Epidemiologists study outbreaks of diseases, the causes, locations, and how various communities are affected, utilizing relative information to aid in the prevention of future outbreaks. Epidemiologists help to keep the public informed of methods to maintain and improve public health.
Based on these criteria, the smallest known extant shark species appears to be Etmopterus perryi, males of which mature at 16 to 17.5 cm TL and gravid females have been found at 19 to 20 cm TL (Springer & Burgess 1985).
Size: The spined pygmy shark, a deep-sea shark, is one of the smallest at only about 7-8 inches, while the whale shark is the largest shark, and fish, at about 50 feet in length. Lifespan: Although lifespan varies by shark species, most sharks are long-lived and generally tend to live for 20-30 years.