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.
List of SpongeBob SquarePants characters
The Jellyfish (vocal effects by Tom Kenny) are wild animals who reside in Jellyfish Fields, a meadow in Bikini Bottom, and have a strong affinity for music. Within the series, jellyfish behave like sentient insects, squirt jelly, buzz and swarm like bees, and can sting their enemies with electric shocks that leave painful welts.