Teuthowenia megalops

A bathyscaphoid squid (Teuthowenia megalops) swimming in the "cockatoo" posture. The animal rotates around the spindle-shaped digestive gland, which it keeps vertical regardless of the orientation of the mantle and head.
Video courtesy of Estuary to the Abyss 2004 Exploration, Author : George Sedberry, NOAA-OE

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Spiralia
Cladus: Lophotrochozoa
Phylum: Mollusca
Classis: Cephalopoda
Subclassis: Coleoidea
Cohors: Neocoleoidea
Superordo: Decapodiformes
Ordo: Teuthida
Subordo: Oegopsina
Familia: Cranchiidae
Subfamilia: Taoniinae
Genus: Teuthowenia
Species: T. megalops