This document provides details about the sensory organs, reproductive system, and development of the freshwater snail Pila. It describes the osphradium, statocyst, eyes, and tentacles as sensory organs. The reproductive systems of both male and female Pila are examined, including testes, vas deferens, penis, and ovaries. Fertilization occurs internally in the uterus, and eggs are laid in masses. Larval development involves a trochophore stage followed by a veliger larva.

1. GUIDED BY – Dr. Poonam Sharma Made By –
Kuldeep Gauliya

2. PROJECT ON
DETAILED
STUDY OFPila

3. ACKNOLEDGEMENT
I TAKE THIS APPORTUNITY TO
EXPRESS MY PROFOUND
GRATITUDE, DEEP APPRICIATION
AND SINCERE THANKS FOR
PROJECT SUPERVISION.
I WANT TO GIVE ALOTE OF
THANX TO Mrs. POONAM
SHARMA Mam BECAUSE
WITHOUT HER GUIDENCE THIS
ZOOLOGY PROJECT HAVE NOT
BEEN COMPLETED.

4. SENSE ORGANS OF
Pila
• Pila have special organs of sense.
• It consists of these organs :-
(A) A single
osphradium
(B) Paired eyes
(C) Statocyst
(D) Tentacles

5. A.
OSPHRADIUM
• Osphradium hangs from the
mentle near the
pseudodipodium.
• It is oval with 22 to 28 fleshy
leaflets arranged on the sides of
central axis.

6. B. STATOCYST
• Located in the foot near each pedal
ganglion like a statocyst in
depression.
• It is a round capsule lined with
epithilial cells and surrounded by
connective tissue.
• The statocyst receive the nerves
from pedal & cerebral ganglia, they
are the organs of equilibirium and
regulate the position of the snail.

7. C. EYES
• An eyes is an oval capsule, its
wall is the ratina made of
pigmented sensory cells, it is
continued in front as a thin, non
pigmented, transparent cornea.
• An opotic nerve innervates the
ratinal cells.
• Eyes are sensory to light.

8. D. TENTACLES
• The tentacles and foot are
liberally supplied with nerves,
they are sensory to contacts,
tentacles contains both tactile
and chemoreceptor cells and
probably gustatory also.
• The first pair of tentacles are
olfactory.

9. REPRODUCTIVE
SYSTEM
• In Pila sexes are separate, i.e.
dioecious and there is a definate
sexual dimorphism.
• The shell of the male is smaller in
size and less swollen then the
female.
• There is a well develop copulatory
organ in the male but it is quit
redimentary in the female.

10. MALE
REPRODUCTIVE
SYSTEM• The male reproductive system
consist of 1. Testis with fine vasa
efferentia, 2. Vas deferens with the
vesicula seminalis and the terminal
glandular part of the vas deferens,
3. panis with its sheath and, 4.
Hypobranchial glands.

11. TESTIS
• It is the flate plate like whitish
structure,more or less triangular in
outline situated in the upper part of
the first whorls of the shell.
• The cream colored testis is easily
distinguished from the from the
digestive gland which is brownish or
dirty green.
• Minute ducts the vasa efferentia
lead downwards from the different

12. parts of the testis and may unite with
one another before opening into vas
deferens.

13. VAS DEFERENS
• From the posterior end of testis
arises a thin vas deferens.
• It consist of three distincts parts:-
1. Proximal thin tubular portion
leading from the testis.
2. Vesicula seminalis,
3. Thick glandular portion which
opens into the mantal cavity near
the anul opening.

14. # The vesicula seminalis open on the
left side into the terminal glandular
part of the vas deferens.
# In the mantal- cavity, the vas
deferens lies closely attached to
the left side of the rectum and the
ends in a prominent claw – shaped
structure the genital papilla having
the male genital aperture a littile
behind the anus.

16. PENIS SHEATH AND PENIS
• The edge of the mantal bears on its
inner surface a thick glandular flap
of a yellowish color.
• The flap is attached on its right-side
but is free on its left ; edge slightly
rolled in to from s spout – like
sheath.
• The penis is capable of extension.

17. HYPOBRANCHIAL GLAND
• At the base of the penis sheath is
an oval hypobranchial gland.
• It consist of of tall cells containing
small nuclie.

18. SPERMATOGENESIS
# The spermatogenesis of Pila
globosa has been worked out by
Sharma, G.P, Gupta, BrijLal, and
Mital,O.P. (1959) and they have
reported that the spermatozoa of
Pila are of two kinds :-
(1) Eupyrene sperm
(2) Oligopyrene sperm

19. 1. EUPYRENE
SPERMS
• The eupyrene sperms are hair like having
and elpongated spiraly twisted nucleus
with a small conical acrosome in front,
and a mitochondrialmiddle piece behind,
followed by the end piece in the form of a
long vibrating tail.
• These sperms moove actively forward in
the spiral course, measure about 25 µ in
length and 1.2 µ in breadth and they can
only fertilise the eggs.

20. OLIGOPYRENE
SPERM
• The oligopyrene sperm on the other
hand, have a very sluggish and
serpent – like movement.
• Ther acrosome is poorly developed,
the nucleus is elongated, broad
curved but but spirally coiled ; the
middle piece is short and the no. of
axial filaments varies from 4 – 8.
• These are probably having some
secondary function.

21. FEMALE REPRODUCTIVE
SYSTEM
The female reproductive
system is consists of 1.
Ovary with numerous
minute ducts, 2. main
oviduct, 3. receptaculum
seminis, 4. uterus,
5.Vagina and, 6.
Hypobranchial gland.

22. 1. OVARY
• The ovary in the female lies in the
same position as the testis in the
male but it is not so extensive.
• Ovary is much branched structure of
a light orange color which become
Darker in fully matured individuals.
• The branches of ovary consist of
single layered acini which are more or
less flask – shaped.222

23. 2. OVIDUCT
• The narrow and transport oviduct
originates from about the middle of
the ovary.
• It runs anteriorly just below the skin
along the inner margin of the
digestive gland.
• Near the renal organ it turns
downward and then upwards to
enter the receptaculum seminis.

24. RECEPTACULUM
SEMINIS
• It is a bean shaped structure.
• A thin walled pouch arises directly
from the wall of the uterus and is
called the pouch of the
receptaculum.

25. 4. UTERUS
• It is a large pear shaped structure,
deep yellow in color.
• It lies inside the inside the body whorl
below the intestine and the right of the
renal chambers.
• The apex of the uterus points forwards
and is continued as the vagina, while
its basal portion is broad and rounded
and is connected on its outer side with
the receptaculum seminis

26. 4. VAGINA
• The vagina is the white or cream
colored, band like structure laying
immediately beneath the skin.
• It extends from the uterus to the
upper end of columellar muscle.The
vagina enters the mantle cavity at
its right posterior corner and
continues farwads to the female
genital apereture situated on the
smaal papilla, a little behind the
anus.

27. 6. HYPOBRANCHIAL GLAND
• The hypobranchial cavity of
the female is poorly
developed.
• There is a rudimentary
glandular thickning in the
area of the hypobranchial
gland.

28. 7. COPULATORY APPARATUS
• The female is the rudimentary
penis laying beneath the
glandular fold at the edge of
the mantal.
• There is no trace of the
foldings of the penis sheath.

29. FERTILESATION
• Eggs are fertilised in the uterus
and oviposition starts a day or
two later.
• The fertilised eggs are laid in
masses of 200 to 800 in moist
earth near pond and lakes.

30. DEVELOPMENT
• In development mollusca passes
through two larval stages, there is a
trochosphere larva which soon
grows into veliger larva.
• A free swimming trochosphere is
found only in some ptimitive
gastropodes, such as Diotocardia,
but in all others the trochosphere
stage is reduced and passed within
the egg.