Blackfin Shark: Blacktip Size, Bites and ID vs Spinner

Blackfin shark is another name for the blacktip shark, Carcharhinus limbatus. Wikipedia lists blackfin shark among its common names, alongside blacktip whaler and spotfin ground shark. The name comes from the black tips on the fins, which are the first thing most people notice.

It is a medium-sized requiem shark. Most adults are about 1.5 m (4.9 ft) long; the largest known was 2.8 m (9.2 ft) and 123 kg (271 lb) (Wikipedia). NOAA Fisheries gives up to 6.5 ft for the Atlantic population. Blacktips live in tropical and subtropical coastal water around the world, usually less than 30 m deep, in muddy bays, island lagoons and the drop-offs near coral reefs, and they tolerate brackish water (Wikipedia).

They are known for leaping clear of the water while feeding and spinning three or four times before falling back (Wikipedia).

The spinner shark (Carcharhinus brevipinna) is the look-alike that causes most mistakes, because it also has black fin tips and also spins out of the water. Check these marks:

• Anal fin: white on the blacktip (NOAA); black-tipped on an adult spinner (Wikipedia)
• First dorsal fin: on the spinner it is a little more triangular and set further back (Wikipedia)
• Snout: the spinner's is long and pointed (Wikipedia)
• Size: the spinner reaches 3 m (9.8 ft), a bit larger than the blacktip (Wikipedia)

A side-on photo that shows the anal fin clearly is the most useful single picture. From a boat or a pier, photograph the whole fish and then the underside if it rolls.

They bite people more often than most sharks but rarely do serious harm. The International Shark Attack File (Florida Museum) records 35 unprovoked bites by blacktip sharks from 1580 to the present, none fatal. ISAF also says it suspects blacktips account for most of the requiem shark bites in Florida, though those cases lack the evidence to be conclusive. Wikipedia puts the blacktip's share of Florida shark bites at 16%.

ISAF also notes that the species behind a bite is hard to confirm, because victims rarely get a good look at the shark. Get medical help for any shark bite.

By ISAF's count of unprovoked bites from 1580 to the present:

• White shark: 351 bites, 59 fatal (the #1 deadliest)
• Tiger shark: 142 bites, 39 fatal (#2)
• Bull shark: 119 bites, 26 fatal (#3)
• Blacktip shark: 35 bites, 0 fatal
• Spinner shark: 16 bites, 0 fatal

ISAF notes that identifying the shark in a bite is difficult, so these figures depend on reports where the species could be named.

No measured shark comes close. The shortfin mako is the fastest shark, and claims online say it keeps pace with boats at up to 70 km/h (43.5 mph). The Save Our Seas Foundation reports that the highest measured burst speed for a mako was 18 km/h (11 mph), with a cruising speed of 3.24 km/h (2 mph), and that no wild mako has been scientifically recorded at 70 km/h.

NOAA Fisheries says males mature at 4 to 5 years and females at 6 to 7, mating runs from March to June, and after an 11 to 12 month pregnancy Atlantic females have about three pups per litter (four to five in the Gulf). The US Atlantic stock (assessed 2021) and Gulf stock (assessed 2018) are not overfished.

Blacktip is sold as seafood in the US. NOAA lists 130 calories, 21 g of protein and 5 g of fat per 100 g of raw meat. Shark fishing rules are federal and state, and several look-alike sharks are protected, so be certain of the species before keeping one; if you are not, release it.

Research and drafting for this page were assisted by AI, and every figure was checked against the sources listed below on 25 September 2026. Where two sources disagree, both figures are given with their source.