The most lethal fish to humans is the stonefish, a type of scorpionfish. This fish has 13 dorsal spines and each spine has two venom glands. The stonefish lives and hides within the muddy sand and sometimes comes in contact with an unsuspecting foot or other body part. Besides the stonefish, other scorpionfishes and some puffers are examples of poisonous fishes. Stingray, notice the tail spine Electric Organs Electric rays have large paired electric organs that are located on either side of the head, behind the eyes.
Most rays live on the ocean floor and are bottom feeders.
These rays use their electric organs for several different functions. The electric rays lie hidden beneath the sand. The voltage given off by the ray can also be used as a protective mechanism and to stun over-active prey. The small voltages given off by the rays can help them find their way in the environment by allowing them to avoid obstacles. The voltages can also act as an under water sonar.