers.
9. The sexes are separate or united.
10. Phylum annelida is divided into following four classes i.e. classes – Polycheta,
Oligochaeta, Hirudenia and Archiannelida
EARTHWORM
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: ANNELIDA
CLASS: OLIGOCHAETA
GENUS: PHERETIMA
SPECIES: POSTHUMA
1. It is found in moist soil.
2. Body is long cylindrical and brown in colour.
3. Anterior end is pointed, while the posterior end is more or less blunt.
4. Each segment of the body except the first and last segment provided with setae.
5. Mouth is situated antero- ventrally.
6. Clitellum is present in 14th, 15th and 16th segments.
7. Female genital pore is present midventrally in the 14th segment.
8. A pair of male genital pores lies ventrally in the 18th segment.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
9. Two pairs of genital papillae lie ventrolaterally on the 17th and 19th segment.
10. The anus is present in the last segment.
11. Sexual reproduction.
NEREIS
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: ANNELIDA
CLASS: POLYCHAETA
1. Nereis is commonly called as Rag worm or clam worm
2. Distinct head with sense organs like eyes, cirri, palps, tentacles.
3. Parapodia are the organs of locomotion and respiration.
4. Head and anal segments without parapodia.
5. Mouth lies on the anterior surface of the prostomium.
6. Many bristle or setae are extended from parapodia in bundles so called Polycheta.
7. Anal segment contains a pair of locomotory parapodia.
8. Sexes separate, fertilization external.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
LEECH
KINGDOM: ANIMALIA
SUBKINGDOM: EUMETAZOA
PHYLUM: ANNELIDA
CLASS: HIRUDENIA
1. It is commonly called as Indian cattle leech found in ponds, marshes and streams.
2. It is ectoparasite.
3. Number of body segments 33. Each segment show superficial divisions called
annuli.
4. Presence of suckers for locomotion and attachment.
5. Indistinct head with five pairs of eyes situated dorsally in the first five segments.
6. Animals are bisexual
7. The male genital pore is situated mid-ventrally in between the 10th segment.
8. The female genital pore lies mid-ventrally on the 11th segment.
9. The anus lies mid-dorsally on the 26th segment.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
EARTHWORM DISSECTION
CIRCULATORY SYSTEM OF EARTHWORM
1. The circulatory system of earthworm is well developed and is of closed type.
2. The blood vascular system is divisible into following parts
a) Longitudinal blood vessels and their branches
b) Hearts and loops joining the longitudinal vessels.
3. The major longitudinal blood vessels are dorsal blood vessel, ventral blood vessel,
latero oesophageal blood vessel, sub neural blood vessel and supraoesophageal
blood vessel.
4. There are four pairs of hearts located in the segments 7th, 9th (lateral hearts), 12th
and 13th (latero-oesophageal hearts).
5. Two pairs of anterior loops in the segment no 10th and 11th segment carries blood
from latero- oesophageal vessel to supra- oesophageal blood vessel.
NERVOUS SYSTEM OF EARTHWORM
Nervous system of earthworm consist s of following parts.
1) Supra pharyngeal ganglia – These are two in number, fused, present in the middle of the
third
segment, above the pharynx. These are fused to form brain.
2) Sub pharyngeal ganglia - These are two in number, present below the pharynx in the
fourth segment. These are fused.
3) Circum pharyngeal connectives- These are two in number, one on either side of the
pharynx. These connect brain with the sub pharyngeal ganglia.
4) Ventral nerve cord- it is present below alimentary canal. It extends from the subpharyngeal ganglia to the last segment. In each segment it possesses a segmental `
ganglion.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
TEMPORARY MOUNTINGS OF EARTHWORM
SEPTAL NEPHRIDIUM OF EARTHWORM
1. These are attached to the each intersegment septum behind the fifteenth segment
up to the last segment.
2. Each septal nephridium consists of nephrostome, neck, body of nephridium and the
terminal duct.
3. Nephrostome is rounded funnel like lined by ciliated cells.
4. Through the nephrostome nephridium opens into the coelom.
5. Body of the nephridium comprises a short straight lobe and a long spirally twisted
lobe.
6. Long spirally twisted lobe is differentiated in to proximal and distal limbs.
7. Terminal duct is a small duct and joined with the proximal limb of the twisted lobe.
8. These are excretory in function, collect nitrogenous wastes from the coelom and
discharge it through the intestine.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
BLOOD GLANDS OF EARTHWORM
1. Blood glands are present on the sides of the oesophagus in segments 5 and 6.
2. These are pinkish masses located inside the oblique septum of that segment.
3. Blood glands are rounded bodies containing small cells.
4. Function: Synthesis of new blood cells and also of haemoglobin
STUDY OF SPONG SPICULES
1. Take a piece of sponge body in a test tube and add 5 ml. of NaOH or KOH (10%).
2. Boil slowly the proteins get dissolved and spicules get settled at the bottom.
3. Take this slag on slide and observe under microscope.
4. Monaxon consists of a single axis, either straight or curved e.g. style or monaxon,
diactinal, ‘C’ shaped etc.
5. Tri axon consists of three axes, which may further divided to form six rays.
6. Tetra axon consists of four rays. One of them may get lost later. If one of the rays
elongate and bears disc at both end, then the spicules is called amphidiscs.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
STUDY OF BINNARY FISSION IN PARAMOECIUM
1. Binary fission is a method of asexual reproduction.
2. The, cytoplasm, micronucleus and macronucleus undergoes transverse division.
3. Micronucleus elongates and divides by mitosis.
4. Macronucleus elongates and divides by amitosis.
5. The cytoplasmic constriction is developed at the middle which divides the cell
into two halves.
6. Each half of the cell is having a daughter nucleus and a contractile vacuole.
7. Buccal grove is also divided into two.
8. In both individuals the missing parts of the buccal grove develop.
9. Finally the separation of two daughter cells takes place, thus two individuals are
formed, which is called as binary fission.
STUDY OF CONJUGATION IN PARAMOECIUM
1. Conjugation is a method of sexual reproduction in paramecium.
2. Two paramecia come in contact for mating and unite together by their own grooves.
3. The pellicle between two individuals gets disintegrated.
4. In each conjugant macronucleus disappears.
5. The micronucleus divides twice meiotic ally and forms four haploid daughter
micronuclei.
6. Out of four daughter micronuclei, three disintegrate in each conjugant.
7. Remaining one daughter micronucleus divides mitotically into two unequal
pronuclei.
8. The smaller one is called as male pronucleus while the larger one is called as female
pronucleus.
9. Male pronucleus of one conjugant moves through the protoplasmic bridge into other
conjugant and fuse with the female nucleus to form zygote and vice versa.
10. Zygote nucleus is diploid and is called as synkaryon or amphinucleus.
11. The conjugants undergo separation and each one is now called as exconjugant.
12. By repeated nuclear divisions, each exconjugant produces four daughter paramecia.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
STUDY OF L. S. OF SYCON
1. It is cylindrical in outline.
2. The body wall is made up of three loosely organised layers.
3. The body wall layers are outer ectoderm, inner endoderm and the layer in between
these two is mesenchyme.
4. The ectoderm which is also called as dermal epithelium is made up of large,
flattened polygonal ectodermal cells.
5. The ectodermal cells are closely cemented together and perforated by dermal pores
or ostia.
6. Middle mesenchyme is made up of gelatinous matrix.
7. The gelatinous matrix contains the spicules and the cells like scleroblasts,
collencytes, archeocytes, chromocytes, germ cells and gland cells.
8. The endoderm consists of collar cells or Choanocytes.
9. The body wall shows finger like projections of the flagellated chambers or radial
canals.
10. The radial canals are lined by Choanocytes.
11. In between two radial canals lies an incurrent canal which is having one or two
dermal ostia.
12. Each incurrent canal is open into the radial canal by many openings called the
prosopyle.
13. Each radial canal open into spongocoel by an opening called apopyle.
14. Spongocoel is a central large hollow chamber in which all radial canals open.
15. Spongocoel opens to outside by a large opening called the osculum.
16. The canal system is of syconoid type.
17. The course of circulation of water is as follows
Ostia
incurrent canal
Prosopyles
Radial-canals
Apopyles
Spongocoel
Osculum
Outside.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
HYDRA WHOLE MOUNT WITH BUD
1. Hydra is solitary or colonial coelenterate animal, found in fresh water bodies like
ponds, streams and lakes, attached to some objects.
2. The body is elongated, cylindrical and tube like.
3. The proximal end of the body is known as basal disc or foot while the free distal end
is known as oral end.
4. Mouth is situated on a conical elevation called hypostome.
5. The hypostome is encircled by 6-10 tentacles.
6. The tentacles are having nematocysts.
7. Lateral buds give rise to new individuals by asexual reproduction.
8. Gonads i.e. testes lies near the oral end while the ovaries near the base.
9. Asexual reproduction takes place by means of budding and sexual reproduction by
the fusion of gametes.
10. Hydra has great experimental value because most of the regeneration and grafting
experiments are being conducted on it.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
T. S. OF HYDRA PASSING THROUGH TESTIS
1. Testes appear as conical elevations of the body wall and are usually located near the
distal or oral end of the body.
2. A testis is formed by the local proliferation of the intestinal cells of the epidermis.
3. A testis is externally covered by a capsule of large epidermal cells.
4. Towards the basal region of the testis, the intestinal cells become differentiated into
spermatogonia.
5. These spermatogonia undergo typical spermatogenesis and after passing through
primary spermatocytes, secondary spermatocytes spermatids become sperms.
6. Each sperms have a head with nucleus and a long vibratile tail.
7. Mature sperms are discharged by the rupture of testis wall at its apical nipple –like
protuberance.
T. S.OF HYDRA PASSING THROUGH OVARY
1. Ovary is an ovoid structure located near the basal end of the body.
2. It is formed by the multiplication of the interstitial cells of the epidermis.
3. The multiplied cells get modified into primary oogonia
4. From the cluster of oogonial cells, one centrally located cell called oocytes
become larger and amoeboid with large nucleus.
5. The oocyte feeds on neighbouring interstitial cells and the reserve food is stored
in the form of yolk.
6. As a result of feeding, oocyte increases greatly in size and undergo two
maturation divisions.
7. Mature egg or ovum is a large spherical mass and occupies most of the space of
ovary.
8. The ovary is covered externally by epidermal cells.
9. Mature egg is partly exposed by the rupture of the covering epidermis and is
covered by a gelatinous protective sheath.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
ASCARIS MALE AND FEMALE
1. Ascaris
is
a
common
endoparasite in the small
intestine of man.
2. It is commonly known as round
worm.
3. Body is elongated, cylindrical,
pointed at both the ends.
4. Body is marked with mid –
dorsal, mid-ventral and two
lateral lines.
5. Mouth is situated at the
anterior end.
6. Posterior end of the male is
ventrally curved, having cloacal
aperture.
7. Through the cloacal aperture
two spicules project out,
known as penial setae.
8. Posterior end of the female is
bluntly pointed, having anus.
9. Excretory pore in male and
female is situated at the
anterior end just below the
mouth.
10. Female genital aperture or
gonopore lies about 1/3 of the
length of the body from the
anterior end.
11. Male is smaller than the
female.
12. Anus, in case of male opens
into the cloacal aperture.
CLASSIFICATION OF CHORDATES UP TO ORDERS
UROCHORDATA GENERAL CHARACTERS
1. Presence of nerve cord, notochord and gill slits.
2. Generally body is bilaterally symmetrical.
3. Presence of three germinal layers in embryonic condition.
4. Presence of post anal tail.
5. Closed blood vascular system.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
6. Presence of ventral heart and hepatic portal system.
7. Presence of well-developed Coelom.
8. Phylumchordata has two major divisions.a)Protochordata(Acraniata)b)Vertebrata
(Craniata)
HERDMANIA
PHYLUM: CHORDATA
SUBPHYLUM: UROCHORDATA
CLASS: THALIACEA
ORDER: PLEUROGONA
1. Commonly known as Sea squirt.
2. It is a solitary and sedentary ascidians found attached to rocks.
3. Body is divisible in to two parts: the distal free part of body proper and the base part
or foot.
4. Branchial siphon (mouth: Incurrent opening) and atrial siphon (excurrent opening)
at free end of the body.
5. Each aperture is guarded by four lips.
6. The basal foot is dirty in colour due to sand particles, shell pieces and other foreign
particles.
7. The entire body is covered by a thick, leathery, translucent protective covering called
test or tunic.
8. Presence of mantle containing a water filled cavity called atrium.
SALPA
PHYLUM: CHORDATA
SUBPHYLUM: UROCHORDATA
CLASS: THALIACEA
ORDER: PLEUROGONA
1. Salpa is typical pelagic form.
2. It is dimorphic and shows alternation of generation.
3. The solitary phase is asexual oozoid while gregarious phase is sexual gonozooid or
blastozooid.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
4. The sexual phase is bilaterally symmetrical with cylindrical body having branchial and
atrial aperture at opposite ends. The pharynx communicates on either side with the
atrium cavity through a large single gill slit. Pharynx with endostyle.
5. Oesopagus, stomach, intestine and pyloric glands forms a compact mass.
6. Heart midventral, behind the endostyle. Presence of eyespot.
DOLIOLUM
PHYLUM: CHORDATA
SUBPHYLUM: UROCHORDATA
CLASS: THALIACEA
ORDER: DOLIOLIDA / CYCLOMYARIA
1. It is a free swimming, pelagic form.
2. Life cycle includes a solitary sexual gonozooid phase alternating with a colonial or
oozoid phase.
3. Branchial and atrial apertures at opposite ends surrounded by 10-12 lobes.
4. The test is extremely thin and transparent.
5. The pharynx is perforated posteriorly by dorsal and ventral rows of gill slits.
6. Heart lies midventrally posterior to endostyle.
7. Sexes united, tests near the endostyle while ovary behind it.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
AMPHIOXUS
PHYLUM: CHORDATA
SUBPHYLUM: CEPHALOCHORDATA
CLASS: LEPTOCARDI
1. Amphioxus is also known as Branchiostoma and is found in shallow marine water.
2. Body is fish like, narrow, elongated, whitish, translucent, laterally compressed and
pointed at both the ends. Therefore called lancelet.
3. The greater anterior region is the trunk and posterior shorter post anal region is the
tail.
4. Anteriorly below the rostrum is a horse-shoe shaped structure called oral hood
surrounded by oral cirri, encloses mouth.
5. Atriopore is located in front of the ventral fin and anus at the base of the caudal fin.
6. Notochord is in the form of a stiff, elongated cylindrical rod like structure lying middorsally above the gut, and extends from the tip of the snout to the tail.
7. Myotomes a v shaped muscles on either side of the body.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
PETROMYZON
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CYCLOSTOMATA
ORDER: PETROMYZONIFORMES
1.
2.
3.
4.
5.
Commonly known as lamprey and is marine as well as freshwater.
It is externally parasitic, sucking blood of the host fishes.
Body is distinguished in to head, trunk and tail.
Head and trunk is cylindrical and tail is laterally compressed.
Anterior end bears a ventrally directed cup like sucker or funnel surrounded by oral
papillae lined by radiating rows of horny teeth.
6. The apex of the buccal funnel bears a small circular mouth opening behind which is
found tongue with large horny teeth.
7. Large prominent eyes; without eyelids.
8. Single nostril, seven pairs of external gill slits on lateral side of the head.
9. Cloacal aperture is located at the junction of trunk and tail.
10. Small sensory pores of lateral line system extend along the lateral side of the body
below the head.
MYXINE
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CYCLOSTOMATA
ORDER: MYXINIFORMES
1.
2.
3.
4.
5.
6.
7.
8.
9.
It is commonly known as hag fish and is exclusively marine in habitat.
Body is soft, scale less, elongated eel like and differentiated in to head trunk and tail.
Eyes are degenerate and covered with a thick skin.
Mouth is encircled by 6 cirri or tentacles.
Tongue is protrusible and is bordered by two serrated or multilobed horny plates
serves as a powerful rasping organ.
Single median nostril lies close to mouth.
Six pairs of gill pouches, located far behind the head but open outside by a single
pair of external gill slit.
Ventral fin and caudal fin is poorly developed.
Myxine attacks injured or dead fishes and burrows into their body to feed on flesh.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
DOG FISH
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CHONDRICHTHYES
ORDER: PLEUROTREMATA
1. It is the Indian dog fish shark with elongated spindle shaped and laterally
compressed body.
2. Body is divisible in to head, trunk and tail.
3. Two prominent eyes on each side of the head.
4. Ventral Crescentic mouth bounded by upper and lower jaw. Nostril ventral in
position.
5. Five pairs of external gill slits in the form of vertical clefts located behind the each
eye.
6. Two pairs of lateral fins- pectoral and pelvic; median fins are two dorsal, one caudal
and one ventral.
7. Exoskeleton is in the form of minute placoid scales arranged obliquely all over the
body.
8. A Cloacal aperture is located at the root of the tail and in between pelvic fins.
9. In males pelvic fins are modified in to rod like intermittent organ claspers.
HAMMER HEADED SHARK
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CHONDRICHTHYES
ORDER: PLEUROTREMATA
1. The body of the hammer – headed shark is elongated, stream lined.
2. Head is modified and is drawn laterally in the form of hammer-like and hence the
name.
3. Body is divisible in to head, trunk and tail.
4. Two prominent eyes on each side of the head.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
5. Ventral Crescentic mouth bounded by upper and lower jaw. Nostril ventral in
position.
6. Exoskeleton is in the form of minute placoid scales arranged obliquely all over the
body.
7. Five pairs of external gill slits in the form of vertical clefts located behind the each
eye.
8. First dorsal fin is larger, second dorsal is small and anal fin is opposite to second
dorsal.
9. Tail is heterocercal.
STING RAY
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CHONDRICHTHYES
ORDER: HYPOTREMATA
1. The body of sting ray is greatly flattened dorsoventrally and appears more of less
diamond-shaped.
2. Head and trunk constitute the body proper followed by a long whip-like tail
3. A pair of eyes are located mid-dorsally just behind the head.
4. Five pairs of gill slits located ventrally.
5. Mouth ventral and is always buried in the sand since they are bottom dwellers.
6. Pectoral fins are enormous and are joined laterally to the head and trunk. They are
used for swimming.
7. Pelvic fins are small found at the base of the tail.
8. Tail is long whip like and is usually provided with a poisonous sting and hence the
name.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
ELECTIC RAY
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: CHONDRICHTHYES
ORDER: HYPOTREMATA
1.
2.
3.
4.
5.
6.
The body of the electric ray is dorsoventrally flat and oval in shape.
It is divisible into body proper and tail.
A pair of large oval eyes located middorsally.
Five pairs of gill slits located ventrally.
Mouth is small, Crescentic and midventrally.
Pectoral fins are enormous and are joined laterally to the head and trunk. They are
used for swimming.
7. Pelvic fins are small found at the base of the tail.
8. Tail is broad and tapers gradually ending in single lobed tail fin.
9. A pair of electric organs is found dorsally on either side of the body.
LABEO
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: OSTEICHTHYES
ORDER: CYPRINIFORMES
1. It is commonly found in the fresh water ponds, lakes and river.
2. Body is divisible in to head, trunk and tail.
3. Mouth is sub terminal in the form of transverse aperture and bounded by thick
fleshy lips.
4. Two small threads like sensory maxillary barbells are present at the corners of the
mouth.
5. A pair of small nostrils dorsally on the snout.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
6.
7.
8.
9.
Large eyes without eyelids.
Fins are well developed and are supported by bony rays.
Body covered with overlapping cycloid scales.
Tail homocercal
EXOCOETUS
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: OSTEICHTHYES
ORDER: BELONIFORMES
1. Commonly known as flying fish.
2. Body is divisible in to head, trunk and tail.
3. Body covered with overlapping cycloid scales.
4. Tail homocercal.
5. Pectoral fins are modified in to wing like structure.
6. It takes leap with the power full tail and glides for a few meters in air with large
pectoral fin. True flight is not possible.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
SEA HORSE
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: OSTEICHTHYES
ORDER: SYNGNATHIFORMES
1. Head is large and right angle to body and appears like the head of horse hence the
name.
2. Mouth terminal, toothless and suctorial.
3. Body is covered with bony plates.
4. Pectoral fins are small, transparent and located behind each operculum.
5. Pelvic, ventral and caudal fins are absent.
6. Tail long prehensile and coiled.
7. Swims vertical with the help of vertical fins
8. Males with brood pouch on the belly for protecting eggs till hatching takes place
EEL FISH
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: OSTEICHTHYES
ORDER: ANGUILIFORMES
1.
2.
3.
4.
5.
Body of eel is slender elongated and snake like.
Skin with rudimentary scales.
Pectoral fins are small, behind operculum.
Pelvic fins are absent.
Dorsal and anal fins are continuous with caudal fin.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
ICHTHYOPHIS
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: AMPHIBIA
ORDER: GYMNOPHIONA
1.
2.
3.
4.
5.
6.
The body is long, slender, and wormlike with reduced tail, with terminal Cloacal.
Limbs are totally absent. Girdles are also absent.
The eyes are rudimentary, concealed and functionless.
A sensory tentacle is found in the groove between the eyes and nostril.
Skin is grooved with minute scales embedded in the groove.
The head is small and depressed.
FROG
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: AMPHIBIA
ORDER: ANURA
1. Body of frog is dorsoventrally flattened and is divisible in to head, trunk and limbs.
Neck and tail absent.
2. Skin of frog is smooth, moist slimy without any exoskeleton and is green with black
or brown spots with pale yellow ventrally.
3. External nares located dorsally on the tip of the snout.
4. Eyes large spherical and protruding with nictitating membrane at movable lower jaw.
5. Vestigial pineal eye called brown spot present just in front of eye.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
6. Presence of eardrum or tympanum behind and below each eye.
7. In males vocal sacs producing croaking sound during breeding season.
8. Cloacal aperture between the hind limbs.
TOAD
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: AMPHIBIA
ORDER: ANURA
1. The common Indian toad remains concealed during day but becomes active
during night.
2. It has no teeth in both the jaws.
3. The waist region is broad; hind limbs are shorter as compare to frogs.
4. The skin is rough, warty and provided with poison glands.
5. Ridges are found on the head. A raised poison secreting parotid gland is found
behind each tympanum.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
SALAMANDER
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: AMPHIBIA
ORDER: URODELA
1. Body of salamander is elongated, lizard-like.
2. Body is divisible into head, neck, trunk and tail.
3. Head more or less triangular bearing a pair of nares at the tip and a pair of small eyes
without eyelids.
4. Mouth is bounded with jaws with or without teeth.
5. Ear drum is lacking.
6. Trunk bears two pairs of limbs. They are almost equal but weak.
T. S. OF AMPHIOXUX THR PHARYNX
1. Dorsal fin ray and ventral metapleural folds give it a triangular shape.
2. Below the body wall there are segmental arranged muscle blocks or myotomes.
3. Pharynx being cut transversely it shows surrounding atrium, dorsal epipharyngeal
groove, lateral gill bars and gill slits and ventral endostyle.
4. Above the pharynx in the mid dorsal line there is notochord which forms axis of
body.
5. Above the notochord mid dorsally there is nerve cord.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
T. S. OF AMPHIOXUX THR INTESTINE
1. The T.S. is not triangular as that of pharynx.
2. Dorsal fin and ventral fin are seen in T.S. and hence T.S. is pointed both dorsally and
ventrally.
3. Intestine is cut transversely and hence round in shape.
4. Intestine is surrounded by atrium of lateral and ventral side.
5. Never cord and notochord are seen mid dorsally in a line one above the other as
shown in the diagram.
6. Myotomes are metamerically arranged and are surrounded by body wall.
T. S. OF AMPHIOXUX THR TAIL
1. The T.S. is round in the center but tapering both dorsally and ventrally.
2. Dorsal fin ray and ventral fin ray are pointed as shown in the diagram.
3. No part of alimentary canal in this region.
4. Myotomes are metamerically arranged and are surrounded by body wall.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
HOMOCERCAL TAIL
1. Homocercal caudal fin or tail fin is found in majority of higher bony fishes.
2. It represent the most advanced and common type of tail.
3. Externally it is symmetrical consisting of two equal lobes but internally it is
asymmetrical.
4. The two equal lobes of tail fin represent the original ventral lobe or hypo - chordal,
the dorsal lobe or epi - chordal lobe is suppressed.
5. Ventral column is short and its terminal part is slightly turned upwards into the
dorsal lobe.
6. The strokes of homocercal tail force he fish straight forward.
HETEROCERCAL TAIL
1. Heterocercal caudal fin is found in elasmobranches (sharks and rays) and bottom
feeders.
2. It represents the intermediate type of fin and is strongly asymmetrical.
3. The two lobes of fin are unequal externally as well as internally.
4. The ventral column bends upward and reaches up to the tip of the more prominent
dorsal lobe.
5. While swimming the strokes of the larger dorsal lobe serve to direct fish towards
bottom
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PRACTICAL HAND BOOK BSc I ZOOLOGY
GILLS OF CARTILAGENOUS AND BONY FISH
GILLS OF CARTILAGENOUS FISH
1. There are five pairs of gill pouches containing gills.
2. Adjacent gill pouches are separated from each other by the interbranchial or gill
septum.
3. The inner or pharyngeal border of each gill septum is supported by a cartilaginous
visceral arch or gill arch with its slender branchial rays.
4. The numerous membrane of a septum is raised into numerous horizontal leaves like
folds, called gill lamellae or filaments.
GILLS OF BONY FISH
1. There are four pairs of gill in bony fishes.
2. They are present on either side of the pharynx in common gill chamber.
3. Each gill consists of two rows (hemibranchs) of slender gill filaments'.
4. Inter branchial septum is extremely reduced so that the gill filaments hangs freely in
the gill chambers. Therefore this type of gill is called filiform or pectinate.
5. Every gill filament bears several minute transverse plates or lamellae covered with
thin epithelium containing capillaries.
The inner or pharyngeal border of each arch bears teeth – like processes called gill
rakers which prevent the entry of food particles entering the gill chambers
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PRACTICAL HAND BOOK BSc I ZOOLOGY
PLACOID SCALES
1. Placoid scales are characteristic of elasmobranches’ fishes only (Ex., Sharks and
Rays).
2. They are also called dermal denticles or odontodis.
3. They are embedded in the skin in regular oblique rows and from the exoskeleton.
4. A typical placoid scale consists of two parts: a rhomboidal basal plate and a flat
trident spine arising from its centre.
5. The basal plate is embedded in the skin while the spine projects out of the skin and is
backwardly directed.
6. The basal plate is formed by a bone like loose trabecular calcified tissue called
cement.
7. The trident spine is made up of a hard substance called dentine.
8. The spine has a central pulp cavity containing blood vessels, nerve endings, lymph
channels and dentine forming cells called odontoblasts.
9. Dentine is traversed by fine tubules of canaliculi.
10. Spine is externally covered by hard, shiny enamel like vetro dentine.
CYCLOID SCALES
1. Cycloid scales are found in lung fishes, some holosteans and lower teleosteans (e.g.
Labeo).
2. These scales are thin, flexible translucent plates.
3. They are circular in outline. They are embedded in the skin but overlap each other.
4. They are composed of upper layer of thin bone and lower layer of fibrous
connective tissue.
5. They are thicker in the centre and are marked with several concentric lines of
growth.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
MOUNTING OF VERTEBRATE BLOOD
1. I t is a special type of fluid connective tissue.
2. Blood shows two main parts - blood plasma and blood corpuscles.
3. Blood plasma is non living ground substance containing organic and inorganic
substances.
4. Blood corpuscles are of three types (a) Erythrocytes or RBC (b) Leucocytes or WBC (c)
Thrombocytes.
5. Erythrocytes are concerned with transport of gases.
6. Leucocytes are concerned with protection of body.
7. Thrombocytes are concerned with process of blood clotting.
DEMONSTRATION OF FROG
HEART OF FROG
1. Heart of frog is 3 chambered.
2. There are two auricles and one ventricle.
3. There are two more accessory chambers namely a dorsal sinus venosus and ventral
truncus arteriosus.
4. The sinus venosus is formed by the union of two pre-caval and a post caval.
FUNCTIONS
(i) Heart is a pumping organ. (II) It collects blood from body parts through
veins. (iii) it distributes blood to body parts through arteries. (iv)Thus, it brings about
efficient circulation of blood.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
DEMONSTRATION OF DIGESTIVE SYSTEM OF FROG
Digestive system consists of alimentary canal and associated glands.
Bucco-Pharyngeal Cavity:
1. The buccal cavity is bounded by upper and lower jaws.
2. The upper jaw has maxillary teeth which are acrodont, homodont and
polyphyodont.
3. The lower jaw is toothless.
4. Pair of V-shaped vomorine teeth project from the anterior part of the roof.
5. The openings of the internal nares occur on either side of the vomers.
6. The openings of the Eustachian tubes occur far back at the sides of the roof.
7. The glottis is slit like opening that leads in to the lungs. It occurs on the floor of the
buccal cavity.
8. In case of male frog openings of the vocal sacs at the sides on the floor of the buccal
cavity.
9. The gullet opening is large and leads to the oesophagus.
10. A sticky muscular tongue is attached in front and free behind. The free end is bifid.
FUNCTIONS OF THE BUCCOPHARYNX
i.
It serves as an insect trap with a shooting tongue.
ii. It helps in buccal and pulmonary respiration.
iii.
It helps male frog in croaking.
iv.
In bulging of eyes helps in swallowing food.
Alimentary Canal: It consists of Oesophagus, Stomach, Small Intestine, Large Intestine and
Cloaca.
1. Oesophagus: It is the muscular tube that extends between the buccal cavity and
stomach.
Function:
it carries food from buccal cavity to stomach.
2. Stomach: It is the hollow expansible muscular sac slightly curved on one side.
Anterior wider part is called cardiac stomach and the posterior narrow part is pyloric
stomach.
Functions:
(i) It stores food temporarily.
(ii) Food is partially digested in stomach.
3. Small Intestine: it is the tube connecting the stomach and large intestine. It is almost
of uniform diameter. It is distinguished into a duodenum and an ileum. The intestine
is suspended in position by a transparent sheet called mesentery.
Functions:
(i) Its internal lining produces intestinal juice.
(ii) It receives bile and pancreatic juice.
(iii) Food is completely digested in intestine.
(iv)The digested food is absorbed in intestine.
4. Large Intestine: It is also called rectum. It is an expanded, short and straight tube
connecting the small intestine and cloaca.
Functions:
(i) It stores undigested food temporarily.
(ii) It absorbs water from undigested food if required.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
(iii) It conveys fecal matter to cloacal chamber.
5. Cloaca: It is the posterior most chamber of the alimentary canal. It receives the
faecal wastes, urine and eggs (or sperms). It opens out as the cloacal aperture.
Associated Glands: These are two in number namely pancreas and liver.
6. Pancreas: it is a pale yellow digestive gland lying in the mesentery between stomach
and duodenum. It surrounds the bile duct and pours its secretion into it.
Functions:
(i) the islets of Langerhans of pancreas produce two hormones namely insulin and
glucagon. (ii) Exocrine part of pancreas produces pancreatic juice.
7. Liver: it is the largest digestive gland divided into three lobes. A thin walled sac called
gall bladder is associated with liver. It is connected to the duodenum by bile duct.
Functions:
(i) Bile is secreted by liver.
(ii) Excess glucose is converted into glycogen and is stored in liver.
(iii) Ammonia is converted into urea in liver.
(iv)Excess vitamins are stored in liver.
(v) Worn out R.B.Cs. are destroyed in liver.
DEMONSTRATION OF RESPIRATORY SYSTEM OF FROG
The respiratory organs of frog are pair of lungs, skin and buccopharynx. Frog respires with
the lungs, buccopharynx and skin when it is on land. In water, it respires with the help of
skin. Therefore frog can live both on land and in water.
Lungs and laryngotracheal Chamber
1. The paired lungs are thin walled, spongy and highly elastic sacs.
2. Lungs are suspended freely in the body cavity one on either side of heart.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
3. Externally each lung is covered by peritoneum called pleura.
4. Internally lungs are having alveoli and air chambers.
Functions: Atmospheric air is taken inside the lungs. Gaseous exchange takes place between
this and blood. Impure air is given out from lungs. Thus, lungs perform aerial respiration.
DEMONSTRATION OF EXCRETORY SYSTEM OF FROG
Kidney
I. A pair of kidneys is the main organs of excretion.
II. They are mesonephric, elliptical, dark red in colour.
III. They are located one on either side of vertebral column.
IV. Inner margin of kidney is lobulated and outer margin is smooth.
V. They remain attached to dorsal body wall.
VI. Functions (i) Excretion and osmoregulation. (ii) It also maintains PH of blood.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
OVARY OF FROG
1. Ovaries are lobulated female gonads.
2. There is a pair of ovaries attached to medial margin of kidney by mesovarium
ventrally.
3. The immature ovary is small yellow and semitransparent (seen on kidney).
4. The matured ovary is opaque and blackish in colour.
5. In gravid female it may occupy entire abdominal cavity.
Functions:
i. It produces the female gametes called ova.
ii. It also produces hormone estrogen.
TESTIS OF FROG
1. Testes are cylindrical, capsular
male gonads.
2. There is a pair of testes attached
to medial margin of kidney by
mesorchium ventrally.
3. Testis is creamy yellow or orange
in colour.
Functions:
i. It produces male gametes, the
sperms.
ii. It also produces androgen,
testosterone.
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PRACTICAL HAND BOOK BSc I ZOOLOGY
NERVOUS SYSTEM OF FROG
1. The brain is composed of three regions
a) Fore brain or prosencephalon.
b) Mid brain or mesencephalon.
c) Hind brain or rhombencephalon.
2. Fore brain consists of
a) Olfactory lobe (sense of smell),
b) Cerebral hemisphere (sheet of intelligence),
c) Diencephalon dorsally (provides nourishment to brain).
d) Infundibulum ventrally (hormonal regulation).
3. Mid brain consists of
a) Optic lobes (sense of sight or vision),
b) Crura-cerebri - thick nerve bands ventrally (communicates forebrain and hindbrain).
4. Hind brain consists of
a) cerebellum made up of five lobes (muscular control & static equilibrium)
b) Medulla oblongata (involuntary activities e. g. respiration, digestion, perspiration
etc.)
5. Spinal cord (Centre of spinal reflex actions and connects part of PNS to the brain).
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PRACTICAL HAND BOOK BSc I ZOOLOGY
SKELETON OF FROG
The skeleton of Vertebrate Is divided into
(a) Axial skeleton - includes skull and vertebral column.
(b) Appendicular skeleton – Includes girdle and limb bones.
ATLAS VERTEBRA OF FROG: 1. It is the first vertebra of frog.
2. Centrum is reduced.
3. Pre-zygapophyses are absent.
4. Pos-zygapophyses are present but small.
5. A pair of anterior concave facets articulates with the occipital condyles of skull.
AXIS VERTEBRA / SECOND VERTEBRA
1. It shows all the characters of typical vertebra expect transverse processes.
2. Transverse processes are winged.
TYPICAL VERTEBRA
From third vertebra to seventh all vertebrae of frog are considered as typical vertebrae
which show following characters.
1. Centrum shows concavity on anterior side and hence typical vertebra is procoelous.
2. Transverse processes are long and tapering.
3. Pre-zygapophyses are directed upward and inwards.
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