DOLPHIN: The American Sign Language (ASL) sign for "dolphin"
 

DOLPHIN:
This sign moves from right to left.  The index finger stays straight at the knuckle and the hand moves in a graceful arc as if showing a dolphin slicing through the water.

Another option is to produce the same sign but with an "open-R" handshape:

Sample sentence: DOLPHIN ITSELF FISH-[fs] QM-wig? (Are dolphins fish?)

If you want to learn more animal signs, check out:

Notes:  Also see: ANIMALS