That'll be the reason, then. My seahorses are 69, 208, and 21. I misremembered; I don't have that MF in the third tank, which no doubt explains why he's so much younger. The 69 year old is actually in the oldest game, and I accidentally sold my breeding pair of that MF, and have only recently bred them back again. The seahorse aged 208 has had the magic fish with it pretty well from when I bought it; it was the first MF I bred in that game, even before the relatively common MF of Fertility.