Question

Does cnidaria have a digestive system?

Answer 1

Hint: Cnidaria is a phylum which comes under Kingdom Animalia. They consist of mostly aquatic animals that are found in marine environments and freshwater environments. The most distinguishing feature of Cnidaria is the presence of cnidocytes that they use to capture prey.

Complete answer:
Cnidaria are diploblastic animals having radial symmetry. Cnidarians are known to have two body forms- the sessile polyps and the swimming medusae. Cnidarians are known to feed in different ways such as parasitism, predation, filtering food particles from water, utilizing algae to obtain food and absorption of dissolved organic matter. The digestion of food in case of cnidarians occurs both intracellularly and extracellularly. The digestive system of cnidaria is complete; it consists of one opening that serves both as the mouth and the anus. Once the food reaches the digestive cavity popularly known as the gastrovascular cavity, the gland cells release enzymes to make the food slurry. This food then circulates throughout their body so that they can be acquired by absorption. Circulation of the food takes place by the help of water currents. Absorption might take a few hours and subsequent digestion a few days. Undigested materials produced after digestion are expelled out of their mouth.

Note-
One of the most important roles played by cnidarians is the formation of coral reefs. They not only help in the protection of beaches from storms and tides but also provide fishing grounds. Some of the coral reefs are also very famous tourist spots. But a few of them such as jellyfish, can be harmful too.