Jellyfish
These stinging cells, located on a jellyfish's tentacles, are used to paralyze prey.
What are nematocysts?
These simplest of multicellular animals belong to this phylum, named for the tiny holes all over their bodies.
What is Porifera?
Cuttlefish are famous for this internal shell used for buoyancy, which is often sold in pet stores for birds to peck at.
What is a cuttlebone?
This is the name of the internal, feather-shaped shell in a squid that supports its mantle.
What is a pen?
An octopus has this many hearts to help pump blood through its body and gills.
What is three?
Jellyfish belong to this phylum, which also includes corals and sea anemones.
What is Cnidaria?
Sponges obtain food through this process, where they strain organic particles and plankton from the water.
What is filter feeding?
To change color and texture instantly, cuttlefish use these specialized pigment-filled sacs in their skin.
What are chromatophores?
This species of squid is the largest known invertebrate on Earth, reaching lengths of up to 43 feet.
What is the Giant Squid?
Because they lack any internal or external skeleton, octopi can fit through any opening as long as it is larger than this body part.
What is the beak?
This "immortal" species of jellyfish can revert its cells to their earliest form when physically damaged or starving.
What is Turritopsis dohrnii?
These specialized flagellated cells, also called collar cells, create the water current that moves through the sponge.
What are choanocytes?
Unlike the circular pupils of humans, cuttlefish have pupils shaped like this letter of the alphabet.
What is W?
Squids use this anatomical structure to expel water forcefully, allowing them to move via jet propulsion.
What is a siphon?
This is the color of octopus blood, which is caused by the copper-based protein hemocyanin.
What is blue?
A group of jellyfish is often referred to by this term, which is also used for a flower's petals.
What is a bloom?
This is the name of the large opening at the top of a sponge through which water is expelled.
What is an osculum?
Cuttlefish belong to this class of mollusks, a name that literally translates to "head-foot."
What is Cephalopoda?
A squid's mouth contains this hard, parrot-like structure used to tear prey apart.
What is a beak?
Two-thirds of an octopus's neurons are actually located here, rather than in its central brain.
What are its arms?
Unlike most animals, jellyfish lack these three major organ systems.
What are the respiratory, circulatory, and central nervous systems?
These structural elements, made of silica or calcium carbonate, act as a "skeleton" for many sponge species.
What are spicules?
Cuttlefish have this many appendages in total, consisting of eight arms and two longer tentacles.
What is ten?
This specific species of squid is famous for its ability to "fly" by ejecting water through its siphon to leap out of the ocean and glide for over 100 feet to escape predators.
What is the neon flying squid?
This specific species of octopus, found in the Pacific and Indian Oceans, is highly venomous and carries enough toxin to kill 26 humans.
What is the Blue-ringed octopus?