There's where we meet our next shark in the spotlight: the Caribbean reef shark (Carcharhinus perezi).
This species is part of the requiem shark family Carcharhinidae. Most of the sharks in this family are robust and streamlined gray. It's hard to tell this species apart from other members in this family, such as the dusky shark (C. obscurus) and silky shark (C. falciformis). However, it isn't entirely impossible to tell them apart. They have darker tipped fins and a free rear second dorsal fin. They are probably one of the largest sharks you would encounter on a reef, getting up to 3 m (10 ft) long, but usually around 2-2.5 m (6.5-8 ft) long. They scour the reef at night for prey such as fish and cephalopods. Young are known to even feast on shrimp!
They have been observed resting on the bottom of the sea or inside caves, if only for a minute or two. However, this is odd as most active sharks do not exhibit this behavior.
In the 1970's, Eugenie Clark researched the "sleeping sharks" inside the caves at Isla Mujeres off the Yucatan Peninsula. These Caribbean reef sharks were not sleeping at all, as their eyes would follow divers! It was found that this area had low salinity and high oxygen. Dr. Clark hypothesized that the freshwater inside the caves might be loosening parasites on the sharks and produce a sort of "narcotic" effect.
This species of requiuem shark is found in the tropical part of the western Atlantic, and the most commonly encountered shark in the Caribbean (probably hence the name... it stayed for the pretty ladies and sun).
These sharks are caught for their meat (to eat but also to use as leather), fins, liver oil and to use as fishmeal. However, thankfully, they have become more valuable as an ecotourist attraction. This species only has a small number of encounters with humans.
The IUCN has assessed the Caribbean reef shark as Near Threatened due to populations off of Belize and Cuba from declining from overfishing and exploitation. They are also threatened by the habitat degradation/destruction to their coral reefs.