Chordata · chordates

Barndoor skate

Dipturus laevis

Rajidae · hardnose skatesIUCN: Least Concern
Barndoor skate
Photo: NEFSC/NOAA · Public domain · Wikimedia Commons · resized

The largest skate in the Northwest Atlantic, once feared nearly extinct.

Fun factAfter seasons of protection, its populations recovered on Georges Bank.

Waters
Northeast US, Northwest Atlantic
Depth zone
Continental shelf, Deep sea & continental slope
Diet
Fish, crabs & squid
Size
Up to 1.5 m

Classification

Chordata › Chondrichthyes › Rajiformes › Rajidae

  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. Superorder Batoidea rays & skates
    • Rays and skates: flattened bodies with gill slits underneath
    • Pectoral fins joined to the head
    • Many have crushing, pavement-like teeth
  10. Order Rajiformes skates
    • Skates: lay leathery egg cases ('mermaid's purses')
    • Many have rows of thorny bumps along the back and tail
  11. Family Rajidae hardnose skates
    • Hardnose skates with a stiff snout
  12. Genus Dipturus
    • Species in the same genus are very close relatives and often look alike.
  13. Species Dipturus laevis Barndoor skate

Closest relatives in the guide