Guide to Shark Identification

Order Carcharhiniformes —

Ground Sharks

The ground sharks are a large family of generalized, superficially very similar sharks that include many of the most ecologically and commercially important species. All carcharhinoids share the following features:

nictitating eyelids present
mouth behind front of eyes
five pairs of gill slits
both dorsal fins without spines
anal fin present

Key to Selected Carcharhinoid Families
Sphyrnidae | Scyliorhinidae | Carcharhinidae | Triakidae

More about Ground Sharks

Family Scyliorhinidae — Cat Sharks

The catsharks are a large group of diverse but generally smallish creatures found in a wide variety of marine habitats, from rocky and coral reef to the deep-sea. All scyliorhinoids share the following characteristics:

head ‘normal’, without lateral expansions
first dorsal fin originates far posterior on body, over or behind pelvic fins

More about Cat Sharks

Swell Shark (Cephaloscyllium ventriosum)

What to Look For:

body relatively stout, capable of rapid inflation with water or air
snout very short and broadly rounded, with lobate anterior nasal flaps that partially overlap front of the mouth
first dorsal fin bluntly pointed, much larger than the second dorsal, which is angular and noticeably smaller than the anal fin
origin of first dorsal fin over pelvic bases
caudal fin relatively short, less than 20% of total length
variegated pigmentation pattern, featuring dark blotches or saddles, numerous small dark and some light spots; fins without conspicuous light margins

Size: average length about 35 inches (90 centimetres), maximum to 43 inches (110 centimetres)

Habitat: Rocky Reefs, Kelp Forests

Distribution: Tropical Eastern Pacific

Swell Shark Ecological Profile

Pyjama Catshark (Poroderma africanum)

What to Look For:

body relatively stout
snout moderately short and bluntly pointed, with finger-like anterior nasal flaps that usually do not reach front of the mouth
both dorsal fins angular, the first much larger than the second and somewhat larger than the anal fin, which is similar in length but less tall
origin of first dorsal fin behind pelvic bases
caudal fin relatively short, less than 20% of total length
unique pigmentation features striking pattern of dark, longitudinal stripes on paler background

Size: average length about 2 feet (60 centimetres), maximum about 3 feet (1 metre)

Habitat: Rocky Reefs, Kelp Forest

Distribution: Southern African, Madagascaran

Pyjama Catshark Ecological Profile

Small-Spotted Catshark (Scyliorhinus canicula)

What to Look For:

body slender, with maximum diameter over the pectoral fins
snout moderately long and smoothly rounded, with large, flap-like nasal curtain that reaches the mouth and covers shallow nasoral grooves
labial furrows on lower jaw only
both dorsal fins angular, the first much larger than the second; anal fin triangular, long and low
origin of first dorsal fin well behind pelvic bases
caudal fin relatively short, less than 25% of total length
pigmentation pattern features numerous small dark spots, usually about the diameter of the eye pupils, sometimes over obscure pattern of 8 or 9 dusky saddles; scattered white spots occasionally present

Size: average length about 2 feet (60 centimetres), maximum to about 3 feet (100 centimetres)

Habitat: Sandy Plains, Rocky Reefs

Distribution: Eastern North Atlantic/Mediterranean, West African

Family Triakidae — Smoothhound Sharks

The smoothhound sharks are active hunters specializing in crustacean prey and often associated with soft bottoms. All triakids share the following characteristics:

head ‘normal’, without lateral expansions
first dorsal fin originates in front of pelvic fins
anal fin smaller than second dorsal and with concave rear margin
precaudal pits absent
top edge of caudal fin not undulated

More about Smoothhound Sharks

Leopard Shark (Triakis semifasciata)

What to Look For:

body attenuate in young individuals, becoming increasingly solid (but never stocky) with age
snout broadly rounded with short, lobate nasal flaps not reaching front of the mouth
first dorsal fin with sloping rear margin and only slightly larger than the second
pectoral fins broadly triangular in adults
origin of first dorsal fin behind pectoral fins
caudal fin with low thrust angle, undifferentiated, flap-like lower lobe, and strong, triangular subterminal lobe
unique pigmentation pattern features bold, dark saddles — often accentuated with thick, pale outlines — and scattered large, dark spots on a lighter background; saddle marks become light-centered in adults

Size: average length about 3 to 5 feet (1 to 1.5 metres), maximum to 6 feet (1.8 metres)

Habitat: Estuaries, Sandy Plains, Rocky Reefs, Kelp Forests

Distribution: Temperate Eastern Pacific, Tropical Eastern Pacific

Leopard Shark Ecological Profile

Family Carcharhinidae —

Requiem or Whaler Sharks

The requiem or whaler sharks are solidly-built, typical sharks that are superficially very similar and thus rather difficult to identify as free-swimming animals in the wild. All carcharhinids share the following characteristics:

head ‘normal’, without lateral expansions
first dorsal fin originates in front of pelvic fins
anal fin trailing margin strongly concave
precaudal pits present
top edge of caudal fin undulated

More about Requiem or Whaler Sharks

Silvertip Shark (Carcharhinus albimarginatus)

What to Look For:

snout moderately long and broadly rounded, with small anterior nasal flaps
first dorsal fin with bluntly pointed apex, much larger than second dorsal or anal fins
first dorsal fin originates over free rear tip of pectorals
interdorsal ridge present
pectoral fins falcate and narrow-tipped
striking pigmentation pattern featuring conspicuous white tips and posterior margins on all fins except the second dorsal

Size: average length 5 to 6 feet (1.5 to 1.8 metres), maximum about 10 feet (3 metres)

Habitat: Intertidal, Sandy Plains, Rocky Reefs, Coral Reefs, Deep Sea

Distribution: Central Pacific, Tropical Eastern Pacific, Southern African, Central Indian, Madagascaran, Arabian, ?Indian, Southeast Asian, Northern Australian, Japanese

Grey Reef Shark (Carcharhinus amblyrhynchos)

What to Look For:

snout moderately long and broadly rounded, with small anterior nasal flaps
first dorsal fin with bluntly pointed apex, much larger than second dorsal or anal fins
first dorsal fin originates over free rear tip of pectorals
interdorsal ridge absent
pectoral fins falcate and narrow-tipped
pigmentation pattern features a broad, black band on posterior margin of the caudal fin; in western Pacific and Indian Oceans, first dorsal fin often white-tipped

Size: average length 3 to 4 feet (1 to 1.2 metres), maximum to at least 6 feet (1.8 metres); reputed to reach 8.4 feet (2.55 metres), but this is uncertain

Habitat: Intertidal, Sandy Plains, Coral Reefs

Distribution: Central Pacific, South Pacific, Madagascaran, Arabian, ?Indian, Southeast Asian, Western Australian, Northern Australian

Grey Reef Shark Ecological Profile

Bronze Whaler (Carcharhinus brachyurus)

What to Look For:

snout moderately long and narrowly rounded, with small anterior nasal flaps
first dorsal fin with bluntly pointed apex and short free rear tip, much larger than second dorsal or anal fins
first dorsal fin originates over or behind free rear tip of pectorals
second dorsal fin has short free tip and originates over or slightly behind the anal fin
interdorsal ridge usually absent
pectoral fins long, falcate and narrow-tipped
striking bronzy or olive grey above, white below; no conspicuous marks on any of the fins; a moderately prominent white band on each flank

Size: average length about 5 to 6 feet (1.5 to 1.8 metres), maximum to about 10 feet (3 metres)

Habitat: Intertidal, ?Estuaries, ?Sandy Plains, Rocky Reefs

Distribution: Tropical Eastern Pacific, Chilean, Argentinean, Amazonian, ?Caribbean, Eastern North Atlantic/Mediterranean, West African, Southern African, Western Australian, Southeastern Australian/New Zealand, Japanese

Silky Shark (Carcharhinus falciformis)

What to Look For:

body fairly slender
snout moderately long and narrowly rounded, with small anterior nasal flaps
first dorsal fin moderate sized and falcate, with bluntly pointed apex and long free rear tip (about half the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates behind free rear tip of pectorals
second dorsal fin low with very long free tip (over twice as long as the fin is high) and originates over or slightly behind the anal fin
interdorsal ridge present
pectoral fins long, falcate and narrow-tipped
tips of fins other than the first dorsal often dusky but not black-tipped, no conspicuous marks on any of the fins; an inconspicuous white band on each flank

Size: average length about 6.5 to 8 feet (2 to 2.4 metres), maximum to 11 feet (3.3 metres)

Habitat: Rocky Reefs, Open Ocean, Deep Sea

Distribution: Central Pacific, Tropical Eastern Pacific, Chilean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Silky Shark Ecological Profile

Galapagos Shark (Carcharhinus galapagensis)

What to Look For:

snout moderately long and broadly rounded, with small anterior nasal flaps
first dorsal fin broad, triangular, tall and erect, with a nearly straight forward margin, bluntly pointed apex and short free rear tip (about 40% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates over free rear tips of pectorals
second dorsal fin has short free tip and originates over or slightly anterior to the anal fin
interdorsal ridge present, but low
pectoral fins long, semifalcate and narrow-tipped
tips of most fins often dusky but not black-tipped, no conspicuous marks on any of the fins; an inconspicuous white band on each flank

Size: average length about 5 to 6 feet (1.5 to 1.89 metres), maximum to about 10 feet (3 metres)

Habitat: Rocky Reefs, Coral Reefs, Open Ocean

Distribution: Central Pacific, South Pacific, Tropical Eastern Pacific, South Atlantic, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Madagascaran, Southeastern Australian/New Zealand, ?Northern Australian

Bull Shark (Carcharhinus leucas)

What to Look For:

body stocky, heavy ‘nape’ in large individuals
snout very short and bluntly rounded, with small anterior nasal flaps
first dorsal fin broad, triangular to somewhat falcate, with a bluntly pointed apex and very short free rear tip (about 20% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates over or just behind axil (‘armpit’) of pectorals
second dorsal fin high with a short free tip and originates over or slightly anterior to the anal fin
interdorsal ridge absent
pectoral fins large, broad, angular and narrow-tipped
tips of fins often dusky but not black-tipped, no conspicuous marks on any of the fins; an inconspicuous white band on each flank

Size: average length 7 to 8 feet, maximum to about 11 feet (3.4 metres)

Habitat: Intertidal, Estuaries, Sandy Plains, Rocky Reefs, Coral Reefs, Fresh Waters

Distribution: Central Pacific, Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian

Bull Shark Ecological Profile

Blacktip Shark (Carcharhinus limbatus)

What to Look For:

sloping nape grading smoothly into a high back
snout moderately long and pointed, with small anterior nasal flaps
first dorsal fin large, falcate and erect, with a pointed apex and short free rear tip (about 40% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates over or slightly anterior to axil (‘armpit’) of pectorals
second dorsal fin large and high, with a short free tip and originates over or slightly anterior to the anal fin
interdorsal ridge absent
pectoral fins long, semifalcate and narrow-tipped
tips of first and second dorsal fins, pectoral fins, upper and lower lobes of caudal fin distinctly black-tipped; pelvic fins sometimes black tipped but anal fin usually completely white, including tip; a conspicuous white band on each flank

Size: average length about 5 feet (1.5 metres), maximum to 8.4 feet (2.6 metres)

Habitat: Estuaries, Sandy Plains, Rocky Reefs, Coral Reefs, Open Ocean

Distribution: Central Pacific, Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, ?Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Oceanic Whitetip Shark (Carcharhinus longimanus)

What to Look For:

body rather stocky
snout short (about equal to mouth width) and broadly rounded, with small anterior nasal flaps
first dorsal fin large, tall, erect, with a broadly rounded apex and moderately long free rear tip (about 50% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates slightly anterior to free rear tips of pectorals
second dorsal fin large and high with a short free rear tip and originates over or slightly anterior to the anal fin
interdorsal ridge usually present, but low
pectoral fins long, paddle-like and broad-tipped
tips of pectorals, first dorsal, pelvics, upper and lower caudal with white mottling; young with black blotches on tips of pelvics, second dorsal fin, anal fin, and lower lobe of caudal fin often with black saddles at origin of second dorsal and upper lobe of caudal fin as well as between the dorsal fins; an inconspicuous white band on each flank

Size: average length 5 to 8 feet (1.5 to 2.5 metres), maximum to 11.5 feet (3.5 metres) — although some exceptional females are reported to grow even larger

Habitat: Rocky Reefs, Coral Reefs, Open Ocean

Distribution: Central Pacific, Tropical Eastern Pacific, Chilean, North Atlantic, South Atlantic, Argentinean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Central Indian, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Oceanic Whitetip Shark Ecological Profile

Blacktip Reef Shark (Carcharhinus melanopterus)

What to Look For:

snout short and bluntly rounded, with moderately elongated, nipple-shaped nasal flaps
eyes oval, with long axis horizontal
first dorsal fin broad, falcate, and obviously larger than second dorsal or anal fins
first dorsal fin originates over free rear tips of pectorals
second dorsal fin large with a short free tip and originates over the anal fin origin
interdorsal ridge absent
pectoral fins long, semifalcate and narrow-tipped
tips of first dorsal and ventral caudal lobe very conspicuously black-tipped, accentuated by a pale band between the black fin tips and the brownish base color; all other fins with less prominent black tips; a conspicuous white band on each flank

Size: average length is 3 to 4 feet (1 to 1.2 metres), maximum reported to 6 feet (1.8 metres), but most adults less than 5.25 feet (1.6 metres)

Habitat: Intertidal, Estuaries, Sandy Plains, Rocky Reefs, Coral Reefs

Distribution: Central Pacific, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Caribbean Reef Shark (Carcharhinus perezi)

What to Look For:

snout moderately short and broadly rounded, with small anterior nasal flaps

first dorsal fin broad and falcate, with bluntly pointed apex and moderately long free rear tip (about a third the length of the base), and much larger than second dorsal or anal fins

first dorsal fin originates over free rear tips of pectorals
second dorsal fin has short free tip and originates over or slightly anterior to origin of the anal fin
interdorsal ridge present, but low
pectoral fins long, semifalcate and narrow-tipped
tips of underside of most fins often dusky but not black-tipped, no conspicuous marks on any of the fins; an inconspicuous white band on each flank; juveniles have a black blotch on apex of the second dorsal fin

Size: average length 5 to 6 feet (1.5 to 1.8 metres), maximum about 10 feet (3 metres)

Habitat: Sandy Plains, Coral Reefs

Distribution: Amazonian, Caribbean, Western North Atlantic

Caribbean Reef Shark Species Profile

Sandbar Shark (Carcharhinus plumbeus)

What to Look For:

snout moderately short and broadly rounded, with small anterior nasal flaps
first dorsal fin very large broad, semifalcate, tall and erect, with a bluntly pointed apex and moderately long free rear tip (about 40% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates over or slightly anterior to axil (‘armpit’ of pectorals)
second dorsal fin moderately high (2 to 3.5% of total length) has short free tip and originates over or slightly anterior to the anal fin
interdorsal ridge present, but narrow
pectoral fins long, semifalcate and narrow-tipped
tips and posterior margins of most fins often dusky but not black-tipped, no conspicuous marks on any of the fins; an inconspicuous white band on each flank

Size: average length about 6.5 feet (2 m), maximum 8 feet (2.4 metres).

Habitat: Intertidal, Estuaries, Sandy Plains, Rocky Reefs, Coral Reefs, Deep Sea

Distribution: Central Pacific, Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, ?Indian, Southeast Asian, Western Australian, Northern Australian, Japanese

Tiger Shark (Galeocerdo cuvier)

What to Look For:

snout very short (much less than mouth width) and bluntly squared-off, with short, broadly triangular nasal flaps
mouth large with long upper labial furrows, each extending from the jaw corner forward to level of the eye
slit-like spiracle behind eye
first dorsal fin broad and falcate, tall and erect, with a bluntly pointed apex and long free rear tip (about 50% the length of the base), and much larger than second dorsal or anal fins
first dorsal fin originates over free rear tips of pectorals
second dorsal fin has long free tip and originates over or slightly anterior to the anal fin
interdorsal ridge present and very prominent
pectoral fins moderately broad, semifalcate and narrow-tipped
low dermal ridge on either side of tail stalk
upper lobe of caudal fin very long and sharply pointed
unique pigmentation pattern features dark spots and vertical bars on back and flanks; markings very bold in young but fading out in adults; a race from the southern Caribbean is reportedly shiny black above, pure white below

Size: average length 11 to 14 feet (3.4 to 4.3 metres), maximum to at least 18 feet — although one gigantic female caught off Indo-China was reportedly 24 feet (7.4 metres) long

Habitat: Intertidal, Estuaries, Sandy Plains, Coral Reefs, Open Ocean, Deep Sea, Polar Seas

Distribution: Arctic, Central Pacific, ?South Pacific, Tropical Eastern Pacific, Chilean, Argentinean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Tiger Shark Ecological Profile

Sharptooth Lemon Shark (Negaprion acutidens)

What to Look For:

snout short and broadly angular (almost wedge-shaped), with small anterior nasal flaps
first dorsal fin broad, falcate, tall and erect, with a bluntly pointed apex, a short free rear tip (about 30% the length of the base), and about the same size as the second dorsal
first dorsal fin originates behind free rear tips of pectorals
second dorsal fin has short free tip and originates over or slightly anterior to the anal fin
pectoral fins long, broad, falcate and narrow-tipped
pelvic fins broad, strongly falcate and narrow-tipped
upper surfaces pale yellow-brown
range restricted to Indian, central and western Pacific oceans

Size: average length about 8 feet (2.4 metres), maximum 10.2 feet (3.1 metres)

Habitat: Intertidal, Estuaries, Sandy Plains, Coral Reefs, Open Ocean (1 record)

Distribution: Central Pacific, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Southeastern Australian/New Zealand, Northern Australian

Lemon Shark (Negaprion brevirostris)

What to Look For:

snout short and broadly rounded, with small anterior nasal flaps
first dorsal fin short, broad and non-falcate, with a bluntly pointed apex, a short free rear tip (about 30% the length of the base), and about the same size as the second dorsal
first dorsal fin originates over free rear tips of pectorals
second dorsal fin has short free tip and originates slightly anterior to the anal fin
pectoral fins long, broad, semifalcate and narrow-tipped
pelvic fins broad, non-falcate and blunt-tipped
upper surfaces pale yellow-brown
range restricted to eastern Pacific, western and eastern Atlantic

Size: average length 8 to 10 feet (2.4 to 3 metres), maximum 11 feet (3.4 metres)

Habitat: Intertidal, Estuaries, Sandy Plains, Coral Reefs

Distribution: Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic, West African

Lemon Shark Ecological Profile

Blue Shark (Prionace glauca)

What to Look For:

body slender
snout long and bluntly pointed (shaped like a narrow parabola from above or below), with small, broadly triangular anterior nasal flaps
eye large, ringed with white
first dorsal fin short, broad and non-falcate, with a bluntly pointed apex, a short free rear tip (about 30% the length of the base), much larger than second dorsal and anal fins
first dorsal fin originates well behind free rear tips of pectorals
second dorsal fin has short free tip and originates slightly posterior to the anal fin
pectoral fins long, narrow, semi-falcate and narrow-tipped
low dermal ridge on either side of tail stalk
upper surfaces dark blue, flanks brilliant ultramarine; undersurfaces pure white

Size: average length about 6 to 8 feet (1.8 to 2.4 metres), maximum to at least 13 feet (4 metres), although individuals reported as long as 21 feet (6.5 metres)

Habitat: Rocky Reefs, Kelp Forests, Open Ocean, Deep Sea, Polar Seas

Distribution: Arctic, Antarctic, North Pacific, Central Pacific, South Pacific, Temperate Eastern Pacific, Tropical Eastern Pacific, Chilean, North Atlantic, South Atlantic, Argentinean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Central Indian, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Blue Shark Ecological Profile

Whitetip Reef Shark (Triaenodon obesus)

What to Look For:

body slender
snout short and blunt, almost wedge-shaped, with unique tube-shaped anterior nasal flaps
first dorsal fin tall, broad and semi-falcate, with a bluntly pointed apex, a long free rear tip (about 50% the length of the base), and distinctly larger than the large second dorsal
first dorsal fin originates well behind free rear tips of pectorals
second dorsal fin has short free tip and originates roughly over the anal fin
pectoral fins long, broad, triangular and narrow-tipped
upper surfaces pale yellow-brown
range restricted to eastern Pacific, western and eastern Atlantic

Size: average length 4 to 5 feet (1.2 to 1.5 metres), maximum to 5.6 feet (1.7 metres)

Habitat: Sandy Plains, Rocky Reefs, Coral Reefs, Deep Sea

Distribution: Central Pacific, Tropical Eastern Pacific, Caribbean (one record), Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Northern Australian, Japanese

Whitetip Reef Shark Ecological Profile

Family Sphyrnidae — Hammerhead Sharks

The hammerheads are highly distinctive sharks found mostly in tropical waters, although the Smooth Hammerhead (Sphyrna zygaena) regularly inhabits cool waters at moderately high latitudes. As a group, the sphyrnids share one obvious characteristic:

head with lateral, canard-like extensions

More about Hammerhead Sharks

Scalloped Hammerhead (Sphyrna lewini)

What to Look For:

hammer narrow and broadly arched with prominent indentations at each nare (near the outer tip of each lobe) and the midline
first dorsal fin tall, erect, broad and semifalcate with a bluntly pointed apex
first dorsal fin origin over or slightly behind pectoral axil (‘armpit’)
second dorsal fin low with long trailing margin, about twice as long as the fin is high
pectoral fins moderately small, triangular and slightly emarginate
pelvic fins triangular and non-falcate
dusky or black tips on undersurface of pectoral fins; second dorsal fin often black-tipped

Size: average length about 7 feet (2.1 metres); maximum to at least 11.5 feet (3.5 metres)

Habitat: Estuaries, Sandy Plains, Rocky Reefs, Open Ocean, Deep Sea

Distribution: Central Pacific, South Pacific, Tropical Eastern Pacific, ?Chilean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Scalloped Hammerhead Ecological Profile

Great Hammerhead (Sphyrna mokarran)

What to Look For:

hammer narrow with an almost-straight forward margin and shallow indentations at each nare (near the outer tip of each lobe) and the midline
first dorsal fin very tall, erect, broad and falcate with a sharply pointed apex
first dorsal fin origin over or slightly behind pectoral axil (‘armpit’)
second dorsal fin low with moderately short trailing margin, about as long as the fin is high
pectoral fins moderately small, triangular and slightly emarginate
pelvic fins strongly falcate
no conspicuous fin markings

Size: average length 10 to 12 feet (3 to 3.6 metres), maximum at least 18 feet (5.5 metres), but said to reach lengths of 20 feet (6.1 metres)

Habitat: Intertidal, Sandy Plains, Coral Reefs

Distribution: South Pacific, Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Arabian, Indian, Southeast Asian, Western Australian, Southeastern Australian/New Zealand, Northern Australian, Japanese

Great Hammerhead Ecological Profile

Bonnethead Shark (Sphyrna tiburo)

What to Look For:

hammer broad with a strongly bowed (Atlantic subspecies) to angular (Pacific subspecies) forward margin and without indentations along the forward margin
first dorsal fin tall, erect, broad and semi-falcate with a bluntly pointed apex
first dorsal fin origin well behind pectoral axil (‘armpit’)
second dorsal fin low with moderately short trailing margin, about as long as the fin is high
pectoral fins moderately large and triangular
pelvic fins triangular, non-falcate
no conspicuous fin markings

Size: average length is 27 to 39 inches (70 to 100 centimetres), maximum to about 5 feet (1.5 metres)

Habitat: Intertidal, Estuaries, Sandy Plains, Coral Reefs

Distribution: Tropical Eastern Pacific, Amazonian, Caribbean, Western North Atlantic

Bonnethead Shark Ecological Profile