🦐Digestive system comprises the alimentary canal and a complex digestive gland called hepatopancreas .
🦐Alimentary canal has three divisions, namely stomodaeum or Fore gut,mesodaeum or Mid gut and proctodaeum or hind gut.
🦐Stomodaeum (fore-gut) consists of mouth, buccal cavity,
Oesophagus and stomach.
🦐Mesodaeum (mesenteron or mid-gut) includes the intestine.
🦐Proctodaeum (hind-gut) consists of the rectum and anus.
🦐Stomodaeum and proctodaeum
has internal cuticular lining, called intima.
🦐Mesodaeum has endodermal lining.
🦐Mouth is a longitudinal -slit guarded in front by a chitinous plate, called labrum, on the sides by the mandibles, and behind by the bilobed labium.
🦐Buccal cavity is a short and compressed chamber.
🦐 Its cuticular lining is irregularly folded.
🦐Running vertically upward from the buccal cavity to the stomach, is the oesophagusts
🦐Stomach is a spacious chamber.
🦐It fills most of the cephalo-thoracic region.
🦐It has two unequal divisions, large cardiac stomach and small pyloric stomach.
🦐Cardiac stomach mainly serves for the storage and grinding of the food, and the pyloric stomach is mainly concerned
with sorting and straining.
🦐On the floor of the cardiac stomach there are numerous cuticular folds, armed with setae and spicules.
🦐Dorso-laterally, its cuticular lining bears numerous stoutand tooth-like denticles.
🦐These serve as an internal masticatory apparatus, often called the gastric mill or gastric armature, for grinding the food.
🦐The cuticular lining of the pyloric
stomach is produced into four longitudinal folds, known as lappets or valvulae.
🦐One of them is dorso-median, one ventro-median, and the others lateral.
🦐These extend backward to the
mid-gut, incompletely dividing the pyloric chamber into compartments.
🦐Pyloric stomach has a filtering apparatus, formed of chitinous plates and comb-like bristles.
🦐The proctodaeum is the posterior region of the alimentary canal.
🦐It consists of the hindgut (or rectum) and the anus.
🦐The anus lies at the base of the telson ventrally.
🦐Digestive gland :
The digestive gland consists of a massive hepato-pancreas or liver.
🦐It lies in the cephalothorasic region.
🦐The digestive secretions of this gland reach the mesenteron by a pair of openings.
🦐 *Food and feeding:*
🦐Penaeus feeds on small marine algae, other vegetation, small insects, etc.
🦐The chelate legs collect and pass the food material towards the mouth.
🦐The mandibles cut the food into small pieces.
🦐The maxillae and maxillipeds aid in swallowing the food.
