Do not catch puffer fish and tropical fish in jungle biome

When fishing for book and xp in my constructed fish pond (glass blocks) (5x4x2deep) with 2 salmon in a jungle biome I have caught several stacks of cod and salmon, plus the other usual catches.  But I have not caught a single puffer or tropical fish. Is this just a jungle biome artifact (I also catch jungle specific loot like bamboo and cocoa beans) or is this a bug?