Bg 10.31

pavanah pavatam asmi
ramah sastra-bhrtam aham
jhasanam makaras casmi
srotasam asmi jahnavi

Word for word: 
pavanah — the wind; pavatam — of all that purifies; asmi — I am; ramah — Rama; sastra-bhrtam — of the carriers of weapons; aham — I am; jhasanam — of all fish; makarah — the shark; ca — also; asmi — I am; srotasam — of flowing rivers; asmi — I am; jahnavi — the river Ganges.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Of purifiers I am the wind, of the wielders of weapons I am Rama, of fishes I am the shark, and of flowing rivers I am the Ganges.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Of all the aquatics the shark is one of the biggest and is certainly the most dangerous to man. Thus the shark represents Krishna.