VPP 322: Aquatic Animal Diseases, Health Care and Management (1+1)

INTESTINE AND PYLORIC CAECAE 

Intestine 

• It is a coiled tube lying between stomach and anus.
• The proximal part of the intestine is duodenum, the middle is illum and the distal end is rectum
• It cannot be extremally demarcated into different parts. However, there is a difference in the disposition of the mucus folds.
• The length of the intestine varies in different species. It varies from 1/5 to 20 times of the body length. It is short and nearly straight in carnivores but long thin walled and highly coiled in herbivores. Omnivores show an intermediate condition.

Pyloric caecae (Intestinal caecae)

• They are the finger like outgrowths located at the junction between the stomach and intestine
• Not all fishes have intestinal caecae
• Number of caecae varies from 1 to 1000 (catfish and minnows lack caecae: bichir – 1; yellow perch 3; salmon and mackerel-200)
• Its function is to increase the digestion and absorption area
• Trypsin is secreted in the pyloric caecae in some species