Hammerhead Shark Trivia
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43 free Hammerhead Shark trivia questions with answers — nature quiz, new questions added Aug 2026.
This hammerhead shark trivia quiz covers the strangest head in the sea: what the cephalofoil is for (360-degree vision, depth perception and a wider spread of electroreceptors), which of the ten species has the biggest hammer, how a great hammerhead pins a stingray with its head and swallows the barbs, why great hammerheads swim on their sides, and how the little bonnethead eats seagrass and reproduces without a male. It also covers the sharks and people: 17 unprovoked bites and zero deaths, the fin trade that puts 375,000 great hammerheads a year through Hong Kong, the 2013 CITES listing, the scalloped hammerhead as the first shark under the US Endangered Species Act, the beizam totem of the Torres Strait and the aumakua guardian sharks of Hawaii. Every question was verified against a primary reference (mainly the Wikipedia articles on the hammerhead family and its species) and carries a citation. Play it with our great white, whale shark and ocean quizzes.
30 of 43 questions with answers and explanations. Play the quiz
Q 01What is the scientific name for the hammerhead shark family?
Sphyrnidae
Sphyrnidae, from the Greek sphyrna, 'hammer', is the hammerhead family; the similar-looking Sphyraenidae are the barracudas.
Q 02What is the technical name for the hammerhead's flattened, T-shaped head?
Cephalofoil
The cephalofoil is the flattened, sideways-extended head; the eyes sit at its tips, and the mouth lies underneath near the middle.
Q 03Which hammerhead is the only species not placed in the genus Sphyrna?
The winghead
The winghead shark (Eusphyra blochii) has its own genus, Eusphyra, and proportionally the largest hammer of all, while every other hammerhead sits in Sphyrna.
Q 04How wide can the hammer of the Eusphyra species be, as a fraction of its body length?
Half
Half: the Eusphyra species' hammer can be as wide as half its total length; it grows to about 1.9 m, so the hammer can span nearly a metre.
Q 05What field of vision does the eye placement on the hammer give in the vertical plane?
360 degrees
360 degrees: with eyes at the tips of the hammer, a 2009 study found hammerheads can see above and below themselves at all times, with better binocular vision than pointy-nosed sharks.
Q 06Spreading electroreceptors across the wide head lets a hammerhead sweep for prey like what?
A larger radio antenna
Like a larger radio antenna: spreading the ampullae of Lorenzini, pores that sense the electric fields of living animals, across the wide head lets the shark sweep a bigger area for prey.
Q 07Which are the hammerheads' closest relatives?
The requiem sharks
The requiem sharks (family Carcharhinidae), which include the bull, tiger and blue sharks; molecular studies place the hammerheads as their close relatives or even within them.
Q 08Which hammerhead species has the scientific name Sphyrna zygaena?
The smooth hammerhead
The smooth hammerhead is Sphyrna zygaena; it lacks the central notch on the front of its head that the scalloped hammerhead has, and ranges into cooler temperate seas.
Q 09What is the smallest hammerhead species?
Bonnethead
The bonnethead (Sphyrna tiburo) is the smallest, topping out around 1.5 m and 11 kg; it is the hammerhead most often kept in public aquariums.
Q 10How much did the 4.4 m great hammerhead caught off Boca Grande, Florida, in 2006 weigh?
580 kg
580 kg: the Boca Grande female, landed in May 2006, measured 4.4 m and was carrying 55 pups, the largest litter recorded for the species.
Q 11How can you tell a great hammerhead's head from a scalloped hammerhead's?
Straight front edge versus a notched one
The smooth hammerhead has a rounded head with no notch at all.
Q 12What is the great hammerhead's favourite prey?
Stingrays
Stingrays are the great hammerhead's favourite prey; it sweeps its head over the sand to sense rays buried there, and venomous barbs lodged in its mouth do not seem to trouble it.
Q 13How does a great hammerhead use its head when attacking a stingray?
To knock it down and pin it to the seabed
Q 21In 2007, the smallest hammerhead became the first shark known to do what?
Reproduce asexually
Reproduce asexually: a female at Nebraska's Henry Doorly Zoo gave birth in 2001 with no male present, and a 2007 DNA study found only maternal genes, proving automictic parthenogenesis.
Q 22What surprising food makes up as much as half the stomach contents of some of the smallest hammerheads?
Seagrass
Seagrass: some of the smallest hammerheads have stomachs more than half full of seagrass, which they can partly digest, making the species the first shark shown to be omnivorous.
Q 23The smallest hammerhead is the only shark known to show sexual dimorphism in what?
The shape of its head
It knocks the ray down and pins it to the seabed with its head, then pivots to bite off each pectoral fin, crippling the ray before tearing it apart with head shakes.
Q 14How many stingray spines were found in and around the mouth of one great hammerhead caught off Florida?
96
96: one great hammerhead caught off Florida had 96 stingray spines lodged in and around its mouth, and the venomous barbs did not seem to bother it.
Q 15A 2016 study found great hammerheads spend up to 90% of their time doing what to save energy?
Swimming on their side
Swimming on their side: a 2016 study of tagged great hammerheads found 'rolled swimming' up to 90% of the time, using the tall dorsal fin as a lift surface and cutting drag by about 10%.
Q 16Unlike most sharks, where have great hammerheads been observed mating?
Near the surface
A Bahamas pair spiralled upward around each other and mated on reaching the surface.
Q 17How long is a great hammerhead's gestation?
11 months
11 months: great hammerheads breed every two years after an 11-month gestation, producing litters of 6 to 55 pups, typically 20 to 40, each 50 to 70 cm long.
Q 18What is the typical litter size for most hammerhead species?
12 to 15 pups
12 to 15 pups is the usual litter for most hammerheads; the great hammerhead is the exception with 20 to 40, and the pups, given no parental care, huddle together in warm water.
Q 19How do hammerhead embryos get nourishment in the later stages of gestation?
Through a yolk-sac placenta
The depleted yolk sac transforms into a structure like a mammalian placenta.
Q 20How does a male hammerhead typically persuade a female to mate?
By biting her violently until she agrees
Reproduction happens only once a year.
The shape of its head: adult males develop a distinct bulge along the front of the cephalofoil that females lack, the only known sexual dimorphism in shark head shape.
Q 24Which other species was later found to be omnivorous, after the smallest hammerhead?
The whale shark
The whale shark: a 2022 study of tissue samples from Ningaloo Reef showed whale sharks digest and assimilate algae from sargassum, making the biggest fish an omnivore too.
Q 25What unusual social behaviour do some hammerheads show by day?
Swimming in large schools
Scalloped hammerheads gather in schools of hundreds, then split up to hunt alone at night.
Q 26Tagged scalloped hammerheads migrate between Cocos Island and mangroves in which Costa Rican fjord?
Golfo Dulce
Golfo Dulce, a tropical fjord on Costa Rica's Pacific coast; tagged scalloped hammerheads travel between Cocos Island and its mangrove nurseries, where juveniles shelter from predators.
Q 27The scalloped hammerhead was the first shark protected under which law?
The US Endangered Species Act
The US Endangered Species Act: in 2014 NOAA listed four populations of scalloped hammerhead, making it the first shark species protected under the Act.
Q 28How does the IUCN classify the great hammerhead as of 2019?
Critically Endangered
Critically Endangered: the IUCN's 2019 assessment found steep declines driven by the fin trade, and the species' low abundance and long generation time make recovery slow.
Q 29By 2013, how many unprovoked hammerhead attacks were recorded since 1580, and how many deaths?
17, with no deaths
17, with no deaths: the International Shark Attack File had logged 17 unprovoked hammerhead attacks since 1580 and no fatalities; most species are too small to hurt a person seriously.
Q 30Which city is the world's largest shark fin trade market?
Hong Kong
Hong Kong handles roughly half of the world's shark fin trade, making it the largest market; traders prize hammerhead fins for their abundant 'fin needles' (ceratotrichia).