A relatively small and wary shark, the blacktip reef shark rarely poses any real threat to humans. They are one of the most common species that come in contact with humans in the Indo-Pacific, along with grey and whitetip reef sharks. Blacktip sharks, although possessing an almost identical name are a separate species of requiem shark, Carcharhinus limbatus. It can be difficult to tell the species apart, but the blacktip reef shark is slightly longer and sleeker and has much more pronounced splashes of black on their fins.
Blacktip Reef Shark
Scientific & Common Names
Kingdom - Animalia
Phylum - Chordata
Class - Chondrichthyes
Subclass - Elasmobranchii
Order - Carcharhiniformes
Family - Carcharhinidae
Genus - Carcharhinus
Species - C. melanopterus
Common Names - Blacktip Reef Shark, Black Finned Shark, Reef Shark (less accurate), Blacktip Shark (also used to describe Carcharhinus limbatus)
At an adult size of about five feet, blacktip reef sharks are medium sized requiem sharks, a family that includes tiger, lemon, and bull sharks. They display what is known as countershading in that they have a white ventral (belly) area and the dorsal (back) side is a light brownish grey shade. This coloring helps them camouflage as they hunt or hide from potential predators. As their name suggests, all of their fins are tipped with black and accentuated with a lighter color.
There are three different methods that sharks use to reproduce, depending on the species. Blacktip reef sharks are viviparous, which means they give live birth after the embryos develop in the mother's uterus. Other species lay eggs, called oviparity, or they retain the eggs inside until they hatch, called ovoviviparity. Reproductive cycles and gestation are both still being studied. Different report show gestation lasting anywhere from 8-16 months and reproductive cycles occurring annually or every two years. Litters contain 2-4 young, who immediately fend for themselves upon birth.
Blacktip reef sharks prefer shallower, warmer waters and can occasionally be found in brackish or fresh waters, usually associated with mangrove swamps. The young stay close to shore, often in large groups while the adults stay closer to reefs and sandy flats. Unlike many other requiem sharks, blacktip reef sharks will often stay within a small area for an extended period of time as they hunt for small fish and octopus. These sharks pose little threat to humans and the International Shark Attack File (ISAF) has no deaths on file from them and only 11 unprovoked attacks on humans since 1959.
Sharks have a long fossil history dating from 450 million years ago, predating dinosaurs. Today, there are nearly five hundred recognized species of shark with more still to be discovered
Blacktip reef sharks are still widespread and their numbers are higher than many other shark species. However, due to overfishing and the slow reproductive tendencies of this species, they are considered to be near threatened.
Florida Museum of Natural History International Shark Attack File
Encyclopedia of Fishes - Consultant Editors: Dr. John R. Paxton & Dr. William N. Eschmeyer
Sharks in Danger: Global Shark Conservation Status with Reference to Management Plans and Legislation (v. 1) by Rachel Cunningham-Day
Sharks of the World (Princeton Field Guides) by Leonard Compagno, Marc Dando, Sarah Fowler
The Shark Handbook: The Essential Guide for Understanding the Sharks of the World by Dr. Greg Skomal