Negaprion

Negaprion is one of the 12 genera in the family Carcharhinidae. There are currently two known living species in this genus: the Lemon shark, and the Sicklefin lemon shark.
Both species are large and stocky, have a wide, blunt snout, and have two large dorsal fins of similar size. They are both yellowish-brown on their dorsal surface, and have a white belly.
They also both have a similar diet consisting of bony fish, crustaceans, stingrays, and smaller sharks. Also, both species are viviparous.
Lemon shark.
The Lemon shark is the smaller of the two species, reaching a maximum length of 3.4 metres, but usually ranges between the lengths of 2.4 to 3 metres long. Pups are around 24 to 26 inches long when born.
The Lemon shark inhabits tropical and subtropical shallow waters of coastal areas of the Atlantic and Pacific Ocean. It is often found in coral reefs, mangroves, enclosed bays, and even river mouths. 
Sicklefin lemon shark.
The Sicklefin lemon shark is the larger of the two species, reaching a maximum length of 3.8 metres. Pups are around 18 to 32 inches long when born.
The Sicklefin lemon shark inhabits continental and insular shelves, and is common on coral reefs, as well as in shallow, sandy-bottom lagoons, and mangrove swamps.