Non-vertebrate Chordates and Agnathans

There are currently no pictures of juvenile tunicates because I have not been able to take good pictures on a microscope.  As soon as some are available, I will post them here.

This is a (rather blurry) picture of an adult tunicate.

This picture shows the whole mount of Amphioxus as it appears to the naked eye.

This shows a higher magnification of the whole mount slide.

This shows a higher magnification of the rostral end.  You can see the notochord (the portion that goes all the way to the end of the rostrum) and the myomeres and myosepta.  Because of the staining of the muscles, you cannot easily see the nerve cord on this specimen.

This specimen has been stained to show the notochord (a light greenish-blue color) and nerve cord (the pink line that is above the notochord) more clearly.  In addition, you can see the wheel organ and pharyngeal bars and slits.

This shows the first cross sectional view of Amphioxus.  This picture is showing a transverse section that was taken through the area of the mouth.  Notice that the nerve cord has enlarged to a u-shaped structure that would be the animal's brain.

This cross sectional view shows the pharyngeal region.  Note the pharyngeal bars and slits that are visible in this view.  You can also see the myomeres and myosepta.

This cross section is more posterior and shows the intestines quite clearly.

This cross section is in the tail section posterior to the anus, so the only structures you can see are the muscles, the notochord and the nerve cord.

A picture of the external anatomy of the lamprey head (note that the specimen on the practical will NOT be labeled (just in case you were wondering ;)  )

Sagittal section of the lamprey head, unlabeled.

Sagittal section of the lamprey head, labeled

Sagittal section of lamprey, pharyngeal region, labeled.

Transverse section of lamprey, labeled

Ammocoetes larva of lamprey - notice the similarity to the pictures of Amphioxus shown above...