If all monsters you control are WATER monsters (min. 1): You can activate this effect; you cannot Special Summon monsters for the rest of this turn, except WATER monsters, also the next battle damage your opponent takes this turn from a battle involving your "Number" monster and another monster is doubled, also Special Summon this card from your hand, and if you do, add 1 Level 3, 4, or 5 Fish monster from your Deck to your hand, except "Abyss Shark". You can only use this effect of "Abyss Shark" once per turn. If this card is used for the Xyz Summon of a "Number" monster, it can be treated as a Level 3 or 4 monster.