Hobbies And Interests
Color
The spinner shark is distinguishable from the blacktip shark by the spinner's black-tipped anal fin. Despite its name, many blacktip sharks do not feature a black tip on the anal fin. However, the dorsal fin of both species generally features an easily-recognizable black tip. Both species feature a gray skin tone and white underbelly, though spinner sharks tend to have a bronze tint as well.
Other Physical Attributes
Spinner sharks and blacktip sharks are roughly the same size, reaching an average length of 6.4 feet and weight of 123 pounds. The teeth of the spinner shark are differentiated from the blacktip's by their narrow triangular shape and oblique alignment. In contrast, the blacktip features teeth with a broader shape and more defined forward angle. Another difference is the location of the dorsal fin. The dorsal fin of the spinner shark is closer to the anterior of the body, while the blacktip dorsal fin is farther back on the shark's midsection.
Distribution
In North America, spinner sharks are found in the northern Gulf of Mexico as well as off the eastern coast of the United States, inhabiting the coastal area from northern Mexico to North Carolina. Blacktip sharks share these locations, except they can be found as far north as Massachusetts. Blacktips are also found on the western coasts of the Americas, spanning from the Gulf of California to the coast of Peru. Other locations where both species are found include the Mediterranean Sea and Indian Ocean, as well as the coasts of Africa, China and Australia.
Life Cycle
Spinner sharks are more procreative than blacktip sharks. A typical adult female spinner gives birth to between three to 20 pups a year, while the blacktip only averages one to 10 pups. In both species, male sharks reach full maturity at four to five years of age, while female sharks require seven to eight years. Spinner sharks have a slightly longer lifespan than blacktip sharks, averaging 15 to 20 years compared to the blacktip's average lifespan of 12 years.