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).
4 stages of ALS disease. When the upper motor neurons face a serious problem such as degeneration, this causes spastic, also known as muscle contraction or tightening. Whereas, the effects on the lower motor neurons cause loss in the ability to move, muscle shrinkage, twitching, and weakness in the muscles as well.