• 16 bones
  • Checked September 2026

Fish Skeleton Labeled

The skeleton of a bony fish from the side: read each name, then name the bones yourself.

Fish Skeleton Labeled

Name Date

Tap any bone to read, rename or leave it out

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
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Write the name of each numbered bone.Answer key

  1. Skull
  2. Orbit
  3. Premaxilla
  4. Maxilla
  5. Mandible
  6. Operculum
  7. Pectoral girdle
  8. Pelvic bone
  9. Vertebral column
  10. Neural spines
  11. Hemal spines
  12. Ribs
  13. Pterygiophores
  14. Fin spines
  15. Soft rays
  16. Hypural plate

Drawn for this site on 2026-09-30 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a bone is answered.

Next step Next: the skeleton of a frog

All 16 bones on the diagram

Show the list

Head and girdles 8

  1. Skull Many bones, some only loosely joined. It protects the brain and the organs of hearing and smell, and has sockets for the eyes.
  2. Orbit The socket that holds the eye. In the ray-finned fishes the orbits are large.
  3. Premaxilla The front bone of the upper jaw. In a perch it carries teeth.
  4. Maxilla The second bone of the upper jaw. It is set farther back, behind the premaxilla.
  5. Mandible The lower jaw. In a perch it carries teeth, like the premaxilla.
  6. Operculum The bony gill cover. It protects the gills, and water that has passed over them leaves from beneath it.
  7. Pectoral girdle A set of bones just behind the head on each side. It is the firm base for the muscles that move the pectoral fin.
  8. Pelvic bone A flat bone on each side that carries the pelvic fin. Some books call it the pelvic girdle, others the basipterygium.

Backbone and fins 8

  1. Vertebral column The backbone: a row of vertebrae from the skull to the tail. Each vertebra of a fish is hollowed at both ends.
  2. Neural spines One stands on top of each vertebra. It is above the arch the spinal cord runs through. Muscles attach to them.
  3. Hemal spines They hang under the tail vertebrae. Each one ends an arch that the main blood vessels of the tail pass through.
  4. Ribs They frame the body cavity. They hang from the vertebrae of the trunk. A fish has no breastbone for them to join.
  5. Pterygiophores Small bones set between the spines of the vertebrae. Each one carries a ray of a dorsal or anal fin. They are also called interspinal bones.
  6. Fin spines Stiff rays with no joints and no branches. They hold up the first dorsal fin of a perch and the front edge of its anal and pelvic fins.
  7. Soft rays Flexible rays made of many small joints, usually branched at the tip. They hold up the second dorsal, tail and pectoral fins.
  8. Hypural plate A fan of flattened bone at the end of the backbone. The rays of the tail fin spread out from it.

How this list was compiled: Every name checked on 2026-09-30 in two sources. R. W. Hegner, College Zoology (1912, public domain), the skeleton of the perch: skull, jaws, operculum, vertebral column, neural and haemal spines, ribs, pectoral girdle, pelvic bone, pterygiophores, spines and soft rays, https://archive.org/details/collegezoology00hegn. Wikipedia, Fish anatomy and Fish fin, https://en.wikipedia.org/wiki/Fish_anatomy. D. S. Jordan, A Guide to the Study of Fishes (1905, public domain), the skeleton of the striped bass, for the hypural, the interspinal bones and the girdles, https://archive.org/details/guidetostudyoffi01jord. L. H. Hyman, A Laboratory Manual for Comparative Vertebrate Anatomy (1922, public domain), https://archive.org/details/ost-biology-labmanualcompvert00hymarich. Florida Fish and Wildlife Conservation Commission, Fish anatomy, https://myfwc.com/fishing/freshwater/fishing-tips/anatomy/. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work

How it works

This is a bony fish skeleton labeled from the side, drawn on a perch inside the outline of the living fish. It is a plan: the numbers of vertebrae and fin rays are not those of any one species.

Read the full guide

Head and girdles

The skull has a large orbit for the eye. The upper jaw is two bones, the premaxilla in front and the maxilla behind; the lower jaw is the mandible. The operculum covers the gills. Behind it the pectoral girdle carries the pectoral fin, and the pelvic bone carries the pelvic fin.

Backbone and fins

A neural spine stands on every vertebra. Ribs hang from the trunk vertebrae and hemal spines from the tail vertebrae. Pterygiophores sit between the spines and carry the fin spines and soft rays. Press Quiz me, and the fish skeleton with labels becomes a blank one to name.

  • Spines are stiff and have no joints. Soft rays are jointed and usually branch. One fin can have both.

Questions and answers

Do fish have ribs?

Yes. The ribs hang from the vertebrae of the trunk and frame the body cavity. A fish has no breastbone, so the ribs do not join underneath.

What are the fine bones in the flesh of a fish?

Besides the ribs, many fish have intermuscular bones: thin bones that lie in the muscle and are attached to some of the vertebrae.

What is a fish's backbone made of?

A row of vertebrae. Each has a solid middle, the centrum, hollowed at both ends, with an arch above for the spinal cord and, in the tail, an arch below for the main blood vessels.

Do sharks have the same skeleton?

No. A shark's skeleton is made of cartilage, not bone, and a shark has no gill cover.

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