Chordata · chordates

Yellow-bellied sea snake

Hydrophis platurus

Elapidae · cobras, sea snakes & kinIUCN: Least Concern
Yellow-bellied sea snake
Photo: Aloaiza · CC BY 3.0 · Wikimedia Commons · resized

A fully ocean-living snake that drifts along surface slicks.

Fun factIt drinks fresh water from rain layers on the sea surface.

Waters
Eastern Pacific, Indo-Pacific
Depth zone
Open-ocean surface waters
Diet
Small fish
Size
Up to 1 m

Classification

Chordata › Reptilia › Squamata › Elapidae

  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. Superclass Osteichthyes bony vertebrates
    • Bony vertebrates: skeleton made largely of bone
    • Most have a lung or swim bladder
    • Includes ray-finned and lobe-finned fishes and all tetrapods
  8. Clade Sarcopterygii lobe-finned vertebrates
    • Lobe-finned: fleshy fins with bones like those of limbs
    • Includes coelacanths, lungfishes, and all tetrapods
  9. Clade Tetrapoda four-limbed vertebrates
    • Four limbs with fingers and toes (or descended from animals that had them)
    • Breathe air with lungs
  10. Class Reptilia reptiles (birds included)
    • Scaly skin made of keratin
    • Lay shelled eggs on land or carry eggs inside the body (amniotic egg)
    • In modern classification this group includes birds
  11. Order Squamata lizards & snakes
    • Lizards and snakes: skin shed in pieces or whole
    • Flexible skull with a hinged jaw
    • Males have paired reproductive organs (hemipenes)
  12. Family Elapidae cobras, sea snakes & kin
    • Venomous snakes with fixed front fangs
    • Includes cobras and sea snakes; sea snakes have flattened, paddle-like tails
  13. Genus Hydrophis
    • Species in the same genus are very close relatives and often look alike.
  14. Species Hydrophis platurus Yellow-bellied sea snake

Closest relatives in the guide