Blacktip sharks inhabit muddy bays, inland lagoons and coral reef ecosystems in tropical and subtropical waters around the world. In the United states, their range extends along the eastern coastline, from New England to the Florida Keys and the Gulf of Mexico (Castro 1996). Blacktip sharks are also common throughout the Caribbean region.
These sharks have a spindle shaped body with a pointed snout, small eyes and elongated gill slits. The top part of their body ranges in color from brown to grey and their underside has a pale white coloration. These sharks do not have a pronounced ridge that runs between their two dorsal fins and are distinguished from other shark species by having dark markings on the edges of their dorsal, pectoral, pelvic and caudal fins.
Although blacktip sharks can attain lengths up to 9.2 feet, their average length is 4.9 feet. Black tip sharks are social animals that are found in groups of varying sizes. Groups are not differentiated by sex or age, however, non reproductive females and adult males do not school with pregnant females or juveniles.
These timid sharks rarely ever display aggressive behaviors towards humans and have been known to interact with divers (Compagno 1984). One interesting fact about these animals is that they leap out of the water to remove parasites from their skin and to ambush their prey (Ebert 2003;Riner and Brijnnschweiler 2003 ).
Blacktip sharks feed primarily on various species of fish including sardines, herring, anchovies, ladyfish, sea catfish, cornetfish, flatfish, threadfins, mullet, mackerel, jacks, groupers, snook, porgies, mojarra, emperors, grunts, butterfish, tilapia, triggerfish, boxfish and porcupine fish! Although 90% of their diet comes from these various fish species, blacktip sharks occasionally consume rays, skates, smaller shark species, crustaceans and cephalopods (Compagno 1984).
Mating occurs during the spring and early summer and females gestate for approximately 10-12 months (Compagno 1984). Blacktip sharks are viviparous animals that give birth to four to seven pups each year in shallow nursery grounds(Compagno 1984). Due to predation and starvation, pup mortality is extremely high during the first 15 months of life, ranging from 61-91% (Heupel and Simpfendorfer 2002).
Age of sexual maturity ranges from 4-5 years in males and 7-8 years in females. Since these sharks have low reproductive rates and are threatened by overfishing, they have been listed as near threatened by the International Union for Conservation of Nature (IUCN) (Burgess and Branstetter 2009).