1. Biology and Physiology
of
Pomacea Canaliculata
Presented by
CHANG PEI XIAN D 20101037455

2. Pomacea Canaliculata are amphibious, both
in physiology and behaviour.
Their mantle cavity contains both a ctenidium
(gill) and a portion modified as a pulmonary
sacs or “lung”.
have gills, but can survive for extended
periods exposed to air.
Have a trap door (operculum) to protect their
soft tissues when withdrawn into the shell.

3. Coloration of the shell is brown or olive
brown, often with darker bands and blotches.
Show sexual dimorphism in shell size, shape,
thickness and weight.
They have been reported to change sex. Sex
change is from male to female (during a period
of without aestivation)
Shows variation related mainly to different
thermal regimes.

4. Pomecea Canaliculata have long life cycles
(>3 years but depends on the thermal regimes).
 Iteropareous in regions with hydric and
thermal seasonality.
When reared at a constant temperature of
25 C, P. Canaliculata’s life span reduced to
less than 14 months.
Growth is not continuous but seasonal.
 temperature appears to be the main factor
affecting both the maturation process and their
activity.

5. Sexually mature when it is 25 mm.
Able to tolerate low levels of salinity.
Experimental traits have shown that growth
rates, longevity and age at maturity are highly
dependent on temperature, crowding and food
availability.
Mobility and feeding are highly reduced when
water depth is lower than shell
diameter, drought survival is probably related
to size.

6. Anatomy of Pomacea Canaliculata
Male Snail

7. Female Snail

8. Digestive System
 The digestive system of Pomacea Canaliculata is
adapted to feed on aquatic plants.
 It can be divided in five regions:
The intake region
(mouth and buccal cavity with radula and jaws)
The pre-digestion region
(esophagus with salivary glands and lateral pouches)
Digestion region
(3 chambered stomach with associated digestive glands)
Uptake region
(intestine)
The excretion region
(rectum and anus)

9. Scheme of the Digestive Tract

10.  Mouth
vertical slit opening, located between the labial
tentacles and leading to the buccal cavity.
Food is located with the labial tentacles and when
needed gathered from the water surface with foot.
The radula of an eating snail in The radula knobs and jaws of an eating
Detail(Pomacea Canaliculata) Snail(Pomacea Canaliculata)

11. Buccal cavity
A muscular cavity with a set of calcareous
jaws, 2 radula knobs and the radula (rasp
tongue), is situated behind the mouth opening.
When the radula is bend and stretched, this
spreading the teeth on it, which provides the
grasp function.
After the food has pulled into the buccal
cavity, calcareous jaws cut off the piece of food.

12. Stomach
A pink “U” shaped structure on the left side of the
body whorl.
Consists of three compartments:
◦ the muscular gizzard (posterior chamber)
◦ the vestibule (anterior chamber)
◦ the style sac.

13. Intestine
Lies close to the style sac and coils around the
posterior kidney.
Can be divided in several parts: the caecum, the
first, second and third part of the intestine and anal
papilia.
The digestion of the food is partially done by
adding enzymes by the snail itself and partly by the
micro-organisms in here.
The uptake of the food compound is carry out
through the walls of the intestine and transported to
the blood stream.

14. Sensory System
Pomacea Canaliculata are highly dependent
on their smell sense.
Able to locate food and recognize other snails
of their own species with their smell sense.
Vision is weak; functions merely as a light
direction detector.
The tactile sense is well developed.
The hearing capabilities are worthless, even
more, they are completely deaf.

15. Body:
the whole body surface contains chemo- and
mechanoreceptors.
Eyes:
The eye on the eye stalk of a Pomacea Canaliculata Snail.
The eyes of the Pomacea Canaliculata are located
at the base of the tentacles, on top of the eyestalks.

16. The structure of the eye does not provide
detail vision, they rather function as
directional light sensors.
Colour vision is absent; Pomacea
Canaliculata is colour-blind.
Two mechanisms are used in their eyes to
increase sensitivity to light: the eyes are
relatively large with a large lens and the light
sensitive cells (rhabdoms) are grouped and
connected with the same neuron.

17.  Osphridia:
A chemosensory structure that is located in the mantle
cavity, in front on the lung.
Gives the snail capability to smell chemical substances
in the water.

18. Statocysts:
Function as balancing organs, used by the
snail to detect its position with regard to the
ground.
Located inside the snail’s body closed to the
pedal ganglia.
Tentacles:
Important sensory organs.
Pomacea Canaliculata highly rely on the
smell capacity and the sensitivity of their
tentacles to navigate in their environment.

19. Nervous System
Central nervous system consists of a several
ganglia connected with each other by a
commisura.
The perikaya (cell bodies of the nerve cells)
are concentrated in these ganglia.
Some parts of the nervous system are
symmetric while others are not.
There isn’t a central brain in snails like
mammals have.

20. Scheme of the Nervous System

21. Respiratory System
The respiratory system of the Pomacea
Canaliculata : a combination of a gill and a
lung.
The arise of the lung in Pomacea Canaliculata
can be explained by the following conditions:
Low oxygen level in the tropical pools.
Use during periods of drought.
Increases the action radius of the snail.

22. Retained their gill during the course of
evolution, this is contrary to the Pulmonata
snails, which only have a lung and no gills.
Having a gill provide a big advantage - can
avoid attacks by the land predators.
Have a siphon (breathing tube) so that they
can breath air while staying hidden below the
surface.

23. Description of the Respiratory Organs
Ctenidium:
Gill of the Pomacea Canaliculata.
Consists of a row of gill filaments that hang
into the mantle cavity.
Osphradius:
Smell organ of Pomacea Canaliculata.

24. Lung:
An air filled sac in the left mantle cavity.
Walls of the pulmonary sac are well supplied
with blood to exchange oxygen and carbon
dioxide.
Siphon:
An organ consisting of a fold of the mantle
cavity.
Enable the snail to breath air while staying
submerged.

25. Heart and Circulation
There is only one auricle that receives oxygen
rich blood from the lung and gills,
deoxygenated blood from kidney.
No separated blood circulation for oxygen rich
and deoxygenated blood.
Blood has two functions:
As hydroskeleton(structural support).
Transport of O2, CO2, hormones, nutrition and
waste products.
Open circulation.

26. H = Head - cephalic hemocoel Au = Auricle
F = Foot hemocoel V = Ventricle
E = Oesophagus Aa = Aorta anterior
Vm = Visceral mass (hemocoel) Ap = Aorta posterior
aK = anterior (front) Kidney Vs = Visceral sinus
pK = posterior (back) Kidney Fs = Foot sinus
A = Ampulla

27. The transport of the blood to and from the
organs occur through artery.
They don’t have capillary veins and arterioles.

28. Reproductive System
Has separated sexes (dioecious).
The differences between the sexes are not
visible at shell colour or pattern.

29. Male reproductive system
 The male reproductive tract consist of the testis
and vas deferens, the seminal vesicle and the
prostate gland, the penial sac, the penis and the
penis sheath.
 During mating activities, this penial papilla bends
towards the sperm groove in which the sperm is
conducted.
 The sperm is conveyed in the penial duct at the
base of the penis.
 On erection the penis comes out of the penial sac
and is grasped around on the lower part by a
muscular penial sheath from the mantle.

31. Female Reproductive System
The egg cells are stored in the ovaries.
To produce an egg, the egg cell is brought to
the receptaculum seminis. In this place, the
fertilization of the egg cells takes place.
The spermatozoa (sperm cells) of the male can
survive for more than a month in the
female, and several egg clutches can be
fertilized with a single copulation.
The eggs were deposited above the water line.