The scalloped bonnethead shark (Sphyrna corona) is also known as the mallethead shark or crown shark. These sharks are found in the East Pacific Ocean and are one of the 9 species of hammerhead sharks - species that all have unique hammer or shovel-shaped heads.
Because of the location of their eye, scalloped bonnethead sharks have near to 360-degree vision and great depth perception. Compared to some other shark species, the habits of the scalloped bonnethead shark are poorly known.
Description:
Scalloped bonnethead sharks have a gray back and white underside that extends up to the back of the head. Their head has broad blades and on the underside, a small, arched mouth.
These sharks may be the smallest species of hammerhead. The maximum length of the scalloped bonnethead shark is about 3 feet, and its average length is about 2 feet. They have a grayish-brown to light gray back, and white underside. Like other hammerheads, they have 5 gill slits.
Classification:
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Gnathostomata
- Superclass: Pisces
- Class: Elasmobranchii
- Subclass: Neoselachii
- Infraclass: Selachii
- Superorder: Galeomorphi
- Order: Carcharhiniformes
- Family: Sphyrnidae
- Genus: Sphyrna
- Species: corona
Habitat and Distribution:
Scalloped bonnethead sharks are not as widely distributed as some hammerheads. They live in tropical waters of the East Pacific Ocean from Mexico to Peru.
Feeding:
Scalloped bonnethead sharks eat crustaceans, gastropods, bivalves, cephalopods, echinoderms and fish.
Reproduction:
Shark Attacks:
Hammerhead sharks are generally not dangerous to humans, although one should be wary of larger hammerheads.
Hammerhead sharks in general are listed by the International Shark Attack File as #8 on its list of species responsible for shark attacks from the years 1580 to 2011. During this time, hammerheads were responsible for 17 non-fatal, unprovoked attacks and 20 fatal, provoked attacks.
Conservation:
The scalloped bonnethead shark is listed as near threatened on the IUCN Red List, which notes that limited data on this species is available and these sharks are likely threatened by fishing.
References and Further Information:
- Carpenter, K.E. Scalloped Bonnethead: Sphyrna corona. Accessed June 30, 2012.
- Compagno, L., Dando, M. and S. Fowler. 2005. Sharks of the World. Princeton University Press.
- Discover Life. Scalloped Bonnethead. Accessed June 30, 2012.
- Florida Museum of Natural History. 2012. ISAF Statistics on Attacking Species of Shark. Accessed June 30, 2012.
- Mycock, S.G. (SSG South America Regional Workshop, June 2003) 2004. Sphyrna corona. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1.
. Accessed June 30, 2012. - Viegas, J. 2009. Scalloped Hammerhead and Bonnethead Sharks have 360 Degree Vision. Accessed June 30, 2012.
