Carcharhiniformes

Defining Features

Defining features of the carcharhiniformes family would include a wide mouth that is located behind their eyes, five pairs of gill slits, an anal fin, two dorsal fins without spines, and a nictitating membrane. They are commonly referred to as "Ground Sharks".

Habitat and Range

As the largest order of sharks, Carcharhiniformes are able to be found all over the planet, often in tropical continental shelf regions. They can be found in most inshore habitats but can also be found offshore. Some species within this order are able to swim in fresh water, further broadening their habitat and range.

Fisheries Conservation and Concern

There is concern around many of the species in this order experiencing a decline in number. Some are exposed to habitat disturbances and destruction, while others are threatened by recreational and commercial fishing. Due to the slower reproduction process of these sharks, many species in this order are highly susceptible to exploitation.

Closest Relatives

Lamniformes

Example Species in Carcharhiniformes

Ref: https://en.wikipedia.org/wiki/Blacktip_reef_shark

Black Tip Reef Shark

Carcharhinus melanopterus

Defining Features: Black Tip Reef sharks get their name from their recognizable fins. Each of their fins stand out with black tips. These sharks also have short and rounded snouts in front.

Range & Habitat: These sharks are not migratory, they tend not to travel out of a general area. They swim around reefs, drop offs, and continental and insular shelves. Similar to how they do not travel very far, they also tend to stay in shallower, clearer water. They can be found in the Indo-Pacific and Eastern Mediterranean.

IUCN Concern: Near Threatened

Ref: https://haydensanimalfacts.com/2015/10/30/5-interesting-facts-about-scalloped-hammerheads/

Scalloped Hammerhead

Sphyrna lewini

Defining Features: Large double-hammer shaped head with iconic indentation at midline. Mouth on underside. Commonly found around 5+ feet in length.

Range & Habitat: The Scalloped Hammerhead is a coastal pelagic species; it occurs over continental and insular shelves and in nearby deeper water. It is found in warm temperate and tropical waters. It can be found down to depths over 500 m, but is most often found above 25 m. The Scalloped Hammerhead is distributed globally.

IUCN Concern: Critically Endangered

Example Species in the Gulf of Maine

Ref: http://animal-unique.blogspot.com/2011/09/smooth-hammerhead-shark.html

Smooth Hammerhead

Sphyrna zygaena

Defining Features: Very flat and smooth hammer-head. No indentation in middle of head. The Smooth Hammerhead is dark olive to brownish-gray with a white ventral side.

Range & Habitat: A highly mobile species that can be found worldwide in coastal, temperate and tropical waters. Smooth Hammerheads typically stay in shallow waters around 20 m deep but have been spotted at depths up to 200 m.

IUCN Concern: Critically Endangered

References

Florida Museum of Natural History: floridamuseum.ufl.edu

Shark Sider: sharksider.com

IUCN Redlist: iucnredlist.org

Chondrichthyan Tree of Life: sharksrays.org

National Oceanic and Atmospheric Administration: noaa.gov

Fish Base: fishbase.org