7. Class 1: Polychaeta
Bundles of Setae
Marine and Carnivorous
Body elongated and Segmented
Each segments has pair of Parapodia
Clitellum absent
Sexes separated
Fertilization external
Eg(Neres),(Serpula).
8. Class 2: Oligochaeta
Setae arranged individually
Mostly terrestrial and some species freshwater forms
Parapodia absent
Clitellum present
Hermaphrodites
Development is direct- Cocoons
Free larval stages is absent
Eg( Tubifex), (Megascolex)
9. Class 3: Hirudinae
Ecto parasite
Dorso ventral flattened body
Parapodia and Setae Absent
Body provide Posterior and Anterior Suckers
Hermaphrodite
Reproduction Sexual
Egg usually laid cocoons
Eg (Leech), (Glossiphonia)
10. Class 4: Archiannelida
Exclusively marine forms
Body elongated and worm like
Setae and Parapodia absent
Prostomium bears two or Three tentacles
Unisexual or Hermaphrodite
Larva is Trochophore
Eg (Polygordious), (Nerilla)
11. Class 5: Echiuroidea
Marine found Mud and Sand
More or less Cylindrical
Anus is terminal
Parapodia absent
Coelom is large and Undivided
Sex are separate
Larva is Trachophore
Eg (Echiurus), (Bonellia)
12. Class 6: Sipunculoidea
Marine found Mud and Sand, Coral in Boring sea shore
Body elongated Yellow or Greenish Colour
Parapodia and Setae Absent
Anus placed in Dorsal surface
Coelom is Spacious and Undivided
Sex are separate
Larva is Trachophore
Eg (Sipunculus), (Phascolosoma)
13. Class 7: Priapulida
Marine found Moderate depths, Burrowing in Sand
Body Cylindrical, worm like unsegmented
Mouth Anterior Anus Posterior
Short introvert without oral Tentacles
Sex are separate
Development in Unknown
Eg (Priapulus)
14. Class 8: Myzostomaria
Live as ecto and endo parasite specially Crinoids
Body unsegmented , flat and oval disc like shape
Five pairs of Parapodia with acicula and hooks present
Four pair suckers
Ten pair Cirri
Circulatory and Respiratory system absent
Single pair Nephridia
Larva is Trochophore
E.g (Myzostoma)
16. Class 1: Merostomata
Aquatic and Marine
Abdominal appendages are modified into gills.
Abdomen ends in a Telson
Lateral compound eyes are present
Eg(Limulus)
17. Class 2: Arachnida
Air breathing, Mostly terrestrial arthropods.
Body two regions Cephalothorax and Abdomen.
Antennae and true Jaw absent
Respiratory organ varied – Terrestrial Tracheae and
Book lungs, Aquatic Gill and Book Gill
Excretory organ – Malpighian tubles or Coxal gland
Sex separated
Eg( Scorpion)
18. Class 3: Crustacea
Aquatic and Marine, Few live in moist
Body covered Chitinous cuticle
Triploblastic- Body divided into Head, Thorax,
Abdomen.
Respiration – Gill
Excretory organ- Green glands
Sex separated- Dimorphism
Development- Metamorphosis
E.g , Lobsters
19. Class 4: Myriapoda
Air breathing arthropods
Body elongated numerous segments
Head distinct bearing many joined antennae, a pair of
eye
Reparatory organ are tracheae
Excretory organ one or two pair of Malpigion tubules
Sex separated
Eg(Millipedes and Centipedes)
20. Class 5: Insecta
Air breathing mostly Terrestrial and Rarely aquatic
Body divided into three- Head, Thorax, Abdomen
Liver is absent but Salivary gland
Respiration by branched trachea
Excretion is malpighian tubules
Sex separate
Development metamorphosis
E.g(Rhinoceros beetle)
22. Class 1: Aplacopora
Body is Worm like, Bilaterally symmetrical and
Cylindrical
The head, mantle, foot, shell and nephridia are absent
The Body covers spicule bearing cuticle
Digestive track is straight with radula
Eg( Neomenia), (Chaetoderma)
23. Class 2: Monoplacopora
Body is bilaterally symmetrical and segmented
Shell is formed of a single valve
Head without eyes and tentacles
Gill are external and serially arranged
Nephridia are five pairs
E.g(Neopilina galatheae)
24. Class 3: Polyplacopora
Bilaterally symmetrical, dorsoventrally flattened
Shell is composed 8 plates
Foot is flat and ventral
Radula well developed
Eg(Chiton),(Cryptochiton)
25. Class 4: Gastropoda
Gastro- Stomach, Poda- foot
Unsegmented and Asymmentrical
Shell is univalved and Spirally coiled
Respiration Gills and Lungs
Visceral mass is turned through 180 by Tarsion
Circulatory system is open
Hermaphrodite
Eg( Natica), (Pila)
26. Class 5: Scaphopoda
Foot is boat shaped
Shell tubular opening at both ends
No Head
The eye, tentacles and Ctenidia absent
Marine, bilateral
Tusk shells
Eg( Dentalium), (Pulsellum)
27. Class 5: Pelecypoda
Bilateral symmetrical
Bivalvia
Head absent
Mentle formed two lobes
Radula absent
Respiration – Gill
Sexes are separated
Eg( Mytilus),(Pecten)
28. Class 6:Cephalopoda
Foot modified into funnel, tentacles present around
mouth
Bilateral symmetry
Visceral mass not coiled
Respiration – Gill
Two pair Kidney
Sex are separate
Development direct
Eg( Loligo),(Sepia)
