More Anatomy

The feathery strands at the back of this nudibranch’s ( Chromodoris willani ) body are no mere adornment: they’re its gills! Nudibranchs, shell-less snails or sea slugs, are named for these tufted...
Tropical hatchetfish ( Argyropelecus lychnus ), like the one shown in this X-ray photograph, live in the dark depths of the ocean ; this specimen was collected at about 2,789 feet (850 meters) in the...
The elongated body, characteristic long and narrow snout, and small teeth make the slender snipe eel ( Nemichthys scolopaceus ) easily identifiable in this X-ray image. Snipe eels live at great...
This image from a scanning electron micrograph magnifies the tiny teeth that cover the surface of the giant squid’s tongue-like organ, or radula . Seven rows of sharp teeth help direct tiny pieces of...
An X-ray image of a Monterey skate ( Raja montereyensis ) reveals a spine that extends like a tail out from the pelvic fin. The skeletons of skates, rays, chimaeras, and sharks are made of cartilage...
In the X-ray image of this Viper Moray Eel ( Enchelynassa canina ), note the second set of jaws in the “throat”; these are the gill arches, which are present in all fish. Gill arches support the...
A right whale opens its mouth wide, revealing huge plates of baleen hanging from its upper jaw. There are between 200 and 270 baleen plates on each side of a right whale's upper jaw. They work like a...
The distinctive form of a winghead shark ( Eusphyra blochii ) is revealed by an X-ray image. The Winghead Shark, one of about ten species of hammerhead sharks, has its eyes set at the tips of its...
An X-ray image of grooved razorfish ( Centriscus scutatus ). Razorfish are encased in thin, transparent bony plates attached to their spines, which you can see in the X-ray. Also known as shrimpfish...
Hundreds of powerful suckers stud the flattened club at the end of the giant squid’s long feeding tentacle. They help the squid capture and hang on tightly to its prey. They also leave deep scars in...
A mass of white muscle the size of a softball surrounds the dark brown beak of a giant squid. Learn more about this animal's oversized anatomy in our Giant Squid section .
Giant squid have the largest eye in the animal kingdom. At up to 10 inches in diameter, people often describe it as the size of a dinner plate -- or, in other words, as big as a human head. Here,...
The robust oval, spine covered body of a long-spined porcupine fish ( Diodon holocanthus ) is revealed in this X-ray image. To ward off predators, a porcupinefish inflates its body by pumping water...
Comb jellies (such as this Bolinopsis species) are named for their combs: the rows of cilia lining their bodies that propel them through the ocean. Read more about jellyfish and comb jellies .
Inside the giant squid's sharp beak is a tongue-like organ called the radula (shown in yellow). Covered with rows of tiny teeth, it rams bite size pieces of food down the squid's throat. The pieces...
This close-up photo shows the tough, serrated ring around the opening of a giant squid sucker. The ring is made of chitin—the same material that’s in your fingernails. Using suction, the sucker...
Scientists in the Division of Fishes at the Smithsonian's National Museum of Natural History use X-ray imaging to study the complex bone structure and diversity of fish. This image gallery showcases...
Sperm whales have conical teeth on their long, narrow, lower jaw. The teeth fit neatly into sockets in the upper jaw, which has no teeth. This arrangement is a perfect adaptation for slurping up soft...
Subscribe to Anatomy