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| SCIENTIFIC
CLASSIFICATION |
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| COMMON
NAME: |
bonnethead shark |
| KINGDOM: |
Animalia |
| PHYLUM: |
Chordata |
| CLASS: |
Chondrichthyes |
| ORDER: |
Carcharhiniformes |
| FAMILY: |
Sphyrnidae |
| GENUS
SPECIES: |
Sphyrna tiburo |
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| DESCRIPTION: |
Species is a smaller member of the hammerhead family
with a unique narrow shovel-shaped head. Head is
noticeably more rounded in appearance than with
other members of Sphyrnidae. Additionally, the head
lacks indentations on its anterior edge. Its dentition
includes enlarged, molariform posterior teeth. The
posterior edge of the first dorsal occurs prior
to the anterior edge of the pelvic origins. The
upper lobe of the caudal fin is noticeably larger
than the lower lobe. |
| MALE |
External
claspers located on the far underside of the body
- forward of the caudal fin - distinguish males. |
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| SIZE: |
150 cm (4.9 ft) max |
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| WEIGHT: |
11 kg (24.3 lbs) max |
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| DIET: |
Primarily crustaceans (i.e. crabs, shrimp, isopods,
and even barnacles); also bivalves, octopi and small
fish |
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| GESTATION: |
Species is viviparous with a yolk-sac placenta.
Within Florida waters, observations suggest that
there is either a spring and autumn mating season
or that there is a year-round mating season. Within
Brazilian waters, observations suggest that the
mating season occurs in the spring. |
| LITTER
SIZE |
4-16
pups |
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| SEXUAL
MATURITY: |
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| MALE |
52-75 cm |
| FEMALE |
84 cm or less |
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| LIFE
SPAN: |
Approximately 12 years |
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| RANGE: |
Western Atlantic: Rhode Island (seasonally) and
North Carolina to the Caribbean and southern Brazil
Eastern Pacific: southern California to Ecuador |
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| HABITAT: |
This species is abundant within inshore, coastal,
continental and insular shelf areas within its range.
They are commonly found in estuaries, shallow bays
and channels, mud and sand flats, and reef habitats.
They typically occur at depths of 10-25 meters;
however, species may be found at depths of 80 meters
or better. Additionally, species is known to exploit
the shallower surf and intertidal zones. |
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| POPULATION: |
GLOBAL |
Global population is unknown, but species is abundant
through range |
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| STATUS: |
IUCN |
Not
listed |
| CITES |
Not listed |
| USFWS |
Not
included in the U.S. National Marine Fisheries Services
(NMFS) management plan of 1993 |
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| 1. |
Species
is typically observed in groups of 3-15. Rarely
observed as individuals. |
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| 2. |
A six-month behavioral study of a group of ten bonnethead
sharks in a semi-natural enclosure documented eighteen
unique postures and action patterns - with the group's
daily rhythm of activity peaking in the late afternoon.
Observations indicated a distinct dominance hierarchy,
mitigated in part by individual size and sex. |
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| 3. |
For
more information about sharks & rays, explore
the sharks
& rays info book. |
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Species is commonly taken via small-scale fisheries.
Bonnetheads are caught as by-catch in shrimp trawls,
and are either considered by-catch or a targeted
species when caught via trammel nets, bottom longlines,
or hook-and-line. When targeted as a catch species,
they are utilized fresh, frozen or dry-salted for
human consumption. Additionally, they are processed
as fishmeal. |
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| Compagno,
Leonard J.V., FAO Species Catalog, Vol. 4 Sharks
of the World. United Nations Development Programme,
Food and Agriculture Organization of the United
Nations, Rome, 1984. |
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www.fishbase.org |
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