Defining Features[edit | edit source]

These can include six or seven gills, a present anal fin, teardrop shaped eyes, a single dorsal fin located far posterior on the body, and a caudal fin slightly elevated above the body with a weakly developed lower lobe.

Habitat and Range[edit | edit source]

Hexanchiformes are most commonly deep sea sharks, found in depths around 300-6,000ft. They can be found globally. However, they prefer the cold, deep waters as to the Atlantic, Indian, and Pacific oceans. That being said, the Broadnosed sevengilled shark is the exception as it prefers shallower water. This shark is also known to attack humans, while other Hexanchiformes are known to not attack unless provoked.

Fisheries Conservation and Concern[edit | edit source]

Closest Relatives[edit | edit source]

Example Species in Chimaeriformes[edit | edit source]

Example Species 1[edit | edit source]

Bluntnose sixgill shark

Hexanchus griseus[edit | edit source]

Defining Features: The bluntnose sixgill shark is generally a large, deepwater shark. It has large eyes, a broad, flat head, and a small dorsal fin far along its back. After maturity, it will typically reach about 15 to 16 feet in length. It feeds nocturnally, and is not known to be a threat to humans unless provoked.

Range & Habitat: The shark is primarily a deepwater species resting on the bottom during the day up to depths of 6,500 feet. At night, the shark moves closer to the surface to feed. Little is known about the migration and behavior of these sharks due to the depths they spend most of their time at, but the species is often observed as a solitary shark.

IUCN Concern: Near threatened (globally)

Example Species 2[edit | edit source]

Frilled shark

Chlamydoselachus anguineus[edit | edit source]

Defining Features: The frilled shark is a deepwater eel-like shark. They are dark brown and have six pairs of "frilly" gills. They are dark brown in color and have broad, flattened heads. They have a small dorsal fin set far on their back.

Range & Habitat: Frilled sharks have a worldwide distribution. They are typically found near the sea floor in depths between 120-1,280m but can even be found at the surface.

IUCN Concern: Least concern (globally)

Example Species in the Gulf of Maine[edit | edit source]

Gulf Example Species[edit | edit source]

Gulf Scientific Name[edit | edit source]

Defining Features:

Range & Habitat:

IUCN Concern:

References[edit | edit source]

http://www.elasmo-research.org/education/ecology/id-hexanchiformes.htm https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/hexanchus-griseus/ https://www.iucnredlist.org/species/10030/3155348 https://marinebio.org/species/frilled-sharks/chlamydoselachus-anguineus/ https://www.iucnredlist.org/species/41794/68617785https://www.sharksinfo.com/hexanchiformes.html https://www.pbs.org/wgbh/nova/sharks/world/hexanchiformes.html#:~:text=Habitat%3A%20The%20two%20sixgills%20and,of%20temperate%20and%20tropical%20seas.

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