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).
TYPES OF SHARKS. To wrap it up, let's look at some of the types of sharks we've been discussing. ANGEL SHARK: 1  flat body like a stingray -- you can tell the shark is not a ray because the pectoral fins are not attached to the head.2  They bury themselves in the sand or mud with only the eyes and part of the top of the body exposed.NGEL SHARK: 1  flat body like a stingray -- you can tell the shark is not a ray because the pectoral fins are not attached to the head. 2  They bury themselves in the sand or mud with only the eyes and part of the top of the body exposed.