Animal Kingdom
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Coelom
Coelomate
Coelomate
Coelomate
Habit and
habitat
Aquatic, few are
terrestrial
Exclusively marine
Marine
Digestive
system
Complete
Complete
Complete
Respiratory
system
Gills in aquatic forms
and pulmonary sac in
terrestrial forms
Dermal branchiae
(skin gills or papulae)
and tube feet
Gills (NEET 2017)
Circulatory
system
Open type
Reduced and open
type.
Open type
Reproduction
Dioecious, oviparous,
development is
indirect
Dioecious, external
fertilisation,
development is
indirect, ciliated free-
swimming larva
Dioecious, external
fertilisation,
development is
indirect
Unique
features
Body has head,
visceral mass
(visceral hump)
and mascular foot,
head has sensory
tentacles, univalve or
bivalve calcareous
shell, feather-like
gills for respiration &
excretion, mantle &
radula are seen.
Body is covered
with spines for
protection, head is
absent, calcareous
endoskeleton
(ossicles) present,
water vascular system
present, excretory
system absent,
shows autotomy &
regeneration.
Worm-like
cylindrical body
composed of
an anterior
proboscis, a collar
and a long trunk,
proboscis gland.
Examples
Pila (Apple Snail),
Pinctada (Pearl
Oyster), Sepia
(Cuttlefish), Loligo
(Squid), Octopus
(Devil fish), Aplysia
(Sea Hare),
Dentalium (Tusk
shell), Chaetopleura
(Chiton)
Asterias (Starfish),
Echinus (Sea Urchin),
Echinocardium,
Antedon (Sea Lily),
Cucumaria (Sea
Cucumber), Ophiura
(Brittle Star)
Balanoglossus
(Tongue worm),
Saccoglossus.
1.
Mollusca is the second largest phylum.
2.
Radula: File-like rasping organ present in the mouth of molluscs. It is
used for feeding.
3.
Mantle (Pallium): The membrane which covers visceral mass. Space
between the hump and mantle is called mantle cavity.
4.
Water vascular (ambulacral) system: In this system, sea water enters
through a porous plate called madreporite and reaches the radiating
canals and tube feet (podia). Its functions are locomotion, respiration,
food capture & transport.