Blue dragon

Classification

Mollusca › Gastropoda › Nudibranchia › Glaucidae

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 Protostomia protostomes
   • In the embryo, the first opening usually becomes the mouth
   • Main nerve cord runs along the belly (ventral)
   • Includes mollusks, worms, and arthropods
4. Clade Spiralia mollusks, worms & kin
   • Embryos usually divide in a spiral pattern (spiral cleavage)
   • Many have a swimming larva with a band of cilia (trochophore)
   • Includes mollusks and segmented worms
5. Phylum Mollusca mollusks
   • Soft body with a muscular foot and a fold of tissue (mantle) that makes the shell
   • Most have a rasping, tongue-like ribbon of teeth (radula)
   • Includes snails, clams, octopuses, and chitons
6. Class Gastropoda snails & slugs
   • Snails and slugs, most with a single, often coiled shell
   • Body twists 180 degrees during development (torsion)
   • Crawl on a broad muscular foot
7. Subclass Heterobranchia sea slugs & kin
   • Includes most sea slugs, sea hares, and land and freshwater snails
   • Many marine members have reduced or no shell
8. Order Nudibranchia nudibranchs
   • Shell-less sea slugs, often brightly colored
   • Breathe through feathery gills or finger-like growths (cerata) on the back
   • Many store stinging cells or toxins from their prey
9. Family Glaucidae aeolid nudibranchs
   • Aeolid nudibranchs with clusters of cerata
   • Includes the blue dragon, which floats upside down at the surface
10. Genus Glaucus
    • Species in the same genus are very close relatives and often look alike.
11. Species Glaucus atlanticus Blue dragon

Closest relatives in the guide

• Spanish dancer Hexabranchus sanguineus same order
• Atlantic oyster drill Urosalpinx cinerea same class
• Atlantic slipper snail Crepidula fornicata same class
• California sea hare Aplysia californica same class
• Channeled whelk Busycotypus canaliculatus same class
• Common periwinkle Littorina littorea same class
• Geography cone Conus geographus same class
• Knobbed whelk Busycon carica same class