Cephalopods, Crustaceans, & Other Shellfish Archives - Oceana

Flamboyant Cuttlefish

Pfeffer’s flamboyant cuttlefish is a small cephalopod species that grows to between 6 and 8 cm in size. They are primarily found in the Indian and Pacific Oceans, from southern New Guinea to the north and west coasts of Australia. The flamboyant cuttlefish has two tentacles and eight arms. When pursuing their prey, the cuttlefish … Read more

Hawaiian Bobtail Squid

The squid is a “sit and wait” predator, burying itself in the sand with its eight suckered arms and two tentacles to wait for prey to pass by. They then strike with their tentacles to capture their prey. If they happen to miss their target, the animal will bury itself back in the sand to … Read more

Decorator Crab

The term “decorator crab” describes many different crabs found worldwide, including several different species of spider crabs, harlequin crabs, moss crabs, little seaweed crabs, and toothed crabs. In general, decorator crabs are opportunistic when looking for camouflage, similar to how colorful hermit crabs scavenge their shells. The crab will select pieces of seaweed, coral, rocks, … Read more

Giant Pacific Octopus

Aside from being the largest of all octopuses, the giant Pacific octopus is also recognizable by its typical reddish-pink color. The octopus is equipped with special pigment cells, called chromatophores, just below the surface of the skin that allow it to change color and blend in with rocky or coral-laden surroundings. Octopuses are actually mollusks—their … Read more

Striped Pyjama Squid

Despite its common name, the striped pyjama squid is actually a species of cuttlefish, a versatile animal that can often change its appearance, has an internal shell, eight arms and two feeding tentacles. The striped pyjama squid’s small and rounded appearance like that of a dumpling has inspired other people to commonly refer to it as … Read more


Geoducks are filter feeders. The water that they siphon down to the buried main body is filtered for small particles of food, phytoplankton, pelagic crustaceans, and fish larvae. This water is also the source of the animal’s oxygen and is actively pumped over the gills. This species reproduces through a behavior known as broadcast spawning, where several … Read more

Colorful Hermit Crab

The colorful hermit crab is a large hermit crab that lives along both coasts of South America. Like all hermit crabs, an individual of this species carries around a heavy shell that it uses for protection. It does not build this shell, however. Instead, it scavenges an empty snail shell from a variety of species … Read more

Chambered Nautilus

The chambered nautilus is one of six species of nautilus, the only cephalopods (squids, octopuses, and relatives) that have external shells. Like in most shelled animals, this species can retract completely into its shell when threatened. The chambered nautilus lives in deep waters of the open ocean and is one of very few species of shelled … Read more

Broadclub Cuttlefish

The broadclub cuttlefish is a predatory cephalopod (squid, octopus, or cuttlefish) that lives and hunts on coral reefs in the Indo-Pacific Ocean. This species is the second largest cuttlefish, reaching weights of at least 22 pounds (10 kg). Cuttlefishes are masters of camouflage and can change both their color and the texture of their skin to … Read more

Blue King Crab

The blue king crab is the largest king crab species and one of the largest crustaceans. In the past, this species supported a large fishery, worth millions of dollars, but numbers have been reduced to the point that commercial fishers no longer target the blue king crab directly. It lives on soft bottom habitats throughout … Read more