Octopuses, squid, and cuttlefish.
Test your knowledge with these top questions!
Which octopus species gathers by the thousands at California's Octopus Garden?
The nursery holds nesting adults, eggs, and hatchlings, but researchers saw no intermediate-sized young or feeding there.
Off which US state was the deep-sea Octopus Garden discovered?
The garden lies more than 3,000 meters deep, so remotely operated vehicles let researchers observe the mothers.
Why do thousands of female octopuses gather at deep-sea octopus gardens?
Pearl octopus mothers live on food reserves for nearly two years while brooding, then die after their eggs hatch.
How does warm seep water affect pearl octopus egg development?
Eggs hatched in under two years at the warm nursery, rather than the five to eight years predicted for cold deep water.
What makes a nautilus eye unusual among cephalopods?
Instead of a lens, a nautilus eye uses a tiny pinhole opening to project an image onto its retina.
Which body part do male cuttlefish use to transfer sperm packets?
A specialized arm called a hectocotylus places sperm packets, or spermatophores, on or in the female.
Octopus blood turns blue because of which oxygen carrier?
Octopus hemocyanin uses copper atoms to carry oxygen, making oxygenated blood appear blue.
What does a cuttlefish's internal cuttlebone mainly control?
The cuttlebone's many chambers help a cuttlefish stay at different depths with little effort.
What do a giant squid's two long tentacles mainly do?
Rows of suckers help each long tentacle grip prey before the eight shorter arms pull the catch inward.
Vampire squid's internal shell evolved into what shape?
The plate resembles a squid's pen, an internal support that stiffens a squid's mantle rather than a chambered shell.