Comparative characteristics of freshwater hydra andWhite Planaria gives a clear idea about the features of the organization and development of two types of multicellular animals - intestinal cavities and flatworms. In our article we will consider this question in terms of the complexity of the features of their structure.
On this issue, the comparative characteristicfreshwater hydra and white planaria are similar. The first animal got its name by habitat. Although its many related species live in the seas. Planaria also prefers small freshwater reservoirs, where it hides under driftwood and pebbles.
The type of freshwater hydra is a single polyp.It is attached to underwater objects with the base of its stalk - the sole, which acts as a sucker. At the opposite end of the body of the hydra are the tentacles. With their help, the animal captures, holds the prey and sends it to the mouth opening. Due to the presence of specialized skin and muscle cells, the hydra can shrink and bend. Unlike a freshwater polyp, planaria leads a mobile lifestyle.
Many representatives of the intestinal and flatworms lead a completely different way of life. For example, the liver flukes and tapeworm are broad, which are parasitic worms, attached to the ducts of the internal organs of the hosts.
Comparative characteristics of freshwater hydra andWhite Planaria is not possible without considering the type of food. In this matter, these organisms have much in common. Planaria and hydra are heterotrophic organisms. And both of these species are predators. Hydra hunts with stinging cells that paralyze prey.
Planaria also attacks small aquatic animals.Epithelial cells, which swell in water, help her capture and fix the victim. Organs of the digestive system planaria are the mouth and intestines. The latter has front and middle sections that end blindly.
Hydra has ray symmetry.Her body is formed by two layers - ecto-and endoderma. They include various types of specialized cells: digestive, sex, epithelial-muscular, stinging, glandular, digestive, nervous. They are scattered around the body of the polyp and do not form tissues.
White Planaria, which is representativetype flat worms, has a characteristic body shape. It is flattened in the dorso-ventral direction and resembles a small leaf. This is an animal with two-sided symmetry. In planaria appear real tissues, organs and their systems. It is a musculoskeletal, digestive, excretory, nervous, sexual. A common feature of these animals is a high level of regeneration. So, the hydra can recover from a mushy state, and the planaria is capable of vegetative reproduction.
Comparative characteristics of freshwater hydra andWhite Planaria indicates a significant increase in the level of organization of flatworms. The intestinal cavities, along with the sponges, are the first multicellular presenters of the animal world. However, they lack real tissue. This structure appears only in flatworms. Therefore, their structure and livelihoods is characterized by a higher level. The primitive features of their structure are the absence of the organs of the respiratory and circulatory systems. Therefore, gas exchange in flatworms occurs through the surface of the body.
