Chordata · chordates

Spotted ratfish

Hydrolagus colliei

Chimaeridae · shortnose chimaerasIUCN: Least Concern
Spotted ratfish
Photo: Linda Snook / MBNMS · Public domain · Wikimedia Commons · resized

A chimaera with a rabbit-like face, large green eyes, and a venomous spine.

Fun factMale chimaeras have a toothed clasper on their forehead.

Waters
North Pacific, Eastern Pacific
Depth zone
Continental shelf, Deep sea & continental slope
Diet
Clams, crabs & worms
Size
Up to 1 m

Classification

Chordata › Chondrichthyes › Chimaeridae

  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 Holocephali chimaeras
    • Chimaeras: one gill cover on each side
    • Teeth fused into grinding plates
    • Many have a venomous spine before the first dorsal fin
  9. Family Chimaeridae shortnose chimaeras
    • Shortnose chimaeras (ratfish) with large eyes and a long, tapering tail
  10. Genus Hydrolagus
    • Species in the same genus are very close relatives and often look alike.
  11. Species Hydrolagus colliei Spotted ratfish

Closest relatives in the guide