The scalloped bonnethead (''Sphyrna corona'') is a rare, little-known species of
hammerhead shark in the
family Sphyrnidae. Its other common names include the mallethead shark and the crown shark.
It is found in
tropical and
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
waters in the eastern
Pacific Ocean, from
Mexico to
Peru, and possibly as far north as the
Gulf of California.
[Compagno, Leonard J. V. (1984) ''Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date''. Rome: Food and Agriculture Organization. .] It frequents inshore habitats over soft bottoms (mud, sand, and gravel) to a depth of 100 m, and also enters
mangroves and
estuaries.
Probably the smallest species of hammerhead shark, the scalloped bonnethead measures up to 92 cm long.
Its mallet-shaped head, called a cephalofoil, is moderately wide (24-29% of total length) and elongated lengthwise. The front margin is broadly arched, with shallow lateral and medial indentations, and no prenarial grooves. The mouth is small and strongly arched. The anal fin is long and has a nearly straight rear margin. Its coloration is gray above and white below, with no prominent fin markings. The similar
scoophead (''S. media'') can be distinguished by a shorter snout, a broader mouth, and a deeply concave anal fin margin.
Like other hammerheads, the scalloped bonnethead is
viviparous, with presumably two pups per litter. The young are born at 23 cm or above; an adolescent male has been recorded at 51 cm long, and an adult at 67 cm. It may be taken by local inshore
fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
, but data is lacking.
It feeds on or near the bottom, on
crustaceans,
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
s,
cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...
s,
echinoderms, and
bony fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...
es.
[Sphyrnidae: Sphyrna corona]
. ''Discover Life''. Retrieved on October 24, 2008.
Sphyrna corona head.jpg, Head, underside
Sphyrna corona head2.jpg, Head, top side
Sphyrna corona jaws.jpg, Jaws
References
External links
Species Description of Sphyrna corona at www.shark-references.com* http://researcharchive.calacademy.org/research/Ichthyology/Types/index.asp?xAction=Search&Family=Sphyrnidae&RecStyle=Full&PageStyle=Multiple&OrderBy=Family,%20TypeName,%20CatNum
{{Taxonbar, from=Q289691
scalloped bonnethead
Fish of the Gulf of California
Fish of Mexican Pacific coast
Western Central American coastal fauna
Fish of Colombia
Fish of Ecuador
Taxa named by Stewart Springer
scalloped bonnethead