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).
Biology of whale sharks (Rhincodon typus). Whale sharks are the largest sharks of their kind, but despite their size they are completely harmless. Their behavior is characterized by slow swimming movements in their search for food on the water's surface.