Jellyfish become one of the dreaded animals of many people who vacation to the beach, because the jellyfish are known to have a nasty sting. However, in fact many other facts that we can know about the jellyfish. They have some unique characteristics in their history and life cycle.
A. Jellyfish made up more than 95% water
The body of the jellyfish is very soft and smooth. They also do not have a frame structure or an outer shell. Jellyfish need water for their bodily needs, if they do not get water or are removed from water, then they will die.
B. Jellyfish is a radial symmetry
This means that they are symmetrical, from the top of their bell's body to the tip of the tentacle. They have the upper and lower sides, but do not have the left side and will. This is certainly different from other types of animals, such as mammals, reptiles, birds, and arthropods that are bilateral symmetries
C. Jellyfish has a simple digestive system, with just one hole
They take the food by mouth located at the bottom of the bell. Food is then digested in a sac structure called coelenterons or gastrovascular cavity. Waste material or food waste is passed through the mouth.
D. Move like a water jet
To move forward, the jellyfish take the water into their bell muscles and then spray it out from behind their bodies. It creates a water jet-like shape. Apart from that movement, the jellyfish also moves by floating on the water currents.
E. Jellyfish have no brain, blood, and nervous system
The senses they have are very primitive. They have eye spots that can feel the dark light and chemosensory holes that help them identify the prey.