Evolution of nervous systems
Jellyfish, comb jellies, and related animals have diffuse nerve nets rather than a central nervous system. In most jellyfish the nerve net is spread more or less evenly across the body; in comb jellies it is concentrated near the mouth. The nerve nets consist of sensory neurons that pick up chemical, tactile, and visual signals, motor neurons that can activate contractions of the body wall, and intermediate neurons that detect patterns of activity in the sensory neurons and send signals to groups of motor neurons as a result. In some cases groups of intermediate neurons are clustered into discrete ganglia.
Jellyfish as food
Jellyfish salad, a popular dish in some areas of Asia, may be prepared using cold marinated jellyfish that is thinly sliced. Some Asian airlines serve jellyfish salad as a part of their airline meal fare. Jellyfish sushi is consumed in Japan. In Thailand, a crunchy style of noodle is produced using jellyfish. The Japanese company Tango Jersey Dairy produces a vanilla and jellyfish ice cream. The ice cream is prepared using Nomura's jellyfish ("Echizen kurage" in Japanese), and involves soaking cubes of the diced jellyfish in milk. It has been described as "slightly chewy." Another reaction to the 2009 Japanese Nomura's jellyfish bloom, students in Obama, Fukui designed a Nomura Jellyfish powder to be used to make caramel sweets as part of a NASA-designed food safety management system established in the school.