There are 2 body types and 2 fin types that cannot be produced by breeding (you can get them only from eggs or mutation), and the Twin-Fin and Silky are the two fin types. You can check out our Fish Tycoon Guides Section, where there are a lot of helpful posts.

The strategy you are using works well, as long as you have the Twin-Fin and the Silky in each body type. \:\)
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Barbara
Unicorn
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