Blacktip sharks. Credit: iStock.
Releasing a sandbar shark on a shark survey.
Shark Identification for Cooperative Shark Tagging Program (S-W)
The Cooperative Shark Tagging Program is a collaborative effort between recreational anglers, the commercial fishing industry, and NOAA Fisheries to study the life history of Atlantic sharks. Sharks S - W
Overview
Accurate species identification is critical. To help with identifications we have provided information on size, distinguishing characteristics, distribution, and habitat for sharks in our region.
Sandbar Shark
Carcharhinus plumbeus
Lateral view of a sandbar shark.
Size
To about 8 ft (2.4 m).
Distinguishing Characteristics:
- First dorsal fin large, triangular, originating over or slightly before pectoral insertion
- Pectoral fins large, broad
- Snout shorter than width of mouth
- Color brownish-gray or brown above, white below
- Interdorsal ridge
Distribution
Cape Cod, Massachusetts to Florida, including Gulf of Mexico and Caribbean Sea.
Habitat
Inshore shallow coastal waters, including bays, harbors, and estuaries; typically in waters 5-180 ft (2-55 m); also offshore, occasionally to 600-810 ft (183-247 m); bottom dwelling.
Similar Species
Blacktip shark, spinner shark, and bull shark lack interdorsal ridges. Dusky shark, most difficult to distinguish, attains larger maximum size (12 ft (3.7m)); has proportionally smaller, swept-back fins, with first dorsal fin farther back over free tips of pectoral fins. Bignose shark has longer snout, smaller first dorsal fin. Silky shark has smaller first dorsal fin, which is rounded, swept back, and set farther behind free tips of pectoral fins; second dorsal fin free tip length usually more than twice fin height.
Comparison of dusky (top) and sandbar (bottom) shark lateral views at the water surface.
Apex Predator Publications and Reports - Sandbar Shark
Management of Atlantic SharksSand Tiger
Carcharias taurus
Size
To about 10.5 ft (3.2 m).
Distinguishing Characteristics:
- First dorsal fin far back on the body, closer to pelvic fins than pectoral fins
- First and second dorsal and anal fins nearly equal in size
- Snout flattened, with long mouth extending behind eyes
- Color gray to light brown above, grayish-white below; often with brownish spots scattered on body; yellowish-brown spots on juveniles
- Teeth large, needlelike, protruding from mouth, with 1-2 small caplets
- No interdorsal ridge
Distribution
Gulf of Maine to Florida, including Gulf of Mexico, Bahamas, and Bermuda.
Habitat
Coastal; surf zone and shallow bays to outer shelves; generally bottom dwelling.
Similar Species
Lemon shark has teeth without cusps; first dorsal fin farther forward, closer to pectoral fins than pelvic fins. Nurse shark has nasal barbels; lacks distinct lower lobe of caudal fin.
Apex Predator Publications and Reports – Sand tiger shark
Scalloped Hammerhead
Sphyrna lewini
Size
To about 12 ft (3.7 m).
Distinguishing Characteristics:
- Head broadly arched and hammer-shaped, marked by prominent indentation at midline ("scalloped")
- Pelvic fins with straight rear margins
- Color deep olive to brownish-gray above, shading to white below
- No interdorsal ridge
Distribution
Massachusetts to Brazil, including the Gulf of Mexico and Caribbean Sea.
Habitat
Coastal and offshore, primarily in water >72°F (22°C); coastal bays and surface waters to at least 900 ft (274 m).
Similar Species
Bonnethead has a shovel-shaped head; grows to about 5 ft (1.5 m). Smooth hammerhead lacks central indentation on anterior margin of head. Great hammerhead attains larger maximum size (18.5 ft (5.6 m)); has very high first dorsal fin, pelvic fins with curved rear margins.
Apex Predator Publications and Reports - Scalloped hammerhead shark
Management of Scalloped hammerhead shark
Shortfin Mako
Isurus oxyrinchus
Size
To about 13 ft (4 m).
Distinguishing Characteristics:
Lateral view of a shortfin mako shark's head showing the conical pointed snout.
- Snout conical, pointed
- Caudal fin lunate with single keel on caudal peduncle
- Color deep blue above; light metallic blue sides; snow-white below, including underside of snout and area around mouth
- Teeth long, bladelike, smooth-edged, protruding from mouth
Distribution
Newfoundland, Canada, to Brazil, including the Gulf of Mexico and Caribbean Sea. Common in the U.S. Northeast.
Habitat
Offshore from surface to at least 500 ft (152 m); generally in waters >61°F (16°C).
Similar Species
Porbeagle has secondary keels on the caudal fin, teeth with lateral cusplets; prefers colder water. Longfin mako has larger eyes, longer pectoral fins, dusky or blue-black underside of snout and area around the mouth. Blue shark lacks lunate caudal fin, caudal keels, sharply pointed snout. White shark has triangular teeth with serrated edges, blunter snout.
Apex Predator Publications and Reports – Shortfin mako shark
Management of Shortfin mako shark
Silky Shark
Carcharhinus falciformis
Size
To about 11 ft (3.4 m).
Distinguishing Characteristics:
- Second dorsal fin with long free tip, usually more than twice fin height
- First dorsal fin rounded, swept back, originating behind free tips of sickle-shaped pectoral fins
- Color gray-brown or bronze above, white below
- Interdorsal ridge
Distribution
New York to southern Brazil, including the Gulf of Mexico and Caribbean Sea. Uncommon north of Delaware.
Habitat
Offshore, over deep water reefs and near continental and insular slopes, primarily surface waters; juveniles closer to shore.
Similar Species
Dusky shark has blunter snout, smaller eyes, second dorsal free tip length rarely more than twice fin height. Sandbar shark and bignose shark have higher first dorsal fins placed farther forward, closer to pectoral fins. Night shark have green eyes, longer snout, characteristic teeth. Blacktip shark and spinner shark lack interdorsal ridges.
Apex Predator Publications and Reports – Silky shark
Smooth Dogfish
Mustelus canis
Size
To about 5 ft (1.5 m).
Distinguishing Characteristics:
- Fin spines absent
- Dorsal spots absent
- First and second dorsal fins nearly equal in size; second dorsal fin much larger that anal fin
- Teeth pavement like, noncutting
- Eyes large, oval-shaped, catlike; prominent spiracle behind eyes
- Color olive-gray to brown above, yellowish- or grayish-white below
- Interdorsal ridge
Distribution
Massachusetts to Florida, including Gulf of Mexico, possibly Caribbean Sea. Uncommon north of Massachusetts.
Habitat
Coastal; bays and nearshore waters, usually <60 ft (18 m) but down to 660 ft (200 m) or deeper; primarily near or on bottom.
Similar Species
Spiny dogfish has white spots, dorsal spines; lacks anal fin. Atlantic sharpnose shark has white spots on the back and sides.
Apex Predator Publications and Reports – Smooth dogfish
Smooth Hammerhead
Sphyrna zygaena
Size
To about 13 ft (4 m).
Distinguishing Characteristics:
- Head broadly arched and hammer-shaped, lacking indentation at midline ("smooth")
- Pelvic fins with straight to slightly concave rear margins
- Color deep olive to brownish-gray above, shading to white below
- Underbody of posterior portion of body may have numerous small dark spots on lighter-shaded areas
- No interdorsal ridge
Distribution
Nova Scotia, Canada to Florida.
Habitat
Coastal and offshore; from surface to at least 66 ft (20 m); tolerates much cooler waters than most hammerheads.
Similar Species
Bonnethead shark has a shovel-shaped head; grows to about 5 ft (1.5 m). Scalloped hammerhead and great hammerhead have prominent central indentations on the anterior margin of head. Great hammerhead attains larger maximum size (18.5 ft (5.6 m)); has very high first dorsal fin, pelvic fins with curved rear margins.
Apex Predator Publications and Reports – Smooth hammerhead shark
Spinner Shark
Carcharhinus brevipinna
Lateral view of a spinner shark.
Size
To about 9 ft (2.7 m).
Distinguishing Characteristics:
- Anal, first and second dorsal, pectoral, and lower caudal fins black-tipped (look as if dipped in jet black paint) in specimens >2.6 ft (0.8 m)
- First dorsal fin fairly small, originating over or just behind free tips of pectoral fins, apex rounded
- Snout pointed, as long as or longer than width of mouth
- Color gray or bronze above with light, conspicuous wedge-shaped band or Z-shaped line on sides beginning near pectoral fins, gradually widening rearward to pelvic fins to merge with white on belly
- No interdorsal ridge
Distribution
Virginia to Florida, including the Gulf of Mexico; possibly into Caribbean.
Habitat
Coastal and offshore. Common in shallow waters <100 ft (30 m).
Similar Species
Blacktip shark, most difficult to distinguish, has all black-tipped fins except for white anal fin. Finetooth shark has unmarked fins, shorter snout, longer gills. Sandbar shark, dusky shark, night shark, and silky shark have interdorsal ridges.
Comparison of blacktip and spinner shark tail regions demonstrating the black coloration on the spinner shark anal fin and the lack of color on the blacktip shark anal fin.
Apex Predator Publications and Reports – Spinner shark
Spiny Dogfish
Squalus acanthias
Lateral view of a spiny dogfish.
Size
To about 4.5 ft (1.4 m).
Distinguishing Characteristics:
- Dorsal fins bother preceded by a single spine
- Anal fin absent
- Body with scattered small white spots
- Color slate-gray or brownish-gray above, pale gray to white below
- Interdorsal ridge weak
Distribution
Greenland to Florida and Cuba. Uncommon south of North Carolina.
Habitat
Coastal and offshore; surface waters to 3,000 ft (914 m), usually near the bottom in waters 43-52°F (6-11°C).
Similar Species
Smooth dogfish and Atlantic sharpnose shark have anal fins, lack dorsal fin spines. Smooth dogfish lacks white spots.
Apex Predator Publications and Reports – Spiny dogfish
Tiger Shark
Galeocerdo cuvier
Dorsolateral view of a tiger shark.
Size
To about 18 ft (5.5 m).
Distinguishing Characteristics:
- Dorsal surfaces of juveniles covered with dark blotches on bluish- or greenish-gray to black background; blotches fuse to form tigerlike vertical bars or stripes as shark grows; coloration fades to gray and stripes become less distinct in adults
- Snout blunt and wide, much shorter than width of mouth; long labial furrows around corners of mouth reaching eyes
- Teeth serrated with deep notch on outer margins, similar in both jaws
- Interdorsal ridge low
Distribution
Cape Cod to Uruguay, including the Gulf of Mexico and Caribbean Sea.
Habitat
Coastal waters close inshore to the outer continental shelf; offshore including oceanic island groups.
Similar Species
Characteristic teeth and markings of tiger shark distinguish this species from other Atlantic sharks.
Apex Predator Publications and Reports – Tiger shark
Whale Shark
Rhincodon typus
Lateral view of a whale shark.
Size
To about 40 ft (12.2 m).
Distinguishing Characteristics:
- Back and sides marked with unique checkerboard pattern of white-to-yellow spots and transverse bars on dark gray to reddish- or greenish-gray background
- Head broad and flat with short snout
- Mouth near tip of snout in front of eyes
- Sides with three prominent ridges
Distribution
New York to central Brazil, including the Gulf of Mexico and Caribbean Sea.
Habitat
Coastal and offshore; sometimes enters lagoons of coral atolls; most commonly 68-77°F (20-25°C).
Similar Species
Size and unique markings of whale shark distinguish this species from other Atlantic sharks.
Apex Predator Publications and Reports – Whale shark
White Shark
Carcharodon carcharias
Underwater view of a large white shark.
Size
To about 21 ft (6.4 m).
Distinguishing Characteristics:
- Teeth large, triangular, serrated (juvenile tooth pictured)
- Snout conical
- First dorsal fin large, triangular
- Color leaden-white to brown or black above, shading to gray-white below
- Caudal fin lunate with single keel on caudal peduncle
Distribution
Newfoundland, Canada, and Gulf of St. Lawrence to Florida, Cuba, Bahamas, and Gulf of Mexico. Uncommon throughout its range.
Habitat
Coastal and offshore along continental shelf and islands.
Similar Species
Basking shark attains larger maximum size (around 32 ft (9.8 m)); has gill slits nearly encircling head. Shortfin mako, longfin mako, and porbeagle have bladelike, smooth-edged teeth, different coloration; attain smaller maximum size. Porbeagle has secondary keels on caudal fin.
Other Species
- Shark Identification for Cooperative Shark Tagging Program (A-B)
- Shark Identification for Cooperative Shark Tagging Program (C-P)
More Identification Information
- Shark Identification for Cooperative Tagging Program
- Shark Identification Placard
- Prohibited Shark Identification Placard
- Shark Research in the Northeast
- Tagging Instructions and Resources for Volunteers
Blacktip sharks. Credit: iStock.
Releasing a sandbar shark on a shark survey.
