Q. 2. Give an account of the receptor organs in Aurelia and describe its mode of feeding.
Mode of Feeding
Aurelia is exclusively carnivorous and the food consists of chiefly small invertebrates such as crustaceans, worms, etc.
The food is caught by the oral arms and tentacles. The nematocysts present in them paralyze and entangle the prey. It is finally swept through the grooves on the oral arms to the mouth. The nematocysts of the gastric filaments also paralyze and kill the prey.
The digestion of food occurs inside the stomach and gastric pouches. The endoderm cells of the gastric filaments and stomach liberate digestive enzymes which mix with the food and bring about intracellular digestion. The partly digested food, broken into small fragments, is swept into the canals by the beating of cilia along with the gastrovascular fluid.
These particles are picked up by the endodermal cells of the canals and are converted into food vacuoles where intracellular digestion is facilitated. Proteins, fats, and carbohydrates are said to be digested. The digested food circulates through the gastrovascular system along with the water current and is carried through the unbranched adradial canals to the circular canal.
The undigested food returns through the inter-radial and per-radial canals back to the gastric pouches and ultimately to the exterior through the mouth. It passes along the exhalent grooves on the oral arms. The digested food is picked up and distributed by the wandering amoebocytes.
BSc 1st Year Lower Non-chordates Aurelia Sample Model Practice Question Answer Papers