What is the main skeletal difference between salt water eels and lamprey fish besides the jaw

The main skeletal difference between water eels and lamprey is that the body of lamprey lacks bones and has a skeleton made up of cartilage. On the other hand, the skeleton of salt water eels is made up of bones.

Other differences between the two fishes include:

Variation in gills: Lamprey has open gills whereas salt water eels have covered gill slits.

Variation in color: lamprey exists in between colors ranging from brown to blue. On the other hand, salt water eel exists in different shades of the color yellow.