Tremoctopus is a genus of pelagic cephalopods, containing four species that occupy surface to mid-waters in subtropical and tropical oceans. They are commonly known as blanket octopuses, in reference to the long, transparent webs that connect the dorsal and dorsolateral arms of the adult females. The other arms are much shorter and lack webbing.
Blanket octopus
Image: Tremoctopus gracilis lower beak (side view)
Image: Tremoctopus gracilis upper beak (side view)
A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.
Cephalopod
The primitive nautilus eye functions similarly to a pinhole camera.
A cuttlefish with W-shaped pupils which may help them discern colors
This broadclub cuttlefish (Sepia latimanus) can change from camouflage tans and browns (top) to yellow with dark highlights (bottom) in less than a second.