Sphenopidae
The Sphenopidae, also known as the spearhead sharks, are a family of sharks within the order Squaliformes, which consists of the dogfish sharks, bullhead sharks, and sleeper sharks. This family contains only four species, all of which are endemic to the Southern Hemisphere. All species of Sphenopidae have elongated bodies, narrow snouts with pointed heads, and distinct, large dorsal fins positioned far back on the body. Their color ranges from grey to brown, often with darker spots or stripes. They are bottom-dwelling, carnivorous sharks that inhabit deep waters, typically found between 200 and 1000 meters (660 to 3,300 feet) below the surface.
Common Names
Sphenopidae are commonly referred to as spearhead sharks due to their distinctive, spear-shaped snout. They may also be known as longnose sharks due to the length of their snout.
Characteristics
Sphenopidae share several distinct characteristics that set them apart from other shark families. These include:
- Elongated body: They have a slender, elongated body shape, which is typical of deep-water sharks.
- Narrow snout: The snout is long and pointed, giving them their distinctive spearhead appearance.
- Large dorsal fins: The two dorsal fins are large and positioned far back on the body.
- Small eyes: Their eyes are relatively small, a common adaptation for deep-water organisms where light is scarce.
- Teeth: They have small, sharp teeth designed for catching and holding prey.
Environment
Sphenopidae are found exclusively in the Southern Hemisphere, inhabiting deep, cold waters on the continental shelves and slopes. They prefer depths ranging from 200 to 1000 meters (660 to 3,300 feet). This deep-water environment is characterized by low light levels, high pressure, and limited food availability.
References
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