Use "Superancient Deepsea King Coelacanth" to Special Summon 3 "Deepsea Macrotremas", then Tribute them off for the effect of this card. "Coelacanth" will have also gained 1500 ATK. You must already have this card on the field before you use the effect of "Coelacanth", because "Coelacanth" would negate this card's effect otherwise.
Use "DNA Surgery" and choose Fish to Tribute any Type of monster on your field for this card. This works well with tokens such as "Scapegoat".
"Oyster Meister" is an excellent Tribute for this card effect, giving you 2 monsters to use for this effect.
"Xyz Remora" can give you 3 Tributes for this card's effect.