You can never have enough tuna.
If you control no monsters, you can Normal Summon this card without a tribute. Once during the opponent’s Standby Phase: You can double the ATK of this card until the End Phase.
This card cannot be used as a Synchro Material. Up to twice per turn, during your Main Phase: You can target 1 Fish-Type Monster on the Field and select 1 of the following effects; apply the selected effect. During the turn in which you activate this effect, you cannot Special Summon monsters, except for WATER monsters.
•Increase the Level of the targeted monster by 1.
•Decrease the Level of the targeted monster by 1.