Scorpionfish's ugly visage allows it to hide in northern seaweed beds. Scorpaena plumieri.

Diver observes French angelfish. Pomacanthus paru.

Gag is the most common grouper in the southeast U.S. Mycteroperca microlepis.

Spotted moray eel slithers among the reef growth. Gymnothorax moringa.

Spotted eagle ray soars over Florida Keys reefs. Aetobatus sp.

Green moray eel caught in a fish trap eats the other inmates. Gymnothorax sp.

Nassau grouper eyeing its next meal. Epinephelus striatus.

Jackknife-fish's coloration makes it stand out to potential mates. Equetus lanceolatus.

Garibaldis are common in California kelp-beds. Hypsypops rubicundus.

Seahorse fathers rear their young in a pouch, like kangaroos. Hippocampus erectus.

Juvenile codfish caught in a gill net. Gadus morhua.

A spotted goosefish on basalt boulder in 780 meters off Hawaii

Vase sponge and squirrel fish off NURC station in Bahamas

Jellyfish may be the most common ocean animal, but are hard to catch in nets.

Ctenophore or comb jellyfish feeding.

Ctenophore off New England with long ciliated tentacles.

Lobate ctenophores are translucent and give off a bioluminescent glow. Bolinopsis infundibulum.

Physonect siphonophores are actually colonies of specialized polyps.

Siphonophores are floating cousins to hydroids common on rocks and piers.

Physonect siphonophores are chains of polyps with different functions. Nanomia cara.

Close-up of the tail end of a squid, important prey for commercial fish.

Jellyfish floating under Arctic ice.

A cirrate octopus floats like a bell in mid-water, feeding on plankton.

Jellyfish and their plankton prey concentrate along invisible water boundaries.

Physonect siphonophore is actually a chain of colonial hydroids.

Jellyfish come in many forms, many too fragile to capture in nets.

Some jellyfish pulsate to propel themselves through the water.

Cyanea jellyfish are common on the New England coast in summer.

Crushed lobster left in the path of a scallop drag. Homarus americanus.

Galatheid crabs are common burrow-dwellers on the continental slope. Munida iris.

Octopus live in all oceans, including the muddy deep sea floor.

A dense bed of brittle stars can get their food from the water or bottom. Ophiura sarsii.

Soft corals, crinoids and sea pens need a hard spot for attachment.

Delicate crinoid can orient towards the current to increase food capture.

Sea anemones clustered on a rocky slope off Hawaii.

Feather duster worms, a type of annelid worm, and more specifically, tube- dwelling polychaete worms. The "arms" are actually tentacles or "radioles" at the anterior end of the worm. Most of the worms' bodies are hidden within the tubes they have constructed.

Lobster tangled in a gillnet intended to capture cod and other groundfish. Homarus americanus.

Sea anemones festoon a rocky outcrop off Alaska.

Lobster works a pit in a shell bed. Homarus americanus.

Portunid crab cowering at the base of a cerianthid anemone. Cerianthus borealis (anemone).

Colorful fireworm projecting from a coral head has a sting if touched.

Seastar doen't know what hit it -- arm of a NURP submersible.

Hermit crabs are very particular about their shell homes.

This sea snake is actually a vertebrate and in the wrong place in collection.

Spiny lobster, unlike its northern relative, has no big crusher claw. Panulirus argus

Junvenile lobster use weeds and sponges as refuge.

Golden crabs are the largest crustacean on the continental slope off Florida.

Starfish don't just have five arms-- this sun star has a dozen.

The lobster's large claw can crush crabs, clams and fingers. Homarus americanus.

Cleaner shrimp are distinguished from other shrimp by their long antennae.