The pectoral fins are very large, the ventral fin absent, and there is a very sharp spine in front of each dorsal.
Do not cut off the ventral fin on the side which is to be displayed.
They are known by the position of the ventral fin under the throat, and by the pointed character of those fins.
In the region of the trunk there is present an uninterrupted dorsal fin continuous with a ventral fin round the end of the tail.
The tail, by the development of a dorsal and ventral fin, very soon becomes a powerful swimming organ.
To the lowermost is attached the rudimentary pelvis, which supports the hinder limb or ventral fin.
A dorsal and ventral fin are now clearly visible; they are continuous throughout their whole length.
The backward position of the ventral fin is due to a succession of migrations in the individual and in the species.
The ventral fin which is uppermost as the fish lies on its side and is not to show, should be carefully cut off outside the skin.