This shark is not to be confused with our star, the blacktip reef shark, (Carcharhinus limbatus).
If you guessed the one on the right, you are correct!
The blacktip shark, on the other hand, is a sleek grey/blue on the dorsal side and contrasting white below, a white band across their flank, with black markings on the tips of its fins (pectoral, dorsal, pelvic and caudal). THEY DO NOT HAVE BLACK MARKINGS ON THEIR PELVIC FINS. They usually get no bigger than 1.5 m (or about 5 ft).
Unlike the blacktip reef shark that has a small home range, according to genetic analyses, there is a variation in the black tip shark—a population in the western Atlantic Ocean has been confirmed isolated from the rest in the surrounding area. They’re quite cosmopolitan, seen in shallow, tropical areas as well as offshore. Be very careful in deciphering just which blacktip you are seeing.
Example: When I’ve gone diving, the C. limbatus demeanor is relaxed. While on a dive in the Bahamas with a local school, I swam stomach-to-stomach with one, to show the kids aboard the glass-bottomed boat that they were not to be afraid of these animals (obviously I left adequate enough room between the two of us and respected the shark’s space, never touching it nor riding it). I stressed the difference between the blacktip and blacktip reef shark through physical characteristics (also, the reef shark wouldn’t have let me been so close) and range.
The blacktip reef shark mating is absolutely fascinating, with scientists hypothesizing that females release chemical signals for males to follow. Once a female is tracked down, a male will… well, snout goes down there as part of courting. Gestation time for blacktip reef sharks is debated from anywhere of 7 months up to 16 months, although the latter has not been noted and is deemed unlikely. They are viviparous, usually giving birth to a litter of 2-5. Females give birth in nurseries that pups have a high site fidelity to later on in life.
No, really, they don’t.
They can asexually reproduce, unlike the blacktip reef shark. Not the most favorable way of going about things, but it gets the job done when a girl’s in a pinch.
The blacktip reef shark, although sometimes used for its meat, fins and oil, is not targeted by commercial fisheries. Recreational fisheries don’t really pay mind to these animals, either.
In my Fish Biology lab class, we were able to obtain an unnamed shark from bycatch and students were asked to name it.
Note how the anal fins do not have any black markings.
Spinner sharks have a black mark on the dorsal surface of their pectoral fins, and anal fins. Both sharks are common “Caribbean” sharks, although blacktips are usually found closer to shore.
Both blacktip and blacktip reef sharks have been assessed as Near Threatened (NC) by the International Union for Conservation of Nature (IUCN), on the basis of their low reproductive rate and possible overfishing threats.
Spinner Shark Identification Video by Mark Sampson:
Blacktip Identification Video by Mark Sampson:
This also allowed me to educate people on the blacktip shark as well as a little bit of the spinner shark.