Digestive System in Pisces/Fishes

Digestive System in Pisces/Fishes

Digestive System in Pisces/Fishes

The process of breaking down of complex food into simpler forms with the help of various enzymes is known as digestion. The system that deals with with this process of digestion is known as digestive system .
Digestive system of pisces can be studied under  following  two headings:-

  1. Alimentary Canal
    Alimentary canal of vertebrates is a long ,straight or coiled tubular organ of varying diameter starting from the mouth and ending into either anus or cloacal aperture.
  2. Digestive Glands
    They are the glands which produce various chemicals and enzymes responsible for digestion of food. It basically consists of liver and pancreas.


Digestive system in Pisces/Fishes

  1. Alimentary Canal
    1. Mouth/Buccal cavity
      Mouth in pisces is present at the anteriormost part or terminal part  or it may occur ventrally. It is surrounded by immovable and cornified lips. It is immediately followed by a wide buccal cavity.
      Buccal cavity usually consists of structures like teeth and tongue.Teeth in many fish are just responsible for preventing the prey form escaping  out from the buccal cavity and the fish belonging to family Cyprinidae (carp fish ) lacks teeth in their buccal cavity and teeth if present are of homodont and polyphyodont type.
    2. Pharynx
      Pharynx in fishes is a short tubular organ which on either side consists of opening of gills for aquatic respiration. Fish like labeo rohita (rohu) consist of teeth in their pharynx.
    3. Oesophagus
      Oesophagus in fish is also short due to the absent of neck but it is expandable as a result they can swallow large food. It simply conducts the food towards the stomach.
    4. Stomach
      Stomach in them is a wide tubular organ differentiated into anterior cardiac stomach and posterior pyloric stomach. Stomach in chondrichthyes consists of a number of gastric glands but such glands are not present in the stomach  of osteichthyes and in them stomach just help in temporary storage of food.
    5. Intestine
      Intestine is the main part of the alimentary canal where the digestion of food and absorption of digested food  take place. Intestine in chondrichthyes is completely short , straight and wide and it is provided with a number of  valves which delay the passage of food. Intestine in osteichthyes is very much elongated, coiled and narrow and is divisible into anterior small intestine and posterior large intestine.
    6. Anus/Cloacal Aperture
      Anus and cloacal aperture are the openings of intestine through which the undigested food materials are passed outside . anus is present in osteichthyes but chondrichthyes have cloacal aperture.
  2. Digestive Glands
    • Liver
      Liver in  fish is narrow, elongated and cylindrical in shape. It is usually bilobed in chondrichthyes and trilobed in case of osteichthyes. Liver produce bile juice for emulsification of fat. Emulsification is the process of conversation of larger molecule into smaller molecules.
    1. Pancreas
      Pancreas in chondrichthyes is comparatively less developed than osteichthyes. In chondrichthyes , pancreatic cells are few and are found scattered  in the mesenteries  near by the stomach. In osteichthyes pancreas is found in the loop between stomach and intestine. Pancreas secrete pancreatic juice containing various enzymes to digest food.

#alimentary canal#digestion#digestive glands#digestive system#fish#fish digestion#pisces