* Fishes move through the water chiefly by means of the caudal fin or tail, the principal office of the other fins being to balance or direct the body, though they are also, to a certain extent, employed in producing motion.

Apidose fin. (Zoöl.) See under Adipose, a. -- Fin ray (Anat.), one of the hornlike, cartilaginous, or bony, dermal rods which form the skeleton of the fins of fishes. -- Fin whale (Zoöl.), a finback. -- Paired fins (Zoöl.), the pectoral and ventral fins, corresponding to the fore and hind legs of the higher animals. -- Unpaired, or Median, fins (Zoöl.), the dorsal, caudal, and anal fins.