Where coelenterates digest food: features of physiology

Freshwater hydra, jellyfish and coral polyps are typical coelenterates, which are multicellular. What kind of lifestyle do they lead? What do they eat? Where do Coelenterates digest food? The answers to these and many other questions can be found in our article.

General characteristics of coelenterates

Despite the fact that they are multicellular, in coelenterates there are no tissues. So, they have no organs. A distinctive feature of coelenterates is the presence of specialized cells that form two layers of the body. The outer is called the ectoderm. It consists of intermediate, stinging, skin-muscular, sex and nerve cells.

The endoderm is the inner layer of the coelenterated body. This is the part of the body where the coelenterates digest food. Let's consider features of this physiological process on an example of a fresh-water hydra.

Cavity digestion

Hydra is not capable of active movement. The function of a peculiar sucker is performed by the sole, on the opposite side of which there is a mouth opening. Around it are tentacles. Where do Coelenterates digest food? This process begins in the body cavity.

Hydra affects small crustaceans and fry of fish with the help of stinging cells. Further, the tentacles move through the oral opening into the body cavity. The glandular cells that make up the endoderm produce a special secret, through which food breaks up into separate pieces.

Cellular digestion

The next structure, where coelenterates digest food, are the digestive cells. They have flagella, creating a current of water. Due to this, food particles enter the cell surface. Here the next stage of its splitting will occur.

Digestive cells also have pseudopods. These are unstable outgrowths of the cytoplasm. They grab food, and it is inside the cells. There, in the digestive vacuoles, the final cleavage process takes place. Undigested residues are also released through the oral opening.

So, we figured out where the coelenterates digest food. This process takes place in two stages. All coelenterates are predators. With the help of stinging cells they paralyze prey. Tentacles that surround the oral opening move it into the intestinal cavity. There the initial stage of digestion begins, which ends in specialized cells of the endoderm.