The great white shark is very well known for its size, with the  largest individuals known to have approached or exceeded 6 metres  (20 ft) in length and 2,268 kilograms (5,000 lb) in weight. It  reaches maturity at around 15 years of age and can have a life span  of over 30 years.
Benign fasciculation syndrome is characterized by occasional or nearly continuous twitching of various skeletal (voluntary) muscles in the body. This type of muscle twitching can also be seen in association with serious disorders like spinal injury, multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS).
Amyotrophic lateral sclerosis (ALS): A classic motor neuron disease. Motor neuron diseases are progressive chronic diseases of the nerves that come from the spinal cord responsible for supplying electrical stimulation to the muscles.This stimulation is necessary for the movement of body parts. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. The loss of these motor neurons causes the muscles under their control to weaken and waste away, leading to paralysis. The cause of this disease process is still unknown.