4. ANIMAL KINGDOM
PHYLUM PLATYHELMINTHES (FLATWORMS): GENERAL CHARACTERS
- Grades of organization:
- Organ & Organ system.
- Symmetry:
- Bilateral symmetry.
- Germ layers:
- Triploblastic.
- Coelom:
- Acoelomate
- Habit and habitat:
- Mainly aquatic. Endoparasites.
- Some are free-living.
- Digestive system:
- Incomplete.
- Respiratory system:
- Absent
- Circulatory system:
- Absent
- Reproduction:
- Asexual (fragmentation) and Sexual.
- Hermaphrodite.
- Internal Fertilization.
- Development is indirect.
- Many larval stages.
- Unique features:
- Unsegmented,
dorso-ventrally flattened body (except tape
worms).
- Excretion and osmo-regulation by Flame cells.
- Parasites have Hooks & suckers.
- Some absorb nutrients from the host through their body surface.
- Examples:
- Taenia solium (Tape worm)
- Fasciola (Liver fluke)
- Planaria (shows high regeneration capacity).
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👇 Select Your Topic Here 👇
- Topic 1: Basis of Classification
- Topic 2: Porifera
- Topic 3: Cnidaria
- Topic 4: Ctenophora
- Topic 5: Platyhelminthes
- Topic 6: Aschelminthes
- Topic 7: Annelida
- Topic 8: Arthropoda
- Topic 9: Mollusca
- Topic 10: Echinodermata
- Topic 11: Hemichordata
- Topic 12: Chordata - up to Sub phylum Vertebrata
- Topic 13: Chordata - Cyclostomata, Pisces
- Topic 14: Chordata - Tetrapoda
