What is the anatomy of a jellyfish?

Answer 1

Most jellyfish do not have specialized digestive, osmoregulatory, central nervous, respiratory, or circulatory systems. The manubrium is a stalk-like structure hanging down from the center of the underside, with the mouth at its tip. This opens into the gastrovascular cavity, where digestion takes place and nutrients are absorbed. It is joined to the radial canals which extend to the margin of the bell. Jellyfish do not need a respiratory system since their skin is thin enough that the body is oxygenated by diffusion. They have limited control over movement, but can use their hydrostatic skeleton to navigate through contraction-pulsations of the bell-like body; some species actively swim most of the time, while others are mostly passive. Depending on the species, the body contains between 95 and 98% water. Most of the umbrella mass is a gelatinous material - the jelly - called mesoglea which is surrounded by two layers of protective skin. The top layer is called the epidermis, and the inner layer is referred to as gastrodermis, which lines the gut.

Answer 2

A jellyfish is composed of a gelatinous umbrella-shaped body called a bell and trailing tentacles. They have a simple nerve net rather than a central nervous system and lack a brain or specialized organs for respiration or circulation. They have a mouth located on the underside of the bell for consuming food.