Introduction

• Digestive system consists of alimentary canal and its associated glands.
• The digestive tube also contains numerous intramural glands which provide the tube by lubricating mucus, enzymes, water etc.
• While extramural glands are liver, pancreas and gall bladder
• On the basis of feeding habits, the fishes are categorized as follows:

1. Herbivorous
2. Carnivorous
3. Omnivorous
4. Plankton Feeder or Detrivorous