Chordata · chordates

Dusky shark

Carcharhinus obscurus

Carcharhinidae · requiem sharksIUCN: Endangered
Dusky shark
Photo: Happy Little Nomad from Everywhere, Anywhere · CC BY-SA 2.0 · Wikimedia Commons · resized

A large, slow-maturing requiem shark of coastal and shelf waters.

Fun factFemales don't breed until about 20 years old, so the species recovers slowly from overfishing.

Waters
Worldwide, Northeast US
Depth zone
Coastal shallows & estuaries, Continental shelf, Open-ocean surface waters
Diet
Fish, rays & squid
Size
Up to 4 m

Classification

Chordata › Chondrichthyes › Carcharhiniformes › Carcharhinidae

  1. Kingdom Animalia animals
    • Many-celled organisms that eat other living things for energy (heterotrophs)
    • Cells have no cell walls
    • Most can move at some stage of life
  2. Clade Bilateria bilateral animals
    • Body has a left and right side that mirror each other (bilateral symmetry)
    • Head end with concentrated nerves; three tissue layers
    • Includes about 99% of all living animal species
  3. Clade Deuterostomia deuterostomes
    • In the embryo, the first opening becomes the anus and the mouth forms second
    • Includes echinoderms and chordates
  4. Phylum Chordata chordates
    • At some stage of life: a stiffening rod along the back (notochord)
    • A hollow nerve cord along the back (dorsal)
    • Slits in the throat (pharyngeal slits) and a tail past the anus
  5. Subphylum Vertebrata vertebrates
    • A skull (cranium) protecting a brain
    • Backbone or similar support around the nerve cord
    • Includes fishes, amphibians, reptiles, birds, and mammals
  6. Infraphylum Gnathostomata jawed vertebrates
    • Jawed vertebrates: jaws formed from gill arches
    • Paired fins or limbs
    • Includes all fishes except hagfish and lampreys, plus all tetrapods
  7. Class Chondrichthyes cartilaginous fishes
    • Skeleton made of cartilage, not bone
    • Skin covered in tooth-like scales (denticles)
    • Teeth constantly replaced; males have claspers for mating
  8. Subclass Elasmobranchii sharks & rays
    • Sharks and rays: five to seven separate gill slits on each side
    • Many rows of replaceable teeth
  9. Clade Selachii sharks
    • Sharks: gill slits on the sides of the head
    • Pectoral fins not joined to the head
  10. Superorder Galeomorphii galeomorph sharks
    • Sharks with an anal fin and five gill slits
    • Includes most familiar sharks
  11. Order Carcharhiniformes ground sharks
    • Ground sharks: lower eyelid (nictitating membrane) that closes over the eye
    • Anal fin and two dorsal fins
    • The largest shark order
  12. Family Carcharhinidae requiem sharks
    • Requiem sharks: streamlined bodies; many give live birth via a placenta
  13. Genus Carcharhinus
    • Species in the same genus are very close relatives and often look alike.
  14. Species Carcharhinus obscurus Dusky shark

Closest relatives in the guide